What is the routine of loading a BMP in SDL for OpenGL textures?

SDL Development
1

Hi,
What is the routine of loading a BMP in SDL for OpenGL textures? Is
it going to be like this?

// create the memory block to put the BMP in
SDL_Surface *image;

// load the BMP from “file_name” into the “image” memory area
image = SDL_LoadBMP(file_name);

// many OpenGL image enviroment settings are here
…
…
…

// main function to setup the texture in OpenGL
glTexImage2D(GL_TEXTURE_2D, 0, image->format->BitsPerPixel, image->w,
image->h, 0, [an opengl format], GL_UNSIGNED_BYTE, image->pixels);

// free the memory used for loading the BMP file
free(image);

Thanks in advance for any helpful replies.

Jack______________________________________________________________________
Post your free ad now! http://personals.yahoo.ca

2

[…code…]

Yeah, for OpenGL 1.2 and up, that might work most of the time. Another
method is to create a surface of a format you know OpenGL supports,
and blit the loaded image into it, to convert it. That’s simple and
safe, but obviously has some load time cost.

//David Olofson - Programmer, Composer, Open Source Advocate

.- The Return of Audiality! --------------------------------.
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— http://olofson.net — http://www.reologica.se —On Saturday 08 March 2003 20.22, Jack Chen wrote:

Hi,
What is the routine of loading a BMP in SDL for OpenGL
textures? Is it going to be like this?

3

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Hi,
What is the routine of loading a BMP in SDL for OpenGL textures? Is
it going to be like this?

[snip]

// free the memory used for loading the BMP file
free(image);

You must use SDL_FreeSurface here instead of plain free(). Also, I’d use
SDL_ConvertSurface to convert your bitmap into a format you know OpenGL
supports. For example, the current code wouldn’t work with palette bitmaps.

cu,
Nicolai

Thanks in advance for any helpful replies.

Jack
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-----END PGP SIGNATURE-----On Saturday 08 March 2003 20:22, Jack Chen wrote:

4

Hi,
What is the routine of loading a BMP in SDL for OpenGL textures? Is
it going to be like this?

By the way, in the SDL source archive in the test/testgl.c file there’s a
set of routines for loading and displaying images with OpenGL. The test
programs and all the code in them are in the public domain.

See ya,
-Sam Lantinga, Software Engineer, Blizzard Entertainment