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/*
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
*/
attribute vec4 gtf_Vertex;
uniform mat4 gtf_ModelViewProjectionMatrix;
varying vec4 color;
#define ERROR_EPSILON 0.1
void main (void)
{
float x;
// Declare a 4 by 4 matrix with unique elements.
mat4 a = mat4( 1.0, 2.0, 4.0, 8.0, // 1.0 16.0 256.0 4096.0
16.0, 32.0, 64.0, 128.0, // 2.0 32.0 512.0 8192.0
256.0, 512.0, 1024.0, 2048.0, // 4.0 64.0 1024.0 16384.0
4096.0, 8192.0, 16384.0, 32768.0); // 8.0 128.0 2048.0 32768.0
// 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] != 4.0) elms = false;
if(a[0][3] != 8.0) elms = false;
if(a[1][0] != 16.0) elms = false;
if(a[1][1] != 32.0) elms = false;
if(a[1][2] != 64.0) elms = false;
if(a[1][3] != 128.0) elms = false;
if(a[2][0] != 256.0) elms = false;
if(a[2][1] != 512.0) elms = false;
if(a[2][2] != 1024.0) elms = false;
if(a[2][3] != 2048.0) elms = false;
if(a[3][0] != 4096.0) elms = false;
if(a[3][1] != 8192.0) elms = false;
if(a[3][2] != 16384.0) elms = false;
if(a[3][3] != 32768.0) elms = false;
// Add up each row.
bool rows = true;
x = a[0][0] + a[1][0] + a[2][0] + a[3][0];
if(x < 4369.0-ERROR_EPSILON || x > 4369.0+ERROR_EPSILON) rows = false;
x = a[0][1] + a[1][1] + a[2][1] + a[3][1];
if(x < 8738.0-ERROR_EPSILON || x > 8738.0+ERROR_EPSILON) rows = false;
x = a[0][2] + a[1][2] + a[2][2] + a[3][2];
if(x < 17476.0-ERROR_EPSILON || x > 17476.0+ERROR_EPSILON) rows = false;
x = a[0][3] + a[1][3] + a[2][3] + a[3][3];
if(x < 34952.0-ERROR_EPSILON || x > 34952.0+ERROR_EPSILON) rows = false;
// Add up each column.
bool cols = true;
x = a[0][0] + a[0][1] + a[0][2] + a[0][3];
if(x < 15.0-ERROR_EPSILON || x > 15.0+ERROR_EPSILON) cols = false;
x = a[1][0] + a[1][1] + a[1][2] + a[1][3];
if(x < 240.0-ERROR_EPSILON || x > 240.0+ERROR_EPSILON) cols = false;
x = a[2][0] + a[2][1] + a[2][2] + a[2][3];
if(x < 3840.0-ERROR_EPSILON || x > 3840.0+ERROR_EPSILON) cols = false;
x = a[3][0] + a[3][1] + a[3][2] + a[3][3];
if(x < 61440.0-ERROR_EPSILON || x > 61440.0+ERROR_EPSILON) cols = false;
// Check if all of the operations were successful.
float gray = elms && rows && cols ? 1.0 : 0.0;
// Assign the varying variable color.
color = vec4(gray, gray, gray, 1.0);
// Transform the vertex position.
gl_Position = gtf_ModelViewProjectionMatrix * gtf_Vertex;
}
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