Texture Coordinate Generation

Rather than having to explicitly provide a texture coordinate for each vertex, we can use texture coordinate generation (texgen) functions to have OpenGL automatically compute texture coordinates.

This uses the function glTexGen, and the glEnable modes GL_TEXTURE_GEN_S & GL_TEXTURE_GEN_T.

planeCoefficients = [ 1, 0, 0, 0 ]
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR)
glTexGenfv(GL_S, GL_OBJECT_PLANE, planeCoefficients)
glEnable(GL_TEXTURE_GEN_S)

glBegin(GL_QUADS)
glVertex3f(-3.25, -1, 0)
glVertex3f(-1.25, -1, 0)
glVertex3f(-1.25, 1, 0)
glVertex3f(-3.25, 1, 0)
glEnd()

Example: contour.cpp