shaders: add skia shaders

Add shaders extracted from skia's unit tests[1]

[1] https://skia.org/dev/testing/testing

1 files changed, 124 insertions, 0 deletions

diff --git a/shaders/skia/28-18.shader_test b/shaders/skia/28-18.shader_test
new file mode 100644
index 0000000..d220364
--- /dev/null
+++ b/shaders/skia/28-18.shader_test
@@ -0,0 +1,124 @@
+[require]
+GLSL >= 1.40
+
+[fragment shader]
+#version 140
+
+out vec4 sk_FragColor;
+uniform vec4 uleftBorderColor_Stage1_c0_c0;
+uniform vec4 urightBorderColor_Stage1_c0_c0;
+uniform vec4 uscale01_Stage1_c0_c0_c1_c0;
+uniform vec4 ubias01_Stage1_c0_c0_c1_c0;
+uniform vec4 uscale23_Stage1_c0_c0_c1_c0;
+uniform vec4 ubias23_Stage1_c0_c0_c1_c0;
+uniform float uthreshold_Stage1_c0_c0_c1_c0;
+uniform vec4 ucolor_Stage2_c1_c0_c0_c0;
+uniform vec4 ucolor_Stage2_c2_c0_c0_c0;
+noperspective in vec2 vTransformedCoords_0_Stage0;
+flat in vec4 vcolor_Stage0;
+vec4 RadialGradientLayout_Stage1_c0_c0_c0_c0(vec4 _input) {
+    vec4 _output;
+    float t = length(vTransformedCoords_0_Stage0);
+    _output = vec4(t, 1.0, 0.0, 0.0);
+    return _output;
+}
+vec4 DualIntervalGradientColorizer_Stage1_c0_c0_c1_c0(vec4 _input) {
+    vec4 _output;
+    float t = _input.x;
+    vec4 scale, bias;
+    if (t < uthreshold_Stage1_c0_c0_c1_c0) {
+        scale = uscale01_Stage1_c0_c0_c1_c0;
+        bias = ubias01_Stage1_c0_c0_c1_c0;
+    } else {
+        scale = uscale23_Stage1_c0_c0_c1_c0;
+        bias = ubias23_Stage1_c0_c0_c1_c0;
+    }
+    _output = t * scale + bias;
+    return _output;
+}
+vec4 ClampedGradientEffect_Stage1_c0_c0(vec4 _input) {
+    vec4 _output;
+    vec4 t = RadialGradientLayout_Stage1_c0_c0_c0_c0(vec4(1.0));
+    if (t.x < 0.0) {
+        _output = uleftBorderColor_Stage1_c0_c0;
+    } else if (t.x > 1.0) {
+        _output = urightBorderColor_Stage1_c0_c0;
+    } else {
+        _output = DualIntervalGradientColorizer_Stage1_c0_c0_c1_c0(t);
+    }
+    return _output;
+}
+vec4 ConstColorProcessor_Stage2_c1_c0_c0_c0(vec4 _input) {
+    vec4 _output;
+    {
+        _output = ucolor_Stage2_c1_c0_c0_c0;
+    }
+    return _output;
+}
+float _blend_overlay_component(float sc, float sa, float dc, float da) {
+    if (2.0 * dc <= da) {
+        return (2.0 * sc) * dc;
+    }
+    return sa * da - (2.0 * (da - dc)) * (sa - sc);
+}
+vec4 blend_overlay(vec4 src, vec4 dst) {
+    vec4 result = vec4(_blend_overlay_component(src.x, src.w, dst.x, dst.w), _blend_overlay_component(src.y, src.w, dst.y, dst.w), _blend_overlay_component(src.z, src.w, dst.z, dst.w), src.w + (1.0 - src.w) * dst.w);
+    result.xyz += dst.xyz * (1.0 - src.w) + src.xyz * (1.0 - dst.w);
+    return result;
+}
+vec4 ComposeOne_Stage2_c1_c0(vec4 _input) {
+    vec4 _output;
+    _output = blend_overlay(ConstColorProcessor_Stage2_c1_c0_c0_c0(vec4(1.0)), _input);
+    return _output;
+}
+vec4 ConstColorProcessor_Stage2_c2_c0_c0_c0(vec4 _input) {
+    vec4 _output;
+    {
+        _output = ucolor_Stage2_c2_c0_c0_c0;
+    }
+    return _output;
+}
+vec4 blend_src_over(vec4 src, vec4 dst) {
+    return src + (1.0 - src.w) * dst;
+}
+vec4 blend_darken(vec4 src, vec4 dst) {
+    vec4 result = blend_src_over(src, dst);
+    result.xyz = min(result.xyz, (1.0 - dst.w) * src.xyz + dst.xyz);
+    return result;
+}
+vec4 ComposeOne_Stage2_c2_c0(vec4 _input) {
+    vec4 _output;
+    _output = blend_darken(ConstColorProcessor_Stage2_c2_c0_c0_c0(vec4(1.0)), _input);
+    return _output;
+}
+void main() {
+    vec4 output_Stage1;
+    {
+        output_Stage1 = ClampedGradientEffect_Stage1_c0_c0(vec4(1.0, 1.0, 1.0, 1.0));
+    }
+    vec4 output_Stage2;
+    {
+        output_Stage2 = ComposeOne_Stage2_c2_c0(ComposeOne_Stage2_c1_c0(output_Stage1));
+    }
+    {
+        sk_FragColor = output_Stage2;
+    }
+}
+
+[vertex shader]
+#version 140
+
+uniform vec4 sk_RTAdjust;
+uniform mat3 uCoordTransformMatrix_0_Stage0;
+in vec2 position;
+in vec4 color;
+in vec2 localCoord;
+noperspective out vec2 vTransformedCoords_0_Stage0;
+flat out vec4 vcolor_Stage0;
+void main() {
+    vTransformedCoords_0_Stage0 = (uCoordTransformMatrix_0_Stage0 * vec3(localCoord, 1.0)).xy;
+    vcolor_Stage0 = color;
+    gl_Position = vec4(position.x, position.y, 0.0, 1.0);
+    gl_Position = vec4(gl_Position.xy * sk_RTAdjust.xz + gl_Position.ww * sk_RTAdjust.yw, 0.0, gl_Position.w);
+}
+