I'm using FreeType in order to allow fonts to be use开发者_如何学运维d in OpenGL. However, I'm having a problem where I cannot change the font colour whenever I do texture mapping. No matter what I select using glColor3f it will just come out white. The texture works fine.
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
glColor3f(0.5,0.0,0.5);
glPushMatrix();
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_TEXTURE_2D);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glBindTexture(GL_TEXTURE_2D, texName);
glBegin(GL_POLYGON);
glTexCoord2f(0,1); glVertex2f(-16,-16);
glTexCoord2f(0,0); glVertex2f(-16,16);
glTexCoord2f(1,0); glVertex2f(16,16);
glTexCoord2f(1,1); glVertex2f(16,-16);
glEnd();
glDisable(GL_TEXTURE_2D);
glDisable(GL_BLEND);
glPopMatrix();
glColor3f(1,0,0);
print(our_font, -300+screenWidth/2.0, screenHeight/2.0, "fifty two - %7.2f", spin);
This is the problem code, I can confirm that drawing a polygon beneath this code will indeed make it red. The text is not changing to red though which it should; if you remove the texture mapping above it will turn red again, I can only think it is a problem with enabling and disabling and I've forgotten to do something...?
Fixed it. Just after I disabled texturing I forgot to set the environment back to modulate:
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
adding this after disabling texture/blending fixes the problem.
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