OpenGL - 'glTexSubImage3D': identifier not found - c++

Question

Problem: I've been trying to figure out this error in OpenGL that I keep getting with glTexSubImage3D. VS2010 throws the error: glTexSubImage3D: identifier not found
Usage: I am trying to create a 3D texture with ten slices (images) placed along the z-dimension. It is similar to the question in this post: C++ - place multiple images in an array pointer
However, I have been trying to use glTexSubImage3D in order to avoid these access violation errors.
I have included glext.h in my project and since, glTexImage3D is not part of OpenGL libraries yet, I have used the function pointer PFNGLTEXIMAGE3DPROC glTexImage3D as provided for use here: http://content.gpwiki.org/index.php/OpenGL:Tutorials:3D_Textures
Code:
I have been following NeHe's Texture Mapping tutorial and volume rendering tutorial present here: http://www.codeproject.com/Articles/352270/Getting-started-with-Volume-Rendering?msg=4729498
GLuint m_nTexId;
unsigned char *tex;
int h = 1024;
int w = 256;
int slices = 10;
PFNGLTEXIMAGE3DPROC glTexImage3D = (PFNGLTEXIMAGE3DPROC) wglGetProcAddress("glTexImage3D");
int LoadGLTextures()
{
glGenTextures(1,(GLuint*)&m_nTexId );
if(m_nTexId == 0)
return false;
glBindTexture( GL_TEXTURE_3D, m_nTexId );
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_BORDER);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, w, h , slices, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
tex = (unsigned char *)SOIL_load_image("Data/PA_170090.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 0, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char*) SOIL_load_image("Data/PA_170091.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 1, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char *)SOIL_load_image("Data/PA_170092.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 2, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char *)SOIL_load_image("Data/PA_170093.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 3, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char *)SOIL_load_image("Data/PA_170094.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 4, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char *)SOIL_load_image("Data/PA_170095.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 5, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char*) SOIL_load_image("Data/PA_170096.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 6, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char*) SOIL_load_image("Data/PA_170097.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 7, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char*) SOIL_load_image("Data/PA_170098.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 8, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
tex = (unsigned char*) SOIL_load_image("Data/PA_170099.png", &w, &h, NULL, 0);
glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 9, h, w, 1, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) tex);
//glBindTexture( GL_TEXTURE_3D, 0 );
return true;
}

Answer 1

The problem is the same as you had when you originally tried to use glTexImage3D (...). Namely, 3D textures are a feature of OpenGL 1.2 and Windows only gives you OpenGL 1.1 without run-time extension.
You need to load the glTexSubImage3D (...) function the same as you did glTexImage3D (...).
PFNGLTEXSUBIMAGE3DPROC glTexSubImage3D =
(PFNGLTEXSUBIMAGE3DPROC) wglGetProcAddress("glTexSubImage3D");