I'm trying to show image using glTexImage2D, I work with MFC, Visual C 6.0.
Here the code:
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
/* enable 2D texture mapping */
glEnable( GL_TEXTURE_2D );
glTexImage2D(
GL_TEXTURE_2D, 0, GL_RGB,
800, 600,
0, GL_RGB, GL_UNSIGNED_BYTE, BitmapBits);
static float v0[3] = { 0.0, 0.0, 0.0 };
static float v1[3] = { 0.0, 1.0, 0.0 };
static float v2[3] = { 1.0, 1.0, 0.0 };
static float v3[3] = { 1.0, 0.0, 0.0 };
static float t0[2] = { 0.0, 0.0 };
static float t1[2] = { 0.0, 1.0 };
static float t2[2] = { 1.0, 1.0 };
static float t3[2] = { 1.0, 0.0 };
glBegin( GL_QUADS );
glTexCoord2f(0.0, 0.0);
glVertex3f(0.0, 0.0, 0.0);
glTexCoord2f(1.0, 0.0);
glVertex3f(1.0, 0.0, 0.0);
glTexCoord2f(1.0, 1.0);
glVertex3f(1.0, 1.0, 0.0);
glTexCoord2f(0.0, 1.0);
glVertex3f(0.0, 1.0, 0.0);
glEnd();
glDisable( GL_TEXTURE_2D );
I see only blue hue of the image. The loaded image BitmapBits is OK.
What can be the problem?
You probably want to use
GL_BGR_EXT
/GL_BGR
for format, notGL_RGB
:Or swap the bytes yourself before uploading.
Since you're using NPOT textures make sure to check for
GL_ARB_texture_non_power_of_two
or GL version >= 2.0.EDIT: Make sure you have
glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
before upload.