/**
* @brief Gets some information about the OpenGL window.
*
* @return 0 on success.
*/
static int gl_getGLInfo (void)
{
int doublebuf;
SDL_GL_GetAttribute( SDL_GL_RED_SIZE, &gl_screen.r );
SDL_GL_GetAttribute( SDL_GL_GREEN_SIZE, &gl_screen.g );
SDL_GL_GetAttribute( SDL_GL_BLUE_SIZE, &gl_screen.b );
SDL_GL_GetAttribute( SDL_GL_ALPHA_SIZE, &gl_screen.a );
SDL_GL_GetAttribute( SDL_GL_DOUBLEBUFFER, &doublebuf );
SDL_GL_GetAttribute( SDL_GL_MULTISAMPLESAMPLES, &gl_screen.fsaa );
if (doublebuf)
gl_screen.flags |= OPENGL_DOUBLEBUF;
/* Calculate real depth. */
gl_screen.depth = gl_screen.r + gl_screen.g + gl_screen.b + gl_screen.a;
/* Texture information */
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &gl_screen.tex_max);
glGetIntegerv(GL_MAX_TEXTURE_UNITS, &gl_screen.multitex_max);
/* Debug happiness */
DEBUG("OpenGL Window Created: %dx%d@%dbpp %s", SCREEN_W, SCREEN_H, gl_screen.depth,
gl_has(OPENGL_FULLSCREEN)?"fullscreen":"window");
DEBUG("r: %d, g: %d, b: %d, a: %d, db: %s, fsaa: %d, tex: %d",
gl_screen.r, gl_screen.g, gl_screen.b, gl_screen.a,
gl_has(OPENGL_DOUBLEBUF) ? "yes" : "no",
gl_screen.fsaa, gl_screen.tex_max);
DEBUG("vsync: %s, vbo: %s, mm: %s, compress: %s, npot: %s",
gl_has(OPENGL_VSYNC) ? "yes" : "no",
gl_vboIsHW() ? "yes" : "no",
gl_texHasMipmaps() ? "yes" : "no",
gl_texHasCompress() ? "yes" : "no",
gl_needPOT() ? "no" : "yes" );
DEBUG("Renderer: %s", glGetString(GL_RENDERER));
DEBUG("Version: %s", glGetString(GL_VERSION));
/* Now check for things that can be bad. */
if (gl_screen.multitex_max < OPENGL_REQ_MULTITEX)
WARN("Missing texture units (%d required, %d found)",
OPENGL_REQ_MULTITEX, gl_screen.multitex_max );
if ((conf.fsaa > 1) && (gl_screen.fsaa != conf.fsaa))
WARN("Unable to get requested FSAA level (%d requested, got %d)",
conf.fsaa, gl_screen.fsaa );
return 0;
}
/**
* @brief Loads a surface into an opengl texture.
*
* @param surface Surface to load into a texture.
* @param flags Flags to use.
* @param[out] rw Real width of the texture.
* @param[out] rh Real height of the texture.
* @return The opengl texture id.
*/
static GLuint gl_loadSurface( SDL_Surface* surface, int *rw, int *rh, unsigned int flags, int freesur )
{
GLuint texture;
GLfloat param;
/* Prepare the surface. */
surface = gl_prepareSurface( surface );
if (rw != NULL)
(*rw) = surface->w;
if (rh != NULL)
(*rh) = surface->h;
/* opengl texture binding */
glGenTextures( 1, &texture ); /* Creates the texture */
glBindTexture( GL_TEXTURE_2D, texture ); /* Loads the texture */
/* Filtering, LINEAR is better for scaling, nearest looks nicer, LINEAR
* also seems to create a bit of artifacts around the edges */
if ((gl_screen.scale != 1.) || (flags & OPENGL_TEX_MIPMAPS)) {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
else {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
}
/* Always wrap just in case. */
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
/* now lead the texture data up */
SDL_LockSurface( surface );
if (gl_texHasCompress()) {
glTexImage2D( GL_TEXTURE_2D, 0, GL_COMPRESSED_RGBA,
surface->w, surface->h, 0, GL_RGBA,
GL_UNSIGNED_BYTE, surface->pixels );
}
else {
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA,
surface->w, surface->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, surface->pixels );
}
SDL_UnlockSurface( surface );
/* Create mipmaps. */
if ((flags & OPENGL_TEX_MIPMAPS) && gl_texHasMipmaps()) {
/* Do fancy stuff. */
if (gl_hasExt("GL_EXT_texture_filter_anisotropic")) {
glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, ¶m);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, param);
}
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 9);
/* Now generate the mipmaps. */
nglGenerateMipmap(GL_TEXTURE_2D);
}
/* cleanup */
if (freesur)
SDL_FreeSurface( surface );
gl_checkErr();
return texture;
}
