| |
| /* |
| ** 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 2 by 2 matrix with unique elements. |
| mat2 a = mat2(1.0, 2.0, // 1.0 4.0 |
| 4.0, 8.0); // 2.0 8.0 |
| |
| // Copy the matrix to another non-const matrix. |
| mat2 b = a; |
| |
| // Check each element of the copy. |
| bool elms = true; |
| if(b[0][0] != 1.0) elms = false; |
| if(b[0][1] != 2.0) elms = false; |
| if(b[1][0] != 4.0) elms = false; |
| if(b[1][1] != 8.0) elms = false; |
| |
| // Add up each row of the copy. |
| bool rows = true; |
| x = b[0][0] + b[1][0]; |
| if(x < 5.0-ERROR_EPSILON || x > 5.0+ERROR_EPSILON) rows = false; |
| x = b[0][1] + b[1][1]; |
| if(x < 10.0-ERROR_EPSILON || x > 10.0+ERROR_EPSILON) rows = false; |
| |
| // Add up each column of the copy. |
| bool cols = true; |
| x = b[0][0] + b[0][1]; |
| if(x < 3.0-ERROR_EPSILON || x > 3.0+ERROR_EPSILON) cols = false; |
| x = b[1][0] + b[1][1]; |
| if(x < 12.0-ERROR_EPSILON || x > 12.0+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); |
| } |
| |