Opengl C++: texture code textures all models with the same texture - c++

Question

I created a class to hold my models information. I have to models rendering correctly and the textures properly wrapping, but for some reason if I have multiple models it will texture all of my models in just 1 texture as you can see in this image: http://imgur.com/d0glIwF
Any ideas why this might be happening?
This is my code:
struct BitMapFile
{
int sizeX;
int sizeY;
unsigned char *data;
};
// Routine to read a bitmap file.
// Works only for uncompressed bmp files of 24-bit color.
BitMapFile *getBMPData(string filename)
{
BitMapFile *bmp = new BitMapFile;
unsigned int size, offset, headerSize;
// Read input file name.
ifstream infile(filename.c_str(), ios::binary);
// Get the starting point of the image data.
infile.seekg(10);
infile.read((char *) &offset, 4);
// Get the header size of the bitmap.
infile.read((char *) &headerSize,4);
// Get width and height values in the bitmap header.
infile.seekg(18);
infile.read( (char *) &bmp->sizeX, 4);
infile.read( (char *) &bmp->sizeY, 4);
// Allocate buffer for the image.
size = bmp->sizeX * bmp->sizeY * 24;
bmp->data = new unsigned char[size];
// Read bitmap data.
infile.seekg(offset);
infile.read((char *) bmp->data , size);
// Reverse color from bgr to rgb.
int temp;
for (int i = 0; i < size; i += 3)
{
temp = bmp->data[i];
bmp->data[i] = bmp->data[i+2];
bmp->data[i+2] = temp;
}
return bmp;
}
class Model
{
public:
Model(string modelFilename, string textureFilename);
float getCenterX() { return m_CenterX; }
float getCenterY() { return m_CenterY; }
float getCenterZ() { return m_CenterZ; }
void SetCenterX(float x) { m_CenterX = x; }
void SetCenterY(float y) { m_CenterY = y; }
void SetCenterZ(float z) { m_CenterZ = z; }
void LoadTexture(string fileName);
//load model function
void Draw();
private:
float m_CenterX, m_CenterY, m_CenterZ, m_Width, m_Height, m_Depth;
string m_ModelFilename;
int m_Texture;
string m_TextureName;
};
Model::Model(string modelFilename, string textureFilename)
{
m_ModelFilename = modelFilename;
m_TextureName = textureFilename;
//load model function//
LoadTexture(m_TextureName);
}
void Model::LoadTexture(string TextureName)
{
// Local storage for bmp image data.
BitMapFile *image[1];
string filename = TextureName;
filename.append(".bmp");
// Load the texture.
image[0] = getBMPData(filename);
// Bind grass image to texture index[i].
glBindTexture(GL_TEXTURE_2D, m_Texture); //makes room for our texture
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, //always GL_TEXTURE_2D
0, //0 for now
GL_RGB, //format opengl uses to read textures
image[0]->sizeX, //width
image[0]->sizeY, //height
0, //the border of the image
GL_RGB, //GL_RGB because pixels are stored in RGB format
GL_UNSIGNED_BYTE, //GL_UNSIGNED_BYTE because pixels are stored as unsigned numbers
image[0]->data); //actual pixel data
}
void Model::Draw()
{
glPushMatrix();
glTranslatef(m_CenterX, m_CenterY, m_CenterZ);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, m_Texture);
glBegin(GL_TRIANGLES);
//my code for drawing the model to the screen. it isn't the problem so i removed it
glEnd();
glDisable(GL_TEXTURE_2D);
glPopMatrix();
}
Model model;
Model model1;
// Drawing routine.
void drawScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
model.SetCenterX(0);
model.SetCenterY(0);
model.SetCenterZ(12);
model.Draw();
model1.SetCenterX(12);
model1.SetCenterY(10);
model1.SetCenterZ(0);
model1.Draw();
glutSwapBuffers();
}
void setup(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
//model = Model("monkey.obj", "launch");
model = Model("cube.obj", "launch");
model1 = Model("cube.obj", "grass");
// Specify how texture values combine with current surface color values.
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
}
Thank you in advance.

Answer 1

The problem is that you're not creating a texture id. You can do that using the glGenTextures function. In your case I would put it at the beginning of the LoadTexture method - just ask it for 1 texture id and save what it gives you back into m_Texture.
Remember that, like everything you create using glGen*, it should also be deleted when you're done with it using glDelete* (glDeleteTextures in this case).
Also, consider moving to more modern OpenGL with shaders and vertex arrays. This is a very broad topic, unfortunately. There are lots of tutorials and books available, I learned from OpenGL Superbible, though I hear that some people don't like it very much...