shaders: add skia shaders

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

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

1 files changed, 56 insertions, 0 deletions

diff --git a/shaders/skia/1171.shader_test b/shaders/skia/1171.shader_test
new file mode 100644
index 0000000..ef083dd
--- /dev/null
+++ b/shaders/skia/1171.shader_test
@@ -0,0 +1,56 @@
+[require]
+GLSL >= 1.40
+
+[fragment shader]
+#version 140
+
+#extension GL_ARB_fragment_coord_conventions : require
+layout(origin_upper_left) in vec4 gl_FragCoord;
+out vec4 sk_FragColor;
+uniform vec4 uinnerRect_Stage1;
+uniform vec2 uinvRadiiXY_Stage1;
+noperspective in vec4 vcolor_Stage0;
+noperspective in float vinCoverage_Stage0;
+void main() {
+    vec4 outputCoverage_Stage0;
+    {
+        float alpha = 1.0;
+        alpha = vinCoverage_Stage0;
+        outputCoverage_Stage0 = vec4(alpha);
+    }
+    vec4 output_Stage1;
+    {
+        vec2 dxy0 = uinnerRect_Stage1.xy - gl_FragCoord.xy;
+        vec2 dxy1 = gl_FragCoord.xy - uinnerRect_Stage1.zw;
+        vec2 dxy = max(max(dxy0, dxy1), 0.0);
+        vec2 Z = dxy * uinvRadiiXY_Stage1;
+        float implicit = dot(Z, dxy) - 1.0;
+        float grad_dot = 4.0 * dot(Z, Z);
+        grad_dot = max(grad_dot, 9.9999997473787516e-05);
+        float approx_dist = implicit * inversesqrt(grad_dot);
+        float alpha = clamp(0.5 + approx_dist, 0.0, 1.0);
+        output_Stage1 = outputCoverage_Stage0 * alpha;
+    }
+    {
+        sk_FragColor = output_Stage1;
+    }
+}
+
+[vertex shader]
+#version 140
+
+uniform vec4 sk_RTAdjust;
+in vec2 inPosition;
+in vec4 inColor;
+in float inCoverage;
+noperspective out vec4 vcolor_Stage0;
+noperspective out float vinCoverage_Stage0;
+void main() {
+    vec4 color = inColor;
+    vcolor_Stage0 = color;
+    vec2 pos2 = inPosition;
+    vinCoverage_Stage0 = inCoverage;
+    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);
+}
+