OPENGL how to load a texture with Alpha Channel

[Cydriic]

Hi Everyone,


I'm trying to load a Quad with a Monster Image on it that will always face the Camera, a la Doom 2.

Now I don't know how to load an image with an Alpha part on it.

In 2D using SDL I always used tga files.


Here is my LoadTexture functions.

Does anyone have an idea?

Thanks a lot.


AUX_RGBImageRec *LoadBMP(char *Filename) // Loads A Bitmap Image
{

FILE *File=NULL; // File Handle

if (!Filename) // Make Sure A Filename Was Given
{
return NULL; // If Not Return NULL
}

File=fopen(Filename,"r"); // Check To See If The File Exists

if (File) // Does The File Exist?
{
fclose(File); // Close The Handle
return auxDIBImageLoad(Filename); // Load The Bitmap And Return A Pointer
}

return NULL; // If Load Failed Return NULL
}

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

AUX_RGBImageRec* TextureImage[12]; // Create Storage Space For The Texture

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

//TEXTURE 0

// Load The Bitmap, Check For Errors, If Bitmap's Not Found Quit
if (TextureImage[0]=LoadBMP("Data/Grass00.bmp"))
{
Status=TRUE; // Set The Status To TRUE

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

// Create Nearest Filtered Texture
glBindTexture(GL_TEXTURE_2D, texture[0]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);


}
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
}

return TRUE;

}

[ne555]

https://www.khronos.org/opengles/sdk/1.1/docs/man/glTexEnv.xml
GL_DECAL

[10X9216C]

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

Think that 1 is suppose to be 12, but you can default initialize the array with zero. So you don't have to worry about the number in 2 places, and create an error like you just did.

AUX_RGBImageRec* TextureImage[12] = {}

http://ideone.com/qHdxbi