1192 lines
46 KiB
Metal
1192 lines
46 KiB
Metal
#include <metal_stdlib>
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#include <simd/simd.h>
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using namespace metal;
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float4 hsla_to_rgba(Hsla hsla);
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float3 srgb_to_linear(float3 color);
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float3 linear_to_srgb(float3 color);
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float4 srgb_to_oklab(float4 color);
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float4 oklab_to_srgb(float4 color);
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float4 to_device_position(float2 unit_vertex, Bounds_ScaledPixels bounds,
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constant Size_DevicePixels *viewport_size);
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float4 to_device_position_transformed(float2 unit_vertex, Bounds_ScaledPixels bounds,
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TransformationMatrix transformation,
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constant Size_DevicePixels *input_viewport_size);
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float2 to_tile_position(float2 unit_vertex, AtlasTile tile,
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constant Size_DevicePixels *atlas_size);
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float4 distance_from_clip_rect(float2 unit_vertex, Bounds_ScaledPixels bounds,
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Bounds_ScaledPixels clip_bounds);
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float corner_dash_velocity(float dv1, float dv2);
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float dash_alpha(float t, float period, float length, float dash_velocity,
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float antialias_threshold);
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float quarter_ellipse_sdf(float2 point, float2 radii);
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float pick_corner_radius(float2 center_to_point, Corners_ScaledPixels corner_radii);
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float quad_sdf(float2 point, Bounds_ScaledPixels bounds,
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Corners_ScaledPixels corner_radii);
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float quad_sdf_impl(float2 center_to_point, float corner_radius);
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float gaussian(float x, float sigma);
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float2 erf(float2 x);
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float blur_along_x(float x, float y, float sigma, float corner,
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float2 half_size);
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float4 over(float4 below, float4 above);
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float radians(float degrees);
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float4 fill_color(Background background, float2 position, Bounds_ScaledPixels bounds,
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float4 solid_color, float4 color0, float4 color1);
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struct GradientColor {
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float4 solid;
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float4 color0;
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float4 color1;
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};
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GradientColor prepare_fill_color(uint tag, uint color_space, Hsla solid, Hsla color0, Hsla color1);
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struct QuadVertexOutput {
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uint quad_id [[flat]];
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float4 position [[position]];
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float4 border_color [[flat]];
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float4 background_solid [[flat]];
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float4 background_color0 [[flat]];
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float4 background_color1 [[flat]];
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float clip_distance [[clip_distance]][4];
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};
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struct QuadFragmentInput {
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uint quad_id [[flat]];
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float4 position [[position]];
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float4 border_color [[flat]];
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float4 background_solid [[flat]];
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float4 background_color0 [[flat]];
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float4 background_color1 [[flat]];
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};
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vertex QuadVertexOutput quad_vertex(uint unit_vertex_id [[vertex_id]],
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uint quad_id [[instance_id]],
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constant float2 *unit_vertices
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[[buffer(QuadInputIndex_Vertices)]],
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constant Quad *quads
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[[buffer(QuadInputIndex_Quads)]],
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constant Size_DevicePixels *viewport_size
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[[buffer(QuadInputIndex_ViewportSize)]]) {
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float2 unit_vertex = unit_vertices[unit_vertex_id];
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Quad quad = quads[quad_id];
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float4 device_position =
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to_device_position(unit_vertex, quad.bounds, viewport_size);
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float4 clip_distance = distance_from_clip_rect(unit_vertex, quad.bounds,
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quad.content_mask.bounds);
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float4 border_color = hsla_to_rgba(quad.border_color);
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GradientColor gradient = prepare_fill_color(
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quad.background.tag,
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quad.background.color_space,
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quad.background.solid,
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quad.background.colors[0].color,
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quad.background.colors[1].color
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);
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return QuadVertexOutput{
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quad_id,
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device_position,
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border_color,
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gradient.solid,
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gradient.color0,
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gradient.color1,
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{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
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}
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fragment float4 quad_fragment(QuadFragmentInput input [[stage_in]],
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constant Quad *quads
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[[buffer(QuadInputIndex_Quads)]]) {
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Quad quad = quads[input.quad_id];
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float4 background_color = fill_color(quad.background, input.position.xy, quad.bounds,
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input.background_solid, input.background_color0, input.background_color1);
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bool unrounded = quad.corner_radii.top_left == 0.0 &&
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quad.corner_radii.bottom_left == 0.0 &&
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quad.corner_radii.top_right == 0.0 &&
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quad.corner_radii.bottom_right == 0.0;
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// Fast path when the quad is not rounded and doesn't have any border
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if (quad.border_widths.top == 0.0 &&
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quad.border_widths.left == 0.0 &&
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quad.border_widths.right == 0.0 &&
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quad.border_widths.bottom == 0.0 &&
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unrounded) {
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return background_color;
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}
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float2 size = float2(quad.bounds.size.width, quad.bounds.size.height);
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float2 half_size = size / 2.0;
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float2 point = input.position.xy - float2(quad.bounds.origin.x, quad.bounds.origin.y);
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float2 center_to_point = point - half_size;
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// Signed distance field threshold for inclusion of pixels. 0.5 is the
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// minimum distance between the center of the pixel and the edge.
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const float antialias_threshold = 0.5;
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// Radius of the nearest corner
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float corner_radius = pick_corner_radius(center_to_point, quad.corner_radii);
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// Width of the nearest borders
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float2 border = float2(
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center_to_point.x < 0.0 ? quad.border_widths.left : quad.border_widths.right,
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center_to_point.y < 0.0 ? quad.border_widths.top : quad.border_widths.bottom
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);
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// 0-width borders are reduced so that `inner_sdf >= antialias_threshold`.
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// The purpose of this is to not draw antialiasing pixels in this case.
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float2 reduced_border = float2(
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border.x == 0.0 ? -antialias_threshold : border.x,
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border.y == 0.0 ? -antialias_threshold : border.y);
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// Vector from the corner of the quad bounds to the point, after mirroring
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// the point into the bottom right quadrant. Both components are <= 0.
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float2 corner_to_point = fabs(center_to_point) - half_size;
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// Vector from the point to the center of the rounded corner's circle, also
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// mirrored into bottom right quadrant.
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float2 corner_center_to_point = corner_to_point + corner_radius;
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// Whether the nearest point on the border is rounded
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bool is_near_rounded_corner =
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corner_center_to_point.x >= 0.0 &&
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corner_center_to_point.y >= 0.0;
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// Vector from straight border inner corner to point.
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//
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// 0-width borders are turned into width -1 so that inner_sdf is > 1.0 near
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// the border. Without this, antialiasing pixels would be drawn.
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float2 straight_border_inner_corner_to_point = corner_to_point + reduced_border;
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// Whether the point is beyond the inner edge of the straight border
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bool is_beyond_inner_straight_border =
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straight_border_inner_corner_to_point.x > 0.0 ||
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straight_border_inner_corner_to_point.y > 0.0;
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// Whether the point is far enough inside the quad, such that the pixels are
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// not affected by the straight border.
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bool is_within_inner_straight_border =
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straight_border_inner_corner_to_point.x < -antialias_threshold &&
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straight_border_inner_corner_to_point.y < -antialias_threshold;
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// Fast path for points that must be part of the background
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if (is_within_inner_straight_border && !is_near_rounded_corner) {
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return background_color;
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}
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// Signed distance of the point to the outside edge of the quad's border
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float outer_sdf = quad_sdf_impl(corner_center_to_point, corner_radius);
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// Approximate signed distance of the point to the inside edge of the quad's
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// border. It is negative outside this edge (within the border), and
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// positive inside.
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//
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// This is not always an accurate signed distance:
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// * The rounded portions with varying border width use an approximation of
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// nearest-point-on-ellipse.
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// * When it is quickly known to be outside the edge, -1.0 is used.
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float inner_sdf = 0.0;
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if (corner_center_to_point.x <= 0.0 || corner_center_to_point.y <= 0.0) {
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// Fast paths for straight borders
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inner_sdf = -max(straight_border_inner_corner_to_point.x,
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straight_border_inner_corner_to_point.y);
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} else if (is_beyond_inner_straight_border) {
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// Fast path for points that must be outside the inner edge
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inner_sdf = -1.0;
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} else if (reduced_border.x == reduced_border.y) {
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// Fast path for circular inner edge.
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inner_sdf = -(outer_sdf + reduced_border.x);
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} else {
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float2 ellipse_radii = max(float2(0.0), float2(corner_radius) - reduced_border);
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inner_sdf = quarter_ellipse_sdf(corner_center_to_point, ellipse_radii);
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}
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// Negative when inside the border
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float border_sdf = max(inner_sdf, outer_sdf);
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float4 color = background_color;
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if (border_sdf < antialias_threshold) {
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float4 border_color = input.border_color;
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// Dashed border logic when border_style == 1
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if (quad.border_style == 1) {
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// Position along the perimeter in "dash space", where each dash
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// period has length 1
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float t = 0.0;
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// Total number of dash periods, so that the dash spacing can be
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// adjusted to evenly divide it
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float max_t = 0.0;
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// Border width is proportional to dash size. This is the behavior
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// used by browsers, but also avoids dashes from different segments
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// overlapping when dash size is smaller than the border width.
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//
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// Dash pattern: (2 * border width) dash, (1 * border width) gap
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const float dash_length_per_width = 2.0;
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const float dash_gap_per_width = 1.0;
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const float dash_period_per_width = dash_length_per_width + dash_gap_per_width;
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// Since the dash size is determined by border width, the density of
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// dashes varies. Multiplying a pixel distance by this returns a
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// position in dash space - it has units (dash period / pixels). So
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// a dash velocity of (1 / 10) is 1 dash every 10 pixels.
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float dash_velocity = 0.0;
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// Dividing this by the border width gives the dash velocity
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const float dv_numerator = 1.0 / dash_period_per_width;
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if (unrounded) {
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// When corners aren't rounded, the dashes are separately laid
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// out on each straight line, rather than around the whole
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// perimeter. This way each line starts and ends with a dash.
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bool is_horizontal = corner_center_to_point.x < corner_center_to_point.y;
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float border_width = is_horizontal ? border.x : border.y;
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dash_velocity = dv_numerator / border_width;
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t = is_horizontal ? point.x : point.y;
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t *= dash_velocity;
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max_t = is_horizontal ? size.x : size.y;
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max_t *= dash_velocity;
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} else {
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// When corners are rounded, the dashes are laid out clockwise
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// around the whole perimeter.
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float r_tr = quad.corner_radii.top_right;
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float r_br = quad.corner_radii.bottom_right;
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float r_bl = quad.corner_radii.bottom_left;
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float r_tl = quad.corner_radii.top_left;
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float w_t = quad.border_widths.top;
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float w_r = quad.border_widths.right;
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float w_b = quad.border_widths.bottom;
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float w_l = quad.border_widths.left;
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// Straight side dash velocities
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float dv_t = w_t <= 0.0 ? 0.0 : dv_numerator / w_t;
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float dv_r = w_r <= 0.0 ? 0.0 : dv_numerator / w_r;
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float dv_b = w_b <= 0.0 ? 0.0 : dv_numerator / w_b;
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float dv_l = w_l <= 0.0 ? 0.0 : dv_numerator / w_l;
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// Straight side lengths in dash space
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float s_t = (size.x - r_tl - r_tr) * dv_t;
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float s_r = (size.y - r_tr - r_br) * dv_r;
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float s_b = (size.x - r_br - r_bl) * dv_b;
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float s_l = (size.y - r_bl - r_tl) * dv_l;
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float corner_dash_velocity_tr = corner_dash_velocity(dv_t, dv_r);
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float corner_dash_velocity_br = corner_dash_velocity(dv_b, dv_r);
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float corner_dash_velocity_bl = corner_dash_velocity(dv_b, dv_l);
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float corner_dash_velocity_tl = corner_dash_velocity(dv_t, dv_l);
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// Corner lengths in dash space
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float c_tr = r_tr * (M_PI_F / 2.0) * corner_dash_velocity_tr;
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float c_br = r_br * (M_PI_F / 2.0) * corner_dash_velocity_br;
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float c_bl = r_bl * (M_PI_F / 2.0) * corner_dash_velocity_bl;
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float c_tl = r_tl * (M_PI_F / 2.0) * corner_dash_velocity_tl;
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// Cumulative dash space upto each segment
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float upto_tr = s_t;
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float upto_r = upto_tr + c_tr;
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float upto_br = upto_r + s_r;
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float upto_b = upto_br + c_br;
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float upto_bl = upto_b + s_b;
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float upto_l = upto_bl + c_bl;
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float upto_tl = upto_l + s_l;
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max_t = upto_tl + c_tl;
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if (is_near_rounded_corner) {
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float radians = atan2(corner_center_to_point.y, corner_center_to_point.x);
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float corner_t = radians * corner_radius * dash_velocity;
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if (center_to_point.x >= 0.0) {
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if (center_to_point.y < 0.0) {
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dash_velocity = corner_dash_velocity_tr;
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// Subtracted because radians is pi/2 to 0 when
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// going clockwise around the top right corner,
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// since the y axis has been flipped
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t = upto_r - corner_t;
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} else {
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dash_velocity = corner_dash_velocity_br;
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// Added because radians is 0 to pi/2 when going
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// clockwise around the bottom-right corner
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t = upto_br + corner_t;
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}
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} else {
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if (center_to_point.y >= 0.0) {
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dash_velocity = corner_dash_velocity_bl;
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// Subtracted because radians is pi/1 to 0 when
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// going clockwise around the bottom-left corner,
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// since the x axis has been flipped
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t = upto_l - corner_t;
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} else {
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dash_velocity = corner_dash_velocity_tl;
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// Added because radians is 0 to pi/2 when going
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// clockwise around the top-left corner, since both
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// axis were flipped
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t = upto_tl + corner_t;
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}
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}
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} else {
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// Straight borders
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bool is_horizontal = corner_center_to_point.x < corner_center_to_point.y;
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if (is_horizontal) {
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if (center_to_point.y < 0.0) {
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dash_velocity = dv_t;
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t = (point.x - r_tl) * dash_velocity;
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} else {
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dash_velocity = dv_b;
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t = upto_bl - (point.x - r_bl) * dash_velocity;
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}
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} else {
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if (center_to_point.x < 0.0) {
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dash_velocity = dv_l;
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t = upto_tl - (point.y - r_tl) * dash_velocity;
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} else {
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dash_velocity = dv_r;
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t = upto_r + (point.y - r_tr) * dash_velocity;
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}
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}
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}
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}
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float dash_length = dash_length_per_width / dash_period_per_width;
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float desired_dash_gap = dash_gap_per_width / dash_period_per_width;
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// Straight borders should start and end with a dash, so max_t is
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// reduced to cause this.
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max_t -= unrounded ? dash_length : 0.0;
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if (max_t >= 1.0) {
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// Adjust dash gap to evenly divide max_t
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float dash_count = floor(max_t);
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float dash_period = max_t / dash_count;
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border_color.a *= dash_alpha(t, dash_period, dash_length, dash_velocity,
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antialias_threshold);
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} else if (unrounded) {
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// When there isn't enough space for the full gap between the
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// two start / end dashes of a straight border, reduce gap to
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// make them fit.
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float dash_gap = max_t - dash_length;
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if (dash_gap > 0.0) {
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float dash_period = dash_length + dash_gap;
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border_color.a *= dash_alpha(t, dash_period, dash_length, dash_velocity,
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antialias_threshold);
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}
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}
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}
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// Blend the border on top of the background and then linearly interpolate
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// between the two as we slide inside the background.
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float4 blended_border = over(background_color, border_color);
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color = mix(background_color, blended_border,
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saturate(antialias_threshold - inner_sdf));
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}
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return color * float4(1.0, 1.0, 1.0, saturate(antialias_threshold - outer_sdf));
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}
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// Returns the dash velocity of a corner given the dash velocity of the two
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// sides, by returning the slower velocity (larger dashes).
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//
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// Since 0 is used for dash velocity when the border width is 0 (instead of
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// +inf), this returns the other dash velocity in that case.
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//
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// An alternative to this might be to appropriately interpolate the dash
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// velocity around the corner, but that seems overcomplicated.
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float corner_dash_velocity(float dv1, float dv2) {
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if (dv1 == 0.0) {
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return dv2;
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} else if (dv2 == 0.0) {
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return dv1;
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} else {
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return min(dv1, dv2);
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}
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}
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// Returns alpha used to render antialiased dashes.
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// `t` is within the dash when `fmod(t, period) < length`.
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float dash_alpha(
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float t, float period, float length, float dash_velocity,
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float antialias_threshold) {
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float half_period = period / 2.0;
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float half_length = length / 2.0;
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// Value in [-half_period, half_period]
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// The dash is in [-half_length, half_length]
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float centered = fmod(t + half_period - half_length, period) - half_period;
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// Signed distance for the dash, negative values are inside the dash
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float signed_distance = abs(centered) - half_length;
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// Antialiased alpha based on the signed distance
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return saturate(antialias_threshold - signed_distance / dash_velocity);
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}
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// This approximates distance to the nearest point to a quarter ellipse in a way
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// that is sufficient for anti-aliasing when the ellipse is not very eccentric.
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// The components of `point` are expected to be positive.
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//
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// Negative on the outside and positive on the inside.
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float quarter_ellipse_sdf(float2 point, float2 radii) {
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// Scale the space to treat the ellipse like a unit circle
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float2 circle_vec = point / radii;
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float unit_circle_sdf = length(circle_vec) - 1.0;
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// Approximate up-scaling of the length by using the average of the radii.
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//
|
|
// TODO: A better solution would be to use the gradient of the implicit
|
|
// function for an ellipse to approximate a scaling factor.
|
|
return unit_circle_sdf * (radii.x + radii.y) * -0.5;
|
|
}
|
|
|
|
struct ShadowVertexOutput {
|
|
float4 position [[position]];
|
|
float4 color [[flat]];
|
|
uint shadow_id [[flat]];
|
|
float clip_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct ShadowFragmentInput {
|
|
float4 position [[position]];
|
|
float4 color [[flat]];
|
|
uint shadow_id [[flat]];
|
|
};
|
|
|
|
vertex ShadowVertexOutput shadow_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint shadow_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(ShadowInputIndex_Vertices)]],
|
|
constant Shadow *shadows [[buffer(ShadowInputIndex_Shadows)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(ShadowInputIndex_ViewportSize)]]) {
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
Shadow shadow = shadows[shadow_id];
|
|
|
|
float margin = 3. * shadow.blur_radius;
|
|
// Set the bounds of the shadow and adjust its size based on the shadow's
|
|
// spread radius to achieve the spreading effect
|
|
Bounds_ScaledPixels bounds = shadow.bounds;
|
|
bounds.origin.x -= margin;
|
|
bounds.origin.y -= margin;
|
|
bounds.size.width += 2. * margin;
|
|
bounds.size.height += 2. * margin;
|
|
|
|
float4 device_position =
|
|
to_device_position(unit_vertex, bounds, viewport_size);
|
|
float4 clip_distance =
|
|
distance_from_clip_rect(unit_vertex, bounds, shadow.content_mask.bounds);
|
|
float4 color = hsla_to_rgba(shadow.color);
|
|
|
|
return ShadowVertexOutput{
|
|
device_position,
|
|
color,
|
|
shadow_id,
|
|
{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
|
|
}
|
|
|
|
fragment float4 shadow_fragment(ShadowFragmentInput input [[stage_in]],
|
|
constant Shadow *shadows
|
|
[[buffer(ShadowInputIndex_Shadows)]]) {
|
|
Shadow shadow = shadows[input.shadow_id];
|
|
|
|
float2 origin = float2(shadow.bounds.origin.x, shadow.bounds.origin.y);
|
|
float2 size = float2(shadow.bounds.size.width, shadow.bounds.size.height);
|
|
float2 half_size = size / 2.;
|
|
float2 center = origin + half_size;
|
|
float2 point = input.position.xy - center;
|
|
float corner_radius;
|
|
if (point.x < 0.) {
|
|
if (point.y < 0.) {
|
|
corner_radius = shadow.corner_radii.top_left;
|
|
} else {
|
|
corner_radius = shadow.corner_radii.bottom_left;
|
|
}
|
|
} else {
|
|
if (point.y < 0.) {
|
|
corner_radius = shadow.corner_radii.top_right;
|
|
} else {
|
|
corner_radius = shadow.corner_radii.bottom_right;
|
|
}
|
|
}
|
|
|
|
float alpha;
|
|
if (shadow.blur_radius == 0.) {
|
|
float distance = quad_sdf(input.position.xy, shadow.bounds, shadow.corner_radii);
|
|
alpha = saturate(0.5 - distance);
|
|
} else {
|
|
// The signal is only non-zero in a limited range, so don't waste samples
|
|
float low = point.y - half_size.y;
|
|
float high = point.y + half_size.y;
|
|
float start = clamp(-3. * shadow.blur_radius, low, high);
|
|
float end = clamp(3. * shadow.blur_radius, low, high);
|
|
|
|
// Accumulate samples (we can get away with surprisingly few samples)
|
|
float step = (end - start) / 4.;
|
|
float y = start + step * 0.5;
|
|
alpha = 0.;
|
|
for (int i = 0; i < 4; i++) {
|
|
alpha += blur_along_x(point.x, point.y - y, shadow.blur_radius,
|
|
corner_radius, half_size) *
|
|
gaussian(y, shadow.blur_radius) * step;
|
|
y += step;
|
|
}
|
|
}
|
|
|
|
return input.color * float4(1., 1., 1., alpha);
|
|
}
|
|
|
|
struct UnderlineVertexOutput {
|
|
float4 position [[position]];
|
|
float4 color [[flat]];
|
|
uint underline_id [[flat]];
|
|
float clip_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct UnderlineFragmentInput {
|
|
float4 position [[position]];
|
|
float4 color [[flat]];
|
|
uint underline_id [[flat]];
|
|
};
|
|
|
|
vertex UnderlineVertexOutput underline_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint underline_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(UnderlineInputIndex_Vertices)]],
|
|
constant Underline *underlines [[buffer(UnderlineInputIndex_Underlines)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(ShadowInputIndex_ViewportSize)]]) {
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
Underline underline = underlines[underline_id];
|
|
float4 device_position =
|
|
to_device_position(unit_vertex, underline.bounds, viewport_size);
|
|
float4 clip_distance = distance_from_clip_rect(unit_vertex, underline.bounds,
|
|
underline.content_mask.bounds);
|
|
float4 color = hsla_to_rgba(underline.color);
|
|
return UnderlineVertexOutput{
|
|
device_position,
|
|
color,
|
|
underline_id,
|
|
{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
|
|
}
|
|
|
|
fragment float4 underline_fragment(UnderlineFragmentInput input [[stage_in]],
|
|
constant Underline *underlines
|
|
[[buffer(UnderlineInputIndex_Underlines)]]) {
|
|
Underline underline = underlines[input.underline_id];
|
|
if (underline.wavy) {
|
|
float half_thickness = underline.thickness * 0.5;
|
|
float2 origin =
|
|
float2(underline.bounds.origin.x, underline.bounds.origin.y);
|
|
float2 st = ((input.position.xy - origin) / underline.bounds.size.height) -
|
|
float2(0., 0.5);
|
|
float frequency = (M_PI_F * (3. * underline.thickness)) / 8.;
|
|
float amplitude = 1. / (2. * underline.thickness);
|
|
float sine = sin(st.x * frequency) * amplitude;
|
|
float dSine = cos(st.x * frequency) * amplitude * frequency;
|
|
float distance = (st.y - sine) / sqrt(1. + dSine * dSine);
|
|
float distance_in_pixels = distance * underline.bounds.size.height;
|
|
float distance_from_top_border = distance_in_pixels - half_thickness;
|
|
float distance_from_bottom_border = distance_in_pixels + half_thickness;
|
|
float alpha = saturate(
|
|
0.5 - max(-distance_from_bottom_border, distance_from_top_border));
|
|
return input.color * float4(1., 1., 1., alpha);
|
|
} else {
|
|
return input.color;
|
|
}
|
|
}
|
|
|
|
struct MonochromeSpriteVertexOutput {
|
|
float4 position [[position]];
|
|
float2 tile_position;
|
|
float4 color [[flat]];
|
|
float clip_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct MonochromeSpriteFragmentInput {
|
|
float4 position [[position]];
|
|
float2 tile_position;
|
|
float4 color [[flat]];
|
|
};
|
|
|
|
vertex MonochromeSpriteVertexOutput monochrome_sprite_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
|
|
constant MonochromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(SpriteInputIndex_ViewportSize)]],
|
|
constant Size_DevicePixels *atlas_size
|
|
[[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
MonochromeSprite sprite = sprites[sprite_id];
|
|
float4 device_position =
|
|
to_device_position_transformed(unit_vertex, sprite.bounds, sprite.transformation, viewport_size);
|
|
float4 clip_distance = distance_from_clip_rect(unit_vertex, sprite.bounds,
|
|
sprite.content_mask.bounds);
|
|
float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
|
|
float4 color = hsla_to_rgba(sprite.color);
|
|
return MonochromeSpriteVertexOutput{
|
|
device_position,
|
|
tile_position,
|
|
color,
|
|
{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
|
|
}
|
|
|
|
fragment float4 monochrome_sprite_fragment(
|
|
MonochromeSpriteFragmentInput input [[stage_in]],
|
|
constant MonochromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
|
|
constexpr sampler atlas_texture_sampler(mag_filter::linear,
|
|
min_filter::linear);
|
|
float4 sample =
|
|
atlas_texture.sample(atlas_texture_sampler, input.tile_position);
|
|
float4 color = input.color;
|
|
color.a *= sample.a;
|
|
return color;
|
|
}
|
|
|
|
struct PolychromeSpriteVertexOutput {
|
|
float4 position [[position]];
|
|
float2 tile_position;
|
|
uint sprite_id [[flat]];
|
|
float clip_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct PolychromeSpriteFragmentInput {
|
|
float4 position [[position]];
|
|
float2 tile_position;
|
|
uint sprite_id [[flat]];
|
|
};
|
|
|
|
vertex PolychromeSpriteVertexOutput polychrome_sprite_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
|
|
constant PolychromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(SpriteInputIndex_ViewportSize)]],
|
|
constant Size_DevicePixels *atlas_size
|
|
[[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
|
|
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
PolychromeSprite sprite = sprites[sprite_id];
|
|
float4 device_position =
|
|
to_device_position(unit_vertex, sprite.bounds, viewport_size);
|
|
float4 clip_distance = distance_from_clip_rect(unit_vertex, sprite.bounds,
|
|
sprite.content_mask.bounds);
|
|
float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
|
|
return PolychromeSpriteVertexOutput{
|
|
device_position,
|
|
tile_position,
|
|
sprite_id,
|
|
{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
|
|
}
|
|
|
|
fragment float4 polychrome_sprite_fragment(
|
|
PolychromeSpriteFragmentInput input [[stage_in]],
|
|
constant PolychromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
|
|
PolychromeSprite sprite = sprites[input.sprite_id];
|
|
constexpr sampler atlas_texture_sampler(mag_filter::linear,
|
|
min_filter::linear);
|
|
float4 sample =
|
|
atlas_texture.sample(atlas_texture_sampler, input.tile_position);
|
|
float distance =
|
|
quad_sdf(input.position.xy, sprite.bounds, sprite.corner_radii);
|
|
|
|
float4 color = sample;
|
|
if (sprite.grayscale) {
|
|
float grayscale = 0.2126 * color.r + 0.7152 * color.g + 0.0722 * color.b;
|
|
color.r = grayscale;
|
|
color.g = grayscale;
|
|
color.b = grayscale;
|
|
}
|
|
color.a *= sprite.opacity * saturate(0.5 - distance);
|
|
return color;
|
|
}
|
|
|
|
struct PathRasterizationVertexOutput {
|
|
float4 position [[position]];
|
|
float2 st_position;
|
|
float clip_rect_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct PathRasterizationFragmentInput {
|
|
float4 position [[position]];
|
|
float2 st_position;
|
|
};
|
|
|
|
vertex PathRasterizationVertexOutput path_rasterization_vertex(
|
|
uint vertex_id [[vertex_id]],
|
|
constant PathVertex_ScaledPixels *vertices
|
|
[[buffer(PathRasterizationInputIndex_Vertices)]],
|
|
constant Size_DevicePixels *atlas_size
|
|
[[buffer(PathRasterizationInputIndex_AtlasTextureSize)]]) {
|
|
PathVertex_ScaledPixels v = vertices[vertex_id];
|
|
float2 vertex_position = float2(v.xy_position.x, v.xy_position.y);
|
|
float2 viewport_size = float2(atlas_size->width, atlas_size->height);
|
|
return PathRasterizationVertexOutput{
|
|
float4(vertex_position / viewport_size * float2(2., -2.) +
|
|
float2(-1., 1.),
|
|
0., 1.),
|
|
float2(v.st_position.x, v.st_position.y),
|
|
{v.xy_position.x - v.content_mask.bounds.origin.x,
|
|
v.content_mask.bounds.origin.x + v.content_mask.bounds.size.width -
|
|
v.xy_position.x,
|
|
v.xy_position.y - v.content_mask.bounds.origin.y,
|
|
v.content_mask.bounds.origin.y + v.content_mask.bounds.size.height -
|
|
v.xy_position.y}};
|
|
}
|
|
|
|
fragment float4 path_rasterization_fragment(PathRasterizationFragmentInput input
|
|
[[stage_in]]) {
|
|
float2 dx = dfdx(input.st_position);
|
|
float2 dy = dfdy(input.st_position);
|
|
float2 gradient = float2((2. * input.st_position.x) * dx.x - dx.y,
|
|
(2. * input.st_position.x) * dy.x - dy.y);
|
|
float f = (input.st_position.x * input.st_position.x) - input.st_position.y;
|
|
float distance = f / length(gradient);
|
|
float alpha = saturate(0.5 - distance);
|
|
return float4(alpha, 0., 0., 1.);
|
|
}
|
|
|
|
struct PathSpriteVertexOutput {
|
|
float4 position [[position]];
|
|
float2 tile_position;
|
|
uint sprite_id [[flat]];
|
|
float4 solid_color [[flat]];
|
|
float4 color0 [[flat]];
|
|
float4 color1 [[flat]];
|
|
};
|
|
|
|
vertex PathSpriteVertexOutput path_sprite_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
|
|
constant PathSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(SpriteInputIndex_ViewportSize)]],
|
|
constant Size_DevicePixels *atlas_size
|
|
[[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
|
|
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
PathSprite sprite = sprites[sprite_id];
|
|
// Don't apply content mask because it was already accounted for when
|
|
// rasterizing the path.
|
|
float4 device_position =
|
|
to_device_position(unit_vertex, sprite.bounds, viewport_size);
|
|
float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
|
|
|
|
GradientColor gradient = prepare_fill_color(
|
|
sprite.color.tag,
|
|
sprite.color.color_space,
|
|
sprite.color.solid,
|
|
sprite.color.colors[0].color,
|
|
sprite.color.colors[1].color
|
|
);
|
|
|
|
return PathSpriteVertexOutput{
|
|
device_position,
|
|
tile_position,
|
|
sprite_id,
|
|
gradient.solid,
|
|
gradient.color0,
|
|
gradient.color1
|
|
};
|
|
}
|
|
|
|
fragment float4 path_sprite_fragment(
|
|
PathSpriteVertexOutput input [[stage_in]],
|
|
constant PathSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
|
|
texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
|
|
constexpr sampler atlas_texture_sampler(mag_filter::linear,
|
|
min_filter::linear);
|
|
float4 sample =
|
|
atlas_texture.sample(atlas_texture_sampler, input.tile_position);
|
|
float mask = 1. - abs(1. - fmod(sample.r, 2.));
|
|
PathSprite sprite = sprites[input.sprite_id];
|
|
Background background = sprite.color;
|
|
float4 color = fill_color(background, input.position.xy, sprite.bounds,
|
|
input.solid_color, input.color0, input.color1);
|
|
color.a *= mask;
|
|
return color;
|
|
}
|
|
|
|
struct SurfaceVertexOutput {
|
|
float4 position [[position]];
|
|
float2 texture_position;
|
|
float clip_distance [[clip_distance]][4];
|
|
};
|
|
|
|
struct SurfaceFragmentInput {
|
|
float4 position [[position]];
|
|
float2 texture_position;
|
|
};
|
|
|
|
vertex SurfaceVertexOutput surface_vertex(
|
|
uint unit_vertex_id [[vertex_id]], uint surface_id [[instance_id]],
|
|
constant float2 *unit_vertices [[buffer(SurfaceInputIndex_Vertices)]],
|
|
constant SurfaceBounds *surfaces [[buffer(SurfaceInputIndex_Surfaces)]],
|
|
constant Size_DevicePixels *viewport_size
|
|
[[buffer(SurfaceInputIndex_ViewportSize)]],
|
|
constant Size_DevicePixels *texture_size
|
|
[[buffer(SurfaceInputIndex_TextureSize)]]) {
|
|
float2 unit_vertex = unit_vertices[unit_vertex_id];
|
|
SurfaceBounds surface = surfaces[surface_id];
|
|
float4 device_position =
|
|
to_device_position(unit_vertex, surface.bounds, viewport_size);
|
|
float4 clip_distance = distance_from_clip_rect(unit_vertex, surface.bounds,
|
|
surface.content_mask.bounds);
|
|
// We are going to copy the whole texture, so the texture position corresponds
|
|
// to the current vertex of the unit triangle.
|
|
float2 texture_position = unit_vertex;
|
|
return SurfaceVertexOutput{
|
|
device_position,
|
|
texture_position,
|
|
{clip_distance.x, clip_distance.y, clip_distance.z, clip_distance.w}};
|
|
}
|
|
|
|
fragment float4 surface_fragment(SurfaceFragmentInput input [[stage_in]],
|
|
texture2d<float> y_texture
|
|
[[texture(SurfaceInputIndex_YTexture)]],
|
|
texture2d<float> cb_cr_texture
|
|
[[texture(SurfaceInputIndex_CbCrTexture)]]) {
|
|
constexpr sampler texture_sampler(mag_filter::linear, min_filter::linear);
|
|
const float4x4 ycbcrToRGBTransform =
|
|
float4x4(float4(+1.0000f, +1.0000f, +1.0000f, +0.0000f),
|
|
float4(+0.0000f, -0.3441f, +1.7720f, +0.0000f),
|
|
float4(+1.4020f, -0.7141f, +0.0000f, +0.0000f),
|
|
float4(-0.7010f, +0.5291f, -0.8860f, +1.0000f));
|
|
float4 ycbcr = float4(
|
|
y_texture.sample(texture_sampler, input.texture_position).r,
|
|
cb_cr_texture.sample(texture_sampler, input.texture_position).rg, 1.0);
|
|
|
|
return ycbcrToRGBTransform * ycbcr;
|
|
}
|
|
|
|
float4 hsla_to_rgba(Hsla hsla) {
|
|
float h = hsla.h * 6.0; // Now, it's an angle but scaled in [0, 6) range
|
|
float s = hsla.s;
|
|
float l = hsla.l;
|
|
float a = hsla.a;
|
|
|
|
float c = (1.0 - fabs(2.0 * l - 1.0)) * s;
|
|
float x = c * (1.0 - fabs(fmod(h, 2.0) - 1.0));
|
|
float m = l - c / 2.0;
|
|
|
|
float r = 0.0;
|
|
float g = 0.0;
|
|
float b = 0.0;
|
|
|
|
if (h >= 0.0 && h < 1.0) {
|
|
r = c;
|
|
g = x;
|
|
b = 0.0;
|
|
} else if (h >= 1.0 && h < 2.0) {
|
|
r = x;
|
|
g = c;
|
|
b = 0.0;
|
|
} else if (h >= 2.0 && h < 3.0) {
|
|
r = 0.0;
|
|
g = c;
|
|
b = x;
|
|
} else if (h >= 3.0 && h < 4.0) {
|
|
r = 0.0;
|
|
g = x;
|
|
b = c;
|
|
} else if (h >= 4.0 && h < 5.0) {
|
|
r = x;
|
|
g = 0.0;
|
|
b = c;
|
|
} else {
|
|
r = c;
|
|
g = 0.0;
|
|
b = x;
|
|
}
|
|
|
|
float4 rgba;
|
|
rgba.x = (r + m);
|
|
rgba.y = (g + m);
|
|
rgba.z = (b + m);
|
|
rgba.w = a;
|
|
return rgba;
|
|
}
|
|
|
|
float3 srgb_to_linear(float3 color) {
|
|
return pow(color, float3(2.2));
|
|
}
|
|
|
|
float3 linear_to_srgb(float3 color) {
|
|
return pow(color, float3(1.0 / 2.2));
|
|
}
|
|
|
|
// Converts a sRGB color to the Oklab color space.
|
|
// Reference: https://bottosson.github.io/posts/oklab/#converting-from-linear-srgb-to-oklab
|
|
float4 srgb_to_oklab(float4 color) {
|
|
// Convert non-linear sRGB to linear sRGB
|
|
color = float4(srgb_to_linear(color.rgb), color.a);
|
|
|
|
float l = 0.4122214708 * color.r + 0.5363325363 * color.g + 0.0514459929 * color.b;
|
|
float m = 0.2119034982 * color.r + 0.6806995451 * color.g + 0.1073969566 * color.b;
|
|
float s = 0.0883024619 * color.r + 0.2817188376 * color.g + 0.6299787005 * color.b;
|
|
|
|
float l_ = pow(l, 1.0/3.0);
|
|
float m_ = pow(m, 1.0/3.0);
|
|
float s_ = pow(s, 1.0/3.0);
|
|
|
|
return float4(
|
|
0.2104542553 * l_ + 0.7936177850 * m_ - 0.0040720468 * s_,
|
|
1.9779984951 * l_ - 2.4285922050 * m_ + 0.4505937099 * s_,
|
|
0.0259040371 * l_ + 0.7827717662 * m_ - 0.8086757660 * s_,
|
|
color.a
|
|
);
|
|
}
|
|
|
|
// Converts an Oklab color to the sRGB color space.
|
|
float4 oklab_to_srgb(float4 color) {
|
|
float l_ = color.r + 0.3963377774 * color.g + 0.2158037573 * color.b;
|
|
float m_ = color.r - 0.1055613458 * color.g - 0.0638541728 * color.b;
|
|
float s_ = color.r - 0.0894841775 * color.g - 1.2914855480 * color.b;
|
|
|
|
float l = l_ * l_ * l_;
|
|
float m = m_ * m_ * m_;
|
|
float s = s_ * s_ * s_;
|
|
|
|
float3 linear_rgb = float3(
|
|
4.0767416621 * l - 3.3077115913 * m + 0.2309699292 * s,
|
|
-1.2684380046 * l + 2.6097574011 * m - 0.3413193965 * s,
|
|
-0.0041960863 * l - 0.7034186147 * m + 1.7076147010 * s
|
|
);
|
|
|
|
// Convert linear sRGB to non-linear sRGB
|
|
return float4(linear_to_srgb(linear_rgb), color.a);
|
|
}
|
|
|
|
float4 to_device_position(float2 unit_vertex, Bounds_ScaledPixels bounds,
|
|
constant Size_DevicePixels *input_viewport_size) {
|
|
float2 position =
|
|
unit_vertex * float2(bounds.size.width, bounds.size.height) +
|
|
float2(bounds.origin.x, bounds.origin.y);
|
|
float2 viewport_size = float2((float)input_viewport_size->width,
|
|
(float)input_viewport_size->height);
|
|
float2 device_position =
|
|
position / viewport_size * float2(2., -2.) + float2(-1., 1.);
|
|
return float4(device_position, 0., 1.);
|
|
}
|
|
|
|
float4 to_device_position_transformed(float2 unit_vertex, Bounds_ScaledPixels bounds,
|
|
TransformationMatrix transformation,
|
|
constant Size_DevicePixels *input_viewport_size) {
|
|
float2 position =
|
|
unit_vertex * float2(bounds.size.width, bounds.size.height) +
|
|
float2(bounds.origin.x, bounds.origin.y);
|
|
|
|
// Apply the transformation matrix to the position via matrix multiplication.
|
|
float2 transformed_position = float2(0, 0);
|
|
transformed_position[0] = position[0] * transformation.rotation_scale[0][0] + position[1] * transformation.rotation_scale[0][1];
|
|
transformed_position[1] = position[0] * transformation.rotation_scale[1][0] + position[1] * transformation.rotation_scale[1][1];
|
|
|
|
// Add in the translation component of the transformation matrix.
|
|
transformed_position[0] += transformation.translation[0];
|
|
transformed_position[1] += transformation.translation[1];
|
|
|
|
float2 viewport_size = float2((float)input_viewport_size->width,
|
|
(float)input_viewport_size->height);
|
|
float2 device_position =
|
|
transformed_position / viewport_size * float2(2., -2.) + float2(-1., 1.);
|
|
return float4(device_position, 0., 1.);
|
|
}
|
|
|
|
|
|
float2 to_tile_position(float2 unit_vertex, AtlasTile tile,
|
|
constant Size_DevicePixels *atlas_size) {
|
|
float2 tile_origin = float2(tile.bounds.origin.x, tile.bounds.origin.y);
|
|
float2 tile_size = float2(tile.bounds.size.width, tile.bounds.size.height);
|
|
return (tile_origin + unit_vertex * tile_size) /
|
|
float2((float)atlas_size->width, (float)atlas_size->height);
|
|
}
|
|
|
|
// Selects corner radius based on quadrant.
|
|
float pick_corner_radius(float2 center_to_point, Corners_ScaledPixels corner_radii) {
|
|
if (center_to_point.x < 0.) {
|
|
if (center_to_point.y < 0.) {
|
|
return corner_radii.top_left;
|
|
} else {
|
|
return corner_radii.bottom_left;
|
|
}
|
|
} else {
|
|
if (center_to_point.y < 0.) {
|
|
return corner_radii.top_right;
|
|
} else {
|
|
return corner_radii.bottom_right;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Signed distance of the point to the quad's border - positive outside the
|
|
// border, and negative inside.
|
|
float quad_sdf(float2 point, Bounds_ScaledPixels bounds,
|
|
Corners_ScaledPixels corner_radii) {
|
|
float2 half_size = float2(bounds.size.width, bounds.size.height) / 2.0;
|
|
float2 center = float2(bounds.origin.x, bounds.origin.y) + half_size;
|
|
float2 center_to_point = point - center;
|
|
float corner_radius = pick_corner_radius(center_to_point, corner_radii);
|
|
float2 corner_to_point = fabs(center_to_point) - half_size;
|
|
float2 corner_center_to_point = corner_to_point + corner_radius;
|
|
return quad_sdf_impl(corner_center_to_point, corner_radius);
|
|
}
|
|
|
|
// Implementation of quad signed distance field
|
|
float quad_sdf_impl(float2 corner_center_to_point, float corner_radius) {
|
|
if (corner_radius == 0.0) {
|
|
// Fast path for unrounded corners
|
|
return max(corner_center_to_point.x, corner_center_to_point.y);
|
|
} else {
|
|
// Signed distance of the point from a quad that is inset by corner_radius
|
|
// It is negative inside this quad, and positive outside
|
|
float signed_distance_to_inset_quad =
|
|
// 0 inside the inset quad, and positive outside
|
|
length(max(float2(0.0), corner_center_to_point)) +
|
|
// 0 outside the inset quad, and negative inside
|
|
min(0.0, max(corner_center_to_point.x, corner_center_to_point.y));
|
|
|
|
return signed_distance_to_inset_quad - corner_radius;
|
|
}
|
|
}
|
|
|
|
// A standard gaussian function, used for weighting samples
|
|
float gaussian(float x, float sigma) {
|
|
return exp(-(x * x) / (2. * sigma * sigma)) / (sqrt(2. * M_PI_F) * sigma);
|
|
}
|
|
|
|
// This approximates the error function, needed for the gaussian integral
|
|
float2 erf(float2 x) {
|
|
float2 s = sign(x);
|
|
float2 a = abs(x);
|
|
float2 r1 = 1. + (0.278393 + (0.230389 + (0.000972 + 0.078108 * a) * a) * a) * a;
|
|
float2 r2 = r1 * r1;
|
|
return s - s / (r2 * r2);
|
|
}
|
|
|
|
float blur_along_x(float x, float y, float sigma, float corner,
|
|
float2 half_size) {
|
|
float delta = min(half_size.y - corner - abs(y), 0.);
|
|
float curved =
|
|
half_size.x - corner + sqrt(max(0., corner * corner - delta * delta));
|
|
float2 integral =
|
|
0.5 + 0.5 * erf((x + float2(-curved, curved)) * (sqrt(0.5) / sigma));
|
|
return integral.y - integral.x;
|
|
}
|
|
|
|
float4 distance_from_clip_rect(float2 unit_vertex, Bounds_ScaledPixels bounds,
|
|
Bounds_ScaledPixels clip_bounds) {
|
|
float2 position =
|
|
unit_vertex * float2(bounds.size.width, bounds.size.height) +
|
|
float2(bounds.origin.x, bounds.origin.y);
|
|
return float4(position.x - clip_bounds.origin.x,
|
|
clip_bounds.origin.x + clip_bounds.size.width - position.x,
|
|
position.y - clip_bounds.origin.y,
|
|
clip_bounds.origin.y + clip_bounds.size.height - position.y);
|
|
}
|
|
|
|
float4 over(float4 below, float4 above) {
|
|
float4 result;
|
|
float alpha = above.a + below.a * (1.0 - above.a);
|
|
result.rgb =
|
|
(above.rgb * above.a + below.rgb * below.a * (1.0 - above.a)) / alpha;
|
|
result.a = alpha;
|
|
return result;
|
|
}
|
|
|
|
GradientColor prepare_fill_color(uint tag, uint color_space, Hsla solid,
|
|
Hsla color0, Hsla color1) {
|
|
GradientColor out;
|
|
if (tag == 0 || tag == 2) {
|
|
out.solid = hsla_to_rgba(solid);
|
|
} else if (tag == 1) {
|
|
out.color0 = hsla_to_rgba(color0);
|
|
out.color1 = hsla_to_rgba(color1);
|
|
|
|
// Prepare color space in vertex for avoid conversion
|
|
// in fragment shader for performance reasons
|
|
if (color_space == 1) {
|
|
// Oklab
|
|
out.color0 = srgb_to_oklab(out.color0);
|
|
out.color1 = srgb_to_oklab(out.color1);
|
|
}
|
|
}
|
|
|
|
return out;
|
|
}
|
|
|
|
float2x2 rotate2d(float angle) {
|
|
float s = sin(angle);
|
|
float c = cos(angle);
|
|
return float2x2(c, -s, s, c);
|
|
}
|
|
|
|
float4 fill_color(Background background,
|
|
float2 position,
|
|
Bounds_ScaledPixels bounds,
|
|
float4 solid_color, float4 color0, float4 color1) {
|
|
float4 color;
|
|
|
|
switch (background.tag) {
|
|
case 0:
|
|
color = solid_color;
|
|
break;
|
|
case 1: {
|
|
// -90 degrees to match the CSS gradient angle.
|
|
float gradient_angle = background.gradient_angle_or_pattern_height;
|
|
float radians = (fmod(gradient_angle, 360.0) - 90.0) * (M_PI_F / 180.0);
|
|
float2 direction = float2(cos(radians), sin(radians));
|
|
|
|
// Expand the short side to be the same as the long side
|
|
if (bounds.size.width > bounds.size.height) {
|
|
direction.y *= bounds.size.height / bounds.size.width;
|
|
} else {
|
|
direction.x *= bounds.size.width / bounds.size.height;
|
|
}
|
|
|
|
// Get the t value for the linear gradient with the color stop percentages.
|
|
float2 half_size = float2(bounds.size.width, bounds.size.height) / 2.;
|
|
float2 center = float2(bounds.origin.x, bounds.origin.y) + half_size;
|
|
float2 center_to_point = position - center;
|
|
float t = dot(center_to_point, direction) / length(direction);
|
|
// Check the direction to determine whether to use x or y
|
|
if (abs(direction.x) > abs(direction.y)) {
|
|
t = (t + half_size.x) / bounds.size.width;
|
|
} else {
|
|
t = (t + half_size.y) / bounds.size.height;
|
|
}
|
|
|
|
// Adjust t based on the stop percentages
|
|
t = (t - background.colors[0].percentage)
|
|
/ (background.colors[1].percentage
|
|
- background.colors[0].percentage);
|
|
t = clamp(t, 0.0, 1.0);
|
|
|
|
switch (background.color_space) {
|
|
case 0:
|
|
color = mix(color0, color1, t);
|
|
break;
|
|
case 1: {
|
|
float4 oklab_color = mix(color0, color1, t);
|
|
color = oklab_to_srgb(oklab_color);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 2: {
|
|
float gradient_angle_or_pattern_height = background.gradient_angle_or_pattern_height;
|
|
float pattern_width = (gradient_angle_or_pattern_height / 65535.0f) / 255.0f;
|
|
float pattern_interval = fmod(gradient_angle_or_pattern_height, 65535.0f) / 255.0f;
|
|
float pattern_height = pattern_width + pattern_interval;
|
|
float stripe_angle = M_PI_F / 4.0;
|
|
float pattern_period = pattern_height * sin(stripe_angle);
|
|
float2x2 rotation = rotate2d(stripe_angle);
|
|
float2 relative_position = position - float2(bounds.origin.x, bounds.origin.y);
|
|
float2 rotated_point = rotation * relative_position;
|
|
float pattern = fmod(rotated_point.x, pattern_period);
|
|
float distance = min(pattern, pattern_period - pattern) - pattern_period * (pattern_width / pattern_height) / 2.0f;
|
|
color = solid_color;
|
|
color.a *= saturate(0.5 - distance);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return color;
|
|
}
|