Im using this code to auto-generate coords for texture mapping, but the textures are drawn inverted/flipped why?
void draw_simple_quad(int QUAD_ID)
{
glBindTexture(GL_TEXTURE_2D, texture[Terrain[QUAD_ID].texture_id]);
GLfloat tPlane = {1.0/MAP_SIZE, 0, 0, 0};
GLfloat sPlane = {0,0,1.0/MAP_SIZE, 0};
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);glTexGenfv(GL_S, GL_OBJECT_PLANE,sPlane);
glTexGenfv(GL_T, GL_OBJECT_PLANE, tPlane);glBegin(GL_TRIANGLES);
glTexCoord2f(0,0);
glVertex3f(Terrain[QUAD_ID].vertices_x1[0],
Terrain[QUAD_ID].vertices_y1[0],
Terrain[QUAD_ID].vertices_z1[0]);
glTexCoord2f(1,0);
glVertex3f(Terrain[QUAD_ID].vertices_x2[0],
Terrain[QUAD_ID].vertices_y2[0],
Terrain[QUAD_ID].vertices_z2[0]);
glTexCoord2f(1,1);
glVertex3f(Terrain[QUAD_ID].vertices_x3[0],
Terrain[QUAD_ID].vertices_y3[0],
Terrain[QUAD_ID].vertices_z3[0]);
glTexCoord2f(0,1);
glVertex3f(Terrain[QUAD_ID].vertices_x4[0],
Terrain[QUAD_ID].vertices_y4[0],
Terrain[QUAD_ID].vertices_z4[0]);
glTexCoord2f(0,0);
glVertex3f(Terrain[QUAD_ID].vertices_x5[0],
Terrain[QUAD_ID].vertices_y5[0],
Terrain[QUAD_ID].vertices_z5[0]);
glTexCoord2f(1,1);
glVertex3f(Terrain[QUAD_ID].vertices_x6[0],
Terrain[QUAD_ID].vertices_y6[0],
Terrain[QUAD_ID].vertices_z6[0]);
glEnd();
}