OLD | NEW |
(Empty) | |
| 1 |
| 2 /* |
| 3 ** Copyright (c) 2012 The Khronos Group Inc. |
| 4 ** |
| 5 ** Permission is hereby granted, free of charge, to any person obtaining a |
| 6 ** copy of this software and/or associated documentation files (the |
| 7 ** "Materials"), to deal in the Materials without restriction, including |
| 8 ** without limitation the rights to use, copy, modify, merge, publish, |
| 9 ** distribute, sublicense, and/or sell copies of the Materials, and to |
| 10 ** permit persons to whom the Materials are furnished to do so, subject to |
| 11 ** the following conditions: |
| 12 ** |
| 13 ** The above copyright notice and this permission notice shall be included |
| 14 ** in all copies or substantial portions of the Materials. |
| 15 ** |
| 16 ** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 17 ** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 18 ** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 19 ** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 20 ** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 21 ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 22 ** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS. |
| 23 */ |
| 24 |
| 25 |
| 26 attribute vec4 gtf_Vertex; |
| 27 attribute vec4 gtf_Color; |
| 28 uniform mat4 gtf_ModelViewProjectionMatrix; |
| 29 varying vec4 color; |
| 30 |
| 31 void main (void) |
| 32 { |
| 33 const float M_PI = 3.14159265358979323846; |
| 34 vec2 c = 4.0 * 2.0 * (gtf_Color.rg - 0.5); |
| 35 vec2 atan_c = vec2(0.0); |
| 36 vec2 scale = vec2(1.0); |
| 37 vec2 sign = vec2(1.0); |
| 38 vec4 result = vec4(0.0, 0.0, 0.0, 1.0); |
| 39 |
| 40 if(c[0] < 0.0) |
| 41 { |
| 42 sign[0] = -1.0; |
| 43 c[0] *= -1.0; |
| 44 } |
| 45 |
| 46 if(c[0] <= 1.0) |
| 47 { |
| 48 // Taylors series expansion for atan |
| 49 atan_c[0] += scale[0] * pow(c[0], float(1)) / float(1); |
| 50 scale[0] *= -1.0; |
| 51 atan_c[0] += scale[0] * pow(c[0], float(3)) / float(3); |
| 52 scale[0] *= -1.0; |
| 53 atan_c[0] += scale[0] * pow(c[0], float(5)) / float(5); |
| 54 scale[0] *= -1.0; |
| 55 atan_c[0] += scale[0] * pow(c[0], float(7)) / float(7); |
| 56 scale[0] *= -1.0; |
| 57 atan_c[0] += scale[0] * pow(c[0], float(9)) / float(9); |
| 58 scale[0] *= -1.0; |
| 59 atan_c[0] += scale[0] * pow(c[0], float(11)) / float(11); |
| 60 scale[0] *= -1.0; |
| 61 |
| 62 result[0] = sign[0] * atan_c[0] / M_PI + 0.5; |
| 63 } |
| 64 else |
| 65 { |
| 66 c[0] = 1.0 / c[0]; |
| 67 |
| 68 // Taylors series expansion for atan |
| 69 atan_c[0] += scale[0] * pow(c[0], float(1)) / float(1); |
| 70 scale[0] *= -1.0; |
| 71 atan_c[0] += scale[0] * pow(c[0], float(3)) / float(3); |
| 72 scale[0] *= -1.0; |
| 73 atan_c[0] += scale[0] * pow(c[0], float(5)) / float(5); |
| 74 scale[0] *= -1.0; |
| 75 atan_c[0] += scale[0] * pow(c[0], float(7)) / float(7); |
| 76 scale[0] *= -1.0; |
| 77 atan_c[0] += scale[0] * pow(c[0], float(9)) / float(9); |
| 78 scale[0] *= -1.0; |
| 79 atan_c[0] += scale[0] * pow(c[0], float(11)) / float(11); |
| 80 scale[0] *= -1.0; |
| 81 |
| 82 result[0] = sign[0] * (M_PI / 2.0 - atan_c[0]) / M_PI + 0.5; |
| 83 } |
| 84 |
| 85 |
| 86 if(c[1] < 0.0) |
| 87 { |
| 88 sign[1] = -1.0; |
| 89 c[1] *= -1.0; |
| 90 } |
| 91 |
| 92 if(c[1] <= 1.0) |
| 93 { |
| 94 // Taylors series expansion for atan |
| 95 atan_c[1] += scale[1] * pow(c[1], float(1)) / float(1); |
| 96 scale[1] *= -1.0; |
| 97 atan_c[1] += scale[1] * pow(c[1], float(3)) / float(3); |
| 98 scale[1] *= -1.0; |
| 99 atan_c[1] += scale[1] * pow(c[1], float(5)) / float(5); |
| 100 scale[1] *= -1.0; |
| 101 atan_c[1] += scale[1] * pow(c[1], float(7)) / float(7); |
| 102 scale[1] *= -1.0; |
| 103 atan_c[1] += scale[1] * pow(c[1], float(9)) / float(9); |
| 104 scale[1] *= -1.0; |
| 105 atan_c[1] += scale[1] * pow(c[1], float(11)) / float(11); |
| 106 scale[1] *= -1.0; |
| 107 |
| 108 result[1] = sign[1] * atan_c[1] / M_PI + 0.5; |
| 109 } |
| 110 else |
| 111 { |
| 112 c[1] = 1.0 / c[1]; |
| 113 |
| 114 // Taylors series expansion for atan |
| 115 atan_c[1] += scale[1] * pow(c[1], float(1)) / float(1); |
| 116 scale[1] *= -1.0; |
| 117 atan_c[1] += scale[1] * pow(c[1], float(3)) / float(3); |
| 118 scale[1] *= -1.0; |
| 119 atan_c[1] += scale[1] * pow(c[1], float(5)) / float(5); |
| 120 scale[1] *= -1.0; |
| 121 atan_c[1] += scale[1] * pow(c[1], float(7)) / float(7); |
| 122 scale[1] *= -1.0; |
| 123 atan_c[1] += scale[1] * pow(c[1], float(9)) / float(9); |
| 124 scale[1] *= -1.0; |
| 125 atan_c[1] += scale[1] * pow(c[1], float(11)) / float(11); |
| 126 scale[1] *= -1.0; |
| 127 |
| 128 result[1] = sign[1] * (M_PI / 2.0 - atan_c[1]) / M_PI + 0.5; |
| 129 } |
| 130 |
| 131 color = result; |
| 132 gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex; |
| 133 } |
OLD | NEW |