static GLint win = 0;
static GLboolean anim = GL_TRUE;
static GLfloat xRot = 0.0f, yRot = 0.0f;
+static GLint WinSize[2];
+static GLint WinSizeUniform = -1;
static void
Redisplay(void)
{
+ glUniform2iv(WinSizeUniform, 1, WinSize);
+
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
static void
Reshape(int width, int height)
{
+ WinSize[0] = width;
+ WinSize[1] = height;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
Init(void)
{
static const char *fragShaderText =
+ "uniform ivec2 WinSize; \n"
"void main() {\n"
- " gl_FragColor = abs(dFdy(gl_TexCoord[0])) * 50.0;\n"
+ " vec2 d = dFdy(gl_TexCoord[0].xy) * vec2(WinSize); \n"
+ " gl_FragColor = vec4(d.x, d.y, 0.0, 1.0);\n"
" // gl_FragColor = gl_TexCoord[0];\n"
"}\n";
static const char *vertShaderText =
program = LinkShaders(vertShader, fragShader);
glUseProgram(program);
+ WinSizeUniform = glGetUniformLocation(program, "WinSize");
/*assert(glGetError() == 0);*/
int
main(int argc, char *argv[])
{
+ WinSize[0] = WinSize[1] = 200;
+
glutInit(&argc, argv);
- glutInitWindowSize(200, 200);
+ glutInitWindowSize(WinSize[0], WinSize[1]);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
win = glutCreateWindow(argv[0]);
glewInit();