shaders: add skia shaders

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

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

1 files changed, 46 insertions, 0 deletions

diff --git a/shaders/skia/4-73.shader_test b/shaders/skia/4-73.shader_test
new file mode 100644
index 0000000..3de5b55
--- /dev/null
+++ b/shaders/skia/4-73.shader_test
@@ -0,0 +1,46 @@
+[require]
+GLSL >= 1.40
+
+[fragment shader]
+#version 140
+
+out vec4 sk_FragColor;
+uniform vec4 uColor_Stage0;
+noperspective in vec3 vDashParam_Stage0;
+noperspective in vec2 vCircleParams_Stage0;
+void main() {
+    vec4 outputColor_Stage0;
+    vec4 outputCoverage_Stage0;
+    {
+        outputColor_Stage0 = uColor_Stage0;
+        float xShifted = vDashParam_Stage0.x - floor(vDashParam_Stage0.x / vDashParam_Stage0.z) * vDashParam_Stage0.z;
+        vec2 fragPosShifted = vec2(xShifted, vDashParam_Stage0.y);
+        vec2 center = vec2(vCircleParams_Stage0.y, 0.0);
+        float dist = length(center - fragPosShifted);
+        float diff = dist - vCircleParams_Stage0.x;
+        diff = 1.0 - diff;
+        float alpha = clamp(diff, 0.0, 1.0);
+        outputCoverage_Stage0 = vec4(alpha);
+    }
+    {
+        sk_FragColor = outputColor_Stage0 * outputCoverage_Stage0;
+    }
+}
+
+[vertex shader]
+#version 140
+
+uniform vec4 sk_RTAdjust;
+in vec2 inPosition;
+in vec3 inDashParams;
+in vec2 inCircleParams;
+noperspective out vec3 vDashParam_Stage0;
+noperspective out vec2 vCircleParams_Stage0;
+void main() {
+    vDashParam_Stage0 = inDashParams;
+    vCircleParams_Stage0 = inCircleParams;
+    vec2 pos2 = inPosition;
+    gl_Position = vec4(pos2.x, pos2.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);
+}
+