How to update a uniform variable in GLSL
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by paj777
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Published on 2010-03-25T08:46:37Z
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2010/03/25
8:53 UTC
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Hi All,
I am trying to get update the eye position in my shader from my appliaction but I keep getting error 1281 when I attempt this. I have no problems after the initialization just when i subsequently try to update the values. Here is my code:
void GraphicsObject::SendShadersDDS(char vertFile [], char fragFile [], char filename []) {
char *vs = NULL,*fs = NULL;
vert = glCreateShader(GL_VERTEX_SHADER);
frag = glCreateShader(GL_FRAGMENT_SHADER);
vs = textFileRead(vertFile);
fs = textFileRead(fragFile);
const char * ff = fs;
const char * vv = vs;
glShaderSource(vert, 1, &vv, NULL);
glShaderSource(frag, 1, &ff, NULL);
free(vs); free(fs);
glCompileShader(vert);
glCompileShader(frag);
program = glCreateProgram();
glAttachShader(program, frag);
glAttachShader(program, vert);
glLinkProgram(program);
glUseProgram(program);
LoadCubeTexture(filename, compressedTexture);
GLint location = glGetUniformLocation(program, "tex");
glUniform1i(location, 0);
glActiveTexture(GL_TEXTURE0);
EyePos = glGetUniformLocation(program, "EyePosition");
glUniform4f(EyePos, EyePosition.X(),EyePosition.Y(),
EyePosition.Z(), 1.0);
DWORD bob = glGetError();
//All is fine here
glEnable(GL_DEPTH_TEST);
}
And here's the function I call to update the eye position:
void GraphicsObject::UpdateEyePosition(Vector3d& eyePosition){
glUniform4f(EyePos, eyePosition.X(),eyePosition.Y(),
eyePosition.Z(), 1.0);
DWORD bob = glGetError();
//bob equals 1281 after this call
}
I've tried a few ways now of updating the variable and this is the latest incarnation, thanks for viewing, all comments welcome.
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