I am having a little trouble getting my values to output correctly. For some reason my output is all white regardless of the fragment shader code. If I do a readpixels I get (1.0, 1.0, 1.0, 1.0) for each pixel.
my fragment shader looks like this:
(I know it doesn’t do much but it’s only to see if it’s writing correctly.)
void shader(in float2 texCoord: TEXCOORD0,
out float4 color : COLOR)
{
color.r = 1.0f;
color.g = 0.0f;
color.b = 0.0f;
color.a = 0.0f;
}
Theoretically this output should be all red right? But for some reason it is white.
I am not getting any Cg errors or OpenGL errors. I have a valid context, profile, program, etc. My draw function looks like this:
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear screen and depth buffer
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
bool drawError(false), readError(false);
const unsigned char *cgExt;
cgExt = glGetString(GL_EXTENSIONS);
fprintf(stderr, "%s
", cgExt);
cgGLEnableProfile(fragmentProfile);
cgErrorCallback();
cgGLBindProgram(fragmentProgram);
cgErrorCallback();
cgGLEnableTextureParameter(baseTexture);
cgErrorCallback();
glPushMatrix();
//glColor3f(1.0, 0.0, 0.0);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex2f(0, 0);
glTexCoord2f(float(size), 0); glVertex2f(float(size), 0);
glTexCoord2f(float(size), float(size)); glVertex2f(float(size), float(size));
glTexCoord2f(0, float(size)); glVertex2f(0, float(size));
glEnd();
glPopMatrix();
if(PrintGLerror())
drawError = true;
glReadPixels(0,0, size, size, GL_RGBA, GL_FLOAT, dataOut);
if(PrintGLerror())
readError = true;
cgGLDisableProfile(fragmentProfile);
cgGLDisableTextureParameter(baseTexture);
SwapBuffers(hDC);
if I uncomment the glColor3f and comment out fragment stuff I get correct rendering of a red quad. I have written fragment shaders successfully before and it’s hard for me to see the difference with what I have here and what has worked in the past.
Any help would be greatly appreciated.
thanks.
This is the second rewrite to get around this problem, but so far it has failed. I’m pretty stumped.