Add ToT WebGL conformance tests : part 9

conformance/ogles/GL/atan/atan_vec2_vert_xvaryyvary_ref.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;
+        vec2 x = 2.0 * (gtf_Color.gg - 0.5);
+        vec2 y = 2.0 * (gtf_Color.bb - 0.5);
+        vec2 c;
+        vec2 atan_c = vec2(0.0);
+        vec2 scale = vec2(1.0);
+        vec2 sign = vec2(1.0);
+        vec4 result = vec4(0.0, 0.0, 0.0, 1.0);
+        const float epsilon = 1.0e-4;
+
+        // Avoid evaluating atan(0, x) for x < epsilon because it's implementation-dependent
+        if(x[0] > epsilon || abs(y[0]) > epsilon)
+        {
+                if(x[0] < 0.0 ^^ y[0] < 0.0)
+                {
+                        sign[0] = -1.0;
+                }
+
+                if(abs(y[0]) <= abs(x[0]))
+                {
+                        c[0] = abs(y[0] / x[0]);
+                        // Taylors series expansion for atan
+                        atan_c[0] += scale[0] * pow(c[0], float(1)) / float(1);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(3)) / float(3);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(5)) / float(5);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(7)) / float(7);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(9)) / float(9);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(11)) / float(11);
+                        scale[0] *= -1.0;
+
+                        result[0] = sign[0] * atan_c[0] / (2.0 * M_PI) + 0.5;
+                }
+                else
+                {
+                        c[0] = abs(x[0] / y[0]);
+
+                        // Taylors series expansion for atan
+                        atan_c[0] += scale[0] * pow(c[0], float(1)) / float(1);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(3)) / float(3);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(5)) / float(5);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(7)) / float(7);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(9)) / float(9);
+                        scale[0] *= -1.0;
+                        atan_c[0] += scale[0] * pow(c[0], float(11)) / float(11);
+                        scale[0] *= -1.0;
+
+                        result[0] = sign[0] * (M_PI / 2.0 - atan_c[0]) / (2.0 * M_PI) + 0.5;
+                }
+
+                if(x[0] < 0.0)
+                        if(y[0] < 0.0) result[0] -= 0.5;
+                        else if(y[0] > 0.0) result[0] += 0.5;
+        }
+                        
+        if(x[1] > epsilon || abs(y[1]) > epsilon)
+        {
+                if(x[1] < 0.0 ^^ y[1] < 0.0)
+                {
+                        sign[1] = -1.0;
+                }
+
+                if(abs(y[1]) <= abs(x[1]))
+                {
+                        c[1] = abs(y[1] / x[1]);
+                        // Taylors series expansion for atan
+                        atan_c[1] += scale[1] * pow(c[1], float(1)) / float(1);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(3)) / float(3);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(5)) / float(5);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(7)) / float(7);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(9)) / float(9);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(11)) / float(11);
+                        scale[1] *= -1.0;
+
+                        result[1] = sign[1] * atan_c[1] / (2.0 * M_PI) + 0.5;
+                }
+                else
+                {
+                        c[1] = abs(x[1] / y[1]);
+
+                        // Taylors series expansion for atan
+                        atan_c[1] += scale[1] * pow(c[1], float(1)) / float(1);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(3)) / float(3);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(5)) / float(5);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(7)) / float(7);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(9)) / float(9);
+                        scale[1] *= -1.0;
+                        atan_c[1] += scale[1] * pow(c[1], float(11)) / float(11);
+                        scale[1] *= -1.0;
+
+                        result[1] = sign[1] * (M_PI / 2.0 - atan_c[1]) / (2.0 * M_PI) + 0.5;
+                }
+
+                if(x[1] < 0.0)
+                        if(y[1] < 0.0) result[1] -= 0.5;
+                        else if(y[1] > 0.0) result[1] += 0.5;
+        }
+        
+        color = result;
+        gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex;
+}