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Diffstat (limited to '')
| -rw-r--r-- | dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/dFdx/dFdx_frag.frag | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/dFdx/dFdx_frag.frag b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/dFdx/dFdx_frag.frag new file mode 100644 index 0000000000..4371f9a7fc --- /dev/null +++ b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/dFdx/dFdx_frag.frag @@ -0,0 +1,51 @@ + +/* +Copyright (c) 2019 The Khronos Group Inc. +Use of this source code is governed by an MIT-style license that can be +found in the LICENSE.txt file. +*/ + + +#ifdef GL_ES +#extension GL_OES_standard_derivatives : enable +precision mediump float; +#endif + +// setting a boundary for cases where screen sizes may exceed the precision +// of the arithmetic used. +#define SAFETY_BOUND 500.0 + +// Macro to scale/bias the range of output. If input is [-1.0, 1.0], maps to [0.5, 1.0].. +// Accounts for precision errors magnified by derivative operation. +#define REDUCE_RANGE(A) ((A) + 3.0) / 4.0 + +// This fragment shader computes an image representation of the derivative of +// sine. The derivative of sine is cosine. This shader's output is compared to +// the reference shader that computes an image representation of cosine +// directly. + +uniform float viewportwidth; +uniform float viewportheight; + +varying vec2 vertXY; + +void main (void) +{ + const float M_PI = 3.14159265358979323846; + float sine; + float cosine; + +#ifdef GL_OES_standard_derivatives + sine = sin(fract(gl_FragCoord.x / 128.0) * (2.0 * M_PI)); + cosine = REDUCE_RANGE((128.0 / (2.0 * M_PI)) * dFdx(sine)); +#else + cosine = 0.5; +#endif + + if( gl_FragCoord.x < SAFETY_BOUND ) + { + gl_FragColor = vec4(cosine, cosine, cosine, 1.0); + } + else discard; +} + |