OpenGL: Render to FBO using multiple textures - c++

Question

I'm experimenting with a renderer. What I want is to write a color buffer and a normal buffer to two separate textures. I got that part figured out.
However, the color buffer is supposed to be a combination of two textures. This should do the trick:
glActiveTexture(GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
g_Tex->Bind();
glActiveTexture(GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
g_TexNormal->Bind();
g_Shader->Enable();
RenderScene();
g_Shader->Disable();
glActiveTexture(GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
And this is the fragment shader: (GLSL)
uniform sampler2D tex_diffuse;
uniform sampler2D tex_normal;
void main()
{
gl_FragColor = texture2D(tex_diffuse, gl_TexCoord[0].st);
//gl_FragColor = texture2D(tex_normal, gl_TexCoord[0].st);
}
However, the second texture is the same as the first! Whichever texture is attached to GL_TEXTURE0 is the one used for both samplers.
Initializing the FBO:
glGenFramebuffersEXT(1, &g_FBOColor);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, g_FBOColor);
glGenTextures(1, &g_FBOTexColor);
glBindTexture(GL_TEXTURE_2D, g_FBOTexColor);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, g_FBOTexColor, 0);
glGenTextures(1, &g_FBOTexNormal);
glBindTexture(GL_TEXTURE_2D, g_FBOTexNormal);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D, g_FBOTexNormal, 0);
glGenTextures(1, &g_FBOTexDepth);
glBindTexture(GL_TEXTURE_2D, g_FBOTexDepth);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, w, h, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, g_FBOTexDepth, 0);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
Complete render section:
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, g_FBOColor);
glPushAttrib(GL_VIEWPORT_BIT | GL_COLOR_BUFFER_BIT);
glViewport(
0, 0,
Window::GetSingleton()->GetWidth(), Window::GetSingleton()->GetHeight()
);
GLenum buffers[] = { GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT };
glDrawBuffers(2, buffers);
//glReadBuffer(GL_COLOR_ATTACHMENT0_EXT | GL_COLOR_ATTACHMENT1_EXT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glActiveTexture(GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
g_Tex->Bind();
glActiveTexture(GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
g_TexNormal->Bind();
g_Shader->Enable();
RenderScene();
g_Shader->Disable();
glActiveTexture(GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
glPopAttrib();
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
Thanks in advance.

Answer 1

Well I figured it out. :)
The reason my textures didn't work was because I didn't set up the uniform locations. Fixed code:
g_Shader->Enable();
glActiveTexture(GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
g_Tex->Bind();
glUniform1i(glGetUniformLocation(g_Shader->GetProgram(), "tex_diffuse"), 0);
glActiveTexture(GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
g_TexNormal->Bind();
glUniform1i(glGetUniformLocation(g_Shader->GetProgram(), "tex_normal"), 1);
RenderScene();
glActiveTexture(GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
g_Shader->Disable();