Add ToT WebGL conformance tests : part 9

conformance/ogles/GL/atan/atan_vec3_vert_xvaryyvary.vert

+
+/*
+** Copyright (c) 2012 The Khronos Group Inc.
+**
+** Permission is hereby granted, free of charge, to any person obtaining a
+** copy of this software and/or associated documentation files (the
+** "Materials"), to deal in the Materials without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Materials, and to
+** permit persons to whom the Materials are furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be included
+** in all copies or substantial portions of the Materials.
+**
+** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+*/
+
+
+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 x = 2.0 * (gtf_Color.ggg - 0.5);
+        vec3 y = 2.0 * (gtf_Color.bbb - 0.5);
+        const float epsilon = 1.0e-4;
+        color = vec4(0.0, 0.0, 0.0, 1.0);
+        
+        // Avoid evaluating atan(0, x) for x < epsilon because it's implementation-dependent
+        if(x[0] > epsilon || abs(y[0]) > epsilon)
+        {
+                color[0] = atan(y[0], x[0]) / (2.0 * M_PI) + 0.5;
+        }
+
+        if(x[1] > epsilon || abs(y[1]) > epsilon)
+        {
+                color[1] = atan(y[1], x[1]) / (2.0 * M_PI) + 0.5;
+        }
+
+        if(x[2] > epsilon || abs(y[2]) > epsilon)
+        {
+                color[2] = atan(y[2], x[2]) / (2.0 * M_PI) + 0.5;
+        }
+        
+        gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex;
+}