| |
| /* |
| ** 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 |
| |
| /* 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) |
| { |
| float x; |
| // Declare a constant 4 by 4 matrix with unique elements. |
| const 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); |
| |
| // Check each element. |
| bool elms = true; |
| if(a[0][0] != 1.0) elms = false; |
| if(a[0][1] != 2.0) elms = false; |
| if(a[0][2] != 3.0) elms = false; |
| if(a[0][3] != 4.0) elms = false; |
| if(a[1][0] != 5.0) elms = false; |
| if(a[1][1] != 6.0) elms = false; |
| if(a[1][2] != 7.0) elms = false; |
| if(a[1][3] != 8.0) elms = false; |
| if(a[2][0] != 9.0) elms = false; |
| if(a[2][1] != 10.0) elms = false; |
| if(a[2][2] != 11.0) elms = false; |
| if(a[2][3] != 12.0) elms = false; |
| if(a[3][0] != 13.0) elms = false; |
| if(a[3][1] != 14.0) elms = false; |
| if(a[3][2] != 15.0) elms = false; |
| if(a[3][3] != 16.0) elms = false; |
| |
| // Add up each row. |
| bool rows = true; |
| x = a[0][0] + a[1][0] + a[2][0] + a[3][0]; |
| if(x < 28.0-ERROR_EPSILON || x > 28.0+ERROR_EPSILON) rows = false; |
| x = a[0][1] + a[1][1] + a[2][1] + a[3][1]; |
| if(x < 32.0-ERROR_EPSILON || x > 32.0+ERROR_EPSILON) rows = false; |
| x = a[0][2] + a[1][2] + a[2][2] + a[3][2]; |
| if(x < 36.0-ERROR_EPSILON || x > 36.0+ERROR_EPSILON) rows = false; |
| x = a[0][3] + a[1][3] + a[2][3] + a[3][3]; |
| if(x < 40.0-ERROR_EPSILON || x > 40.0+ERROR_EPSILON) rows = false; |
| |
| // Add up each column of the copy. |
| bool cols = true; |
| x = a[0][0] + a[0][1] + a[0][2] + a[0][3]; |
| if(x < 10.0-ERROR_EPSILON || x > 10.0+ERROR_EPSILON) cols = false; |
| x = a[1][0] + a[1][1] + a[1][2] + a[1][3]; |
| if(x < 26.0-ERROR_EPSILON || x > 26.0+ERROR_EPSILON) cols = false; |
| x = a[2][0] + a[2][1] + a[2][2] + a[2][3]; |
| if(x < 42.0-ERROR_EPSILON || x > 42.0+ERROR_EPSILON) cols = false; |
| x = a[3][0] + a[3][1] + a[3][2] + a[3][3]; |
| if(x < 58.0-ERROR_EPSILON || x > 58.0+ERROR_EPSILON) cols = false; |
| |
| // Check if all of the operations were successful. |
| float gray = elms && rows && cols ? 1.0 : 0.0; |
| |
| // Assign the fragment color. |
| gl_FragColor = vec4(gray, gray, gray, 1.0); |
| } |
| |