BMP Loading Questions, More OpenGL!!! :D

Code:

---

int LoadGLTextures()                                                                        // Load Bitmaps And Convert To Textures
{
        int Status=FALSE;                                                                        // Status Indicator

        AUX_RGBImageRec *TextureImage[2];                                        // Create Storage Space For The Texture

        memset(TextureImage,0,sizeof(void *)*1);                  // Set The Pointer To NULL

        // Load The Bitmap, Check For Errors, If Bitmap's Not Found Quit
        if (TextureImage[0]=LoadBMP("Data/NeHe.bmp"))
        {

                Status=TRUE;                                                                        // Set The Status To TRUE

                glGenTextures(1, &texture[0]);                                        // Create The Texture

                // Typical Texture Generation Using Data From The Bitmap
                glBindTexture(GL_TEXTURE_2D, texture[0]);
                glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);
                glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
                glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        }


        if (TextureImage[0])                                                                        // If Texture Exists
        {
                if (TextureImage[0]->data)                                                        // If Texture Image Exists
                {
                        free(TextureImage[0]->data);                                        // Free The Texture Image Memory
                }

                free(TextureImage[0]);                                                                // Free The Image Structure
        }

        // Load The Bitmap, Check For Errors, If Bitmap's Not Found Quit
        if (TextureImage[1]=LoadBMP("Data/NeHe1.bmp"))
        {

                Status=TRUE;                                                                        // Set The Status To TRUE

                glGenTextures(1, &texture[1]);                                        // Create The Texture

                // Typical Texture Generation Using Data From The Bitmap
                glBindTexture(GL_TEXTURE_2D, texture[1]);
                glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[1]->sizeX, TextureImage[1]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[1]->data);
                glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
                glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        }


        if (TextureImage[1])                                                                        // If Texture Exists
        {
                if (TextureImage[1]->data)                                                        // If Texture Image Exists
                {
                        free(TextureImage[1]->data);                                        // Free The Texture Image Memory
                }

                free(TextureImage[1]);                                                                // Free The Image Structure
        }

        return Status;                                                                                // Return The Status
}

---

Now you see, this code is cool and all, and it loads my textures, but........ Why would I need to modify the glGenTextures() function to generate more than 1 texture at a time....

Do I need to do this to allocate memory for each time I use this texture? Say 3 sides of my cube are one texture, and the other 3 are some other texture, do I need to generate 3 textures (for better memory allocation) Or is it save generating one texture for unlimited usage of the texture....

here's a good book on OpenGL, and its free to download too. Covers your question(s).

http://www.opengl.org/documentation/...1.0/index.html

Thanks :)

You must believe me I'm not asking anyone to do work for me, I have been studying this topic for a week :)

[EDIT]"no-one" posted while I was typing. i'll leave this here anyway though.

your code generates 1 texture, because your only loading 1 texture. if you were loading 3 textures, you would generate 3 textures.
My JPEG loading code (still applies):

Code:

---

void CreateTexture(UINT textureArray[], LPSTR strFileName, int textureID)
{
        if(!strFileName)                                                                       
                return;
       
        tImageJPG *pImage = LoadJPG(strFileName);                       


        if(pImage == NULL)                                                                       
                exit(0);
       
        glGenTextures(1, &textureArray[textureID]);
       
        glBindTexture(GL_TEXTURE_2D, textureArray[textureID]);
       
        gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB8, pImage->sizeX, pImage->sizeY, GL_RGB, GL_UNSIGNED_BYTE, pImage->data);
       
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_LINEAR);
       
        if (pImage)                                                                               
        {
                if (pImage->data)                                                       
                {
                        free(pImage->data);                                               
                }

                free(pImage);                                                               
        }
}

---

This code generates and loads 1 texture at a time. the texture is determined by the texture ID. your code is loading a hard-coded texture ID, so in your case, you would need to generate more than 1 to allow for more textureIDs.
If you don't understand what I'm trying to say, just give another post, and i'll try and elabourate a little more.

-psychopath

Lesse, since I'm implementing the texture in my program more than once, I should load it as much as I'm using it?

I have a Cube, 6 sides, 3 sides are the NeHe1.bmp (one i modified), and the other 3 are NeHe.bmp

Instead of generating 1 texture for each individual texture I should generate 3 because I'm using that many?

OR

I should use glGenTexture() ONCE for each Texture, not for as many times as I wish to implement it on my cube

one Texture ID per texture. not per use.

So my code is pretty much as optimized as it can be for pregenerating textures before the program actually starts, cool...


Question, what happens when I have 100 textures in my program, will this process still be as efficient?

however you go about it, you're still loading 100 textures, so no, I don't think it really matters, and it will have the same efficiency.

-psychopath

Ah, I found out why you would generate more than one texture per texture ID...

So you can add mip mapping, and other texture settings like that

Another Question, also if I have 100 different textures, is there any way to organize them into a specific file, and load them all at once?

You'd either have to make your own file format and loader or find some API to do that for you.

Oh I see, like alot of games have a .pak file

For instance

textures.pak
sound.pak
map.pak

I see.. I'll have to learn that one on my own i guess

I believe a lot of them are just implementations of zip compression with a different filename. I know the warcraft 3 files you can open in winrar after renaming them.

You could check out ZLIB.

http://www.gzip.org/zlib/