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Diffstat (limited to '')
-rw-r--r-- | dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/atan/atan_float_frag_xvary_ref.frag | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/atan/atan_float_frag_xvary_ref.frag b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/atan/atan_float_frag_xvary_ref.frag new file mode 100644 index 0000000000..83546d9d72 --- /dev/null +++ b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/atan/atan_float_frag_xvary_ref.frag @@ -0,0 +1,55 @@ + +/* +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 +precision mediump float; +#endif +varying vec4 color; + +void main (void) +{ + const float M_PI = 3.14159265358979323846; + float c = 4.0 * 2.0 * (color.r - 0.5); + float atan_c = 0.0; + float scale = 1.0; + float sign = 1.0; + vec4 result; + + if(c < 0.0) + { + sign = -1.0; + c *= -1.0; + } + + if(c <= 1.0) + { + // Taylors series expansion for atan + for(int i = 1; i < 12; i += 2) + { + atan_c += scale * pow(c, float(i)) / float(i); + scale *= -1.0; + } + + result = vec4(sign * atan_c / M_PI + 0.5, 0.0, 0.0, 1.0); + } + else + { + c = 1.0 / c; + + // Taylors series expansion for atan + for(int i = 1; i < 12; i += 2) + { + atan_c += scale * pow(c, float(i)) / float(i); + scale *= -1.0; + } + + result = vec4(sign * (M_PI / 2.0 - atan_c) / M_PI + 0.5, 0.0, 0.0, 1.0); + } + + gl_FragColor = result; +} |