diff options
Diffstat (limited to 'dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/fwidth/fwidth_frag_ref.frag')
| -rw-r--r-- | dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/fwidth/fwidth_frag_ref.frag | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/fwidth/fwidth_frag_ref.frag b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/fwidth/fwidth_frag_ref.frag new file mode 100644 index 0000000000..c80b0007d1 --- /dev/null +++ b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL2ExtensionTests/fwidth/fwidth_frag_ref.frag @@ -0,0 +1,47 @@ + +/* +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 + + +uniform float viewportwidth; +uniform float viewportheight; + +varying vec2 vertXY; + +void main (void) +{ + const float M_PI = 3.14159265358979323846; + float func; + + if( (gl_FragCoord.x < SAFETY_BOUND) && (gl_FragCoord.y < SAFETY_BOUND) ) + { + // average of horizontal and vertical abs cosine waves with periods of 128 pixels + +#ifdef GL_OES_standard_derivatives + func = REDUCE_RANGE(0.5 * (abs(cos(fract(gl_FragCoord.x / 128.0) * (2.0 * M_PI))) + abs(cos(fract(gl_FragCoord.y / 128.0) * (2.0 * M_PI))))); +#else + func = 0.5; +#endif + + gl_FragColor = vec4(func, func, func, 1.0); + } + else discard; +} + |