| |
| /* |
| ** 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. |
| */ |
| |
| |
| #ifdef GL_ES |
| precision mediump float; |
| #endif |
| varying vec4 color; |
| |
| /* This epsilon will work as long as the magnitude of the float is < 128. |
| * This can be seen by taking the spec relative mediump precision of 2^-10: |
| * 0.125 / 2^-10 = 128 |
| */ |
| #define ERROR_EPSILON (0.125) |
| |
| void main (void) |
| { |
| mat4 a = mat4( 1.0, 2.0, 3.0, 4.0, |
| 5.0, 6.0, 7.0, 8.0, |
| 9.0, 10.0, 11.0, 12.0, |
| 13.0, 14.0, 15.0, 16.0); |
| float gray,sum1=0.0,sum2=0.0,sum3=0.0,sum4=0.0; |
| int i; |
| |
| |
| sum1 += a[0][0]; |
| sum2 += a[1][0]; |
| sum3 += a[2][0]; |
| sum4 += a[3][0]; |
| |
| sum1 += a[0][1]; |
| sum2 += a[1][1]; |
| sum3 += a[2][1]; |
| sum4 += a[3][1]; |
| |
| sum1 += a[0][2]; |
| sum2 += a[1][2]; |
| sum3 += a[2][2]; |
| sum4 += a[3][2]; |
| |
| sum1 += a[0][3]; |
| sum2 += a[1][3]; |
| sum3 += a[2][3]; |
| sum4 += a[3][3]; |
| |
| if( ( sum1 > 10.0-ERROR_EPSILON && sum1 < 10.0+ERROR_EPSILON ) && |
| ( sum2 > 26.0-ERROR_EPSILON && sum2 < 26.0+ERROR_EPSILON) && |
| ( sum3 > 42.0-ERROR_EPSILON && sum3 < 42.0+ERROR_EPSILON) && |
| ( sum4 > 58.0-ERROR_EPSILON && sum4 < 58.0+ERROR_EPSILON) ) |
| gray=1.0; |
| else gray=0.0; |
| gl_FragColor = vec4(gray, gray, gray, 1.0); |
| } |