diff options
Diffstat (limited to 'dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/acos/acos_vec3_vert_xvary_ref.vert')
-rw-r--r-- | dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/acos/acos_vec3_vert_xvary_ref.vert | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/acos/acos_vec3_vert_xvary_ref.vert b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/acos/acos_vec3_vert_xvary_ref.vert new file mode 100644 index 0000000000..37ace0f04f --- /dev/null +++ b/dom/canvas/test/webgl-conf/checkout/conformance/ogles/GL/acos/acos_vec3_vert_xvary_ref.vert @@ -0,0 +1,72 @@ + +/* +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. +*/ + + +attribute vec4 gtf_Vertex; +attribute vec4 gtf_Color; +uniform mat4 gtf_ModelViewProjectionMatrix; +varying vec4 color; + +void main (void) +{ + const float M_PI = 3.14159265358979323846; + vec3 c = 2.0 * (gtf_Color.rgb - 0.5); + vec3 acos_c = vec3(0.0); + vec3 scale = vec3(1.0); + vec3 sign = vec3(1.0); + + // pow can't handle negative numbers so take advantage of symmetry + if(c.r < 0.0) + { + sign.r = -1.0; + c.r *= -1.0; + } + + // Taylors series expansion for acos + // 1000/2 iterations necessary to get the accuracy with this method + for(int i = 1; i < 1000; i += 2) + { + acos_c.r += scale.r * pow(c.r, float(i)) / float(i); + scale.r *= float(i) / float(i + 1); + } + acos_c.r = M_PI / 2.0 - sign.r * acos_c.r; + + // pow can't handle negative numbers so take advantage of symmetry + if(c.g < 0.0) + { + sign.g = -1.0; + c.g *= -1.0; + } + + // Taylors series expansion for acos + // 1000/2 iterations necessary to get the accuracy with this method + for(int i = 1; i < 1000; i += 2) + { + acos_c.g += scale.g * pow(c.g, float(i)) / float(i); + scale.g *= float(i) / float(i + 1); + } + acos_c.g = M_PI / 2.0 - sign.g * acos_c.g; + + // pow can't handle negative numbers so take advantage of symmetry + if(c.b < 0.0) + { + sign.b = -1.0; + c.b *= -1.0; + } + + // Taylors series expansion for acos + // 1000/2 iterations necessary to get the accuracy with this method + for(int i = 1; i < 1000; i += 2) + { + acos_c.b += scale.b * pow(c.b, float(i)) / float(i); + scale.b *= float(i) / float(i + 1); + } + acos_c.b = M_PI / 2.0 - sign.b * acos_c.b; + + color = vec4(acos_c / M_PI, 1.0); + gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex; +} |