/**
* @brief Generates an filled circle texture.
*
* @param radius Radius of the circle to generate.
* @return The tetxure containing the generated circle.
*/
static glTexture *gl_genCircle( int radius )
{
int i,j,k, n,m;
SDL_Surface *sur;
uint8_t *pix, *buf;
int h, w;
double a;
char name[PATH_MAX];
/* Calculate parameters. */
w = 2*radius+1;
h = 2*radius+1;
/* Create the surface. */
sur = SDL_CreateRGBSurface( SDL_SWSURFACE, w, h, 32, RGBAMASK );
pix = sur->pixels;
/* Generate the circle. */
SDL_LockSurface( sur );
/* Create temporary buffer to draw circle in. */
k = 3;
buf = malloc( (h*k) * (w*k) );
for (i=0; i<k*h; i++) {
for (j=0; j<k*w; j++) {
if (pow2(i-k*radius)+pow2(j-k*radius) < pow2(k*radius))
buf[ i*k*w + j] = 0xFF;
}
}
/* Draw the circle with filter. */
for (i=0; i<h; i++) {
for (j=0; j<w; j++) {
/* Calculate blur. */
a = 0.;
for (n=0; n<k; n++)
for (m=0; m<k; m++)
a += buf[ (i*k+n)*k*w + (j*k+m) ];
a /= k*k;
/* Set pixel. */
pix[i*sur->pitch + j*4 + 0] = 0xFF;
pix[i*sur->pitch + j*4 + 1] = 0xFF;
pix[i*sur->pitch + j*4 + 2] = 0xFF;
pix[i*sur->pitch + j*4 + 3] = (uint8_t)a;
}
}
/* Clean up. */
free(buf);
SDL_UnlockSurface( sur );
/* Return texture. */
nsnprintf( name, sizeof(name), "gencircle%d", radius );
return gl_loadImagePad( name, sur, OPENGL_TEX_MIPMAPS, sur->w, sur->h, 1, 1, 1 );
}
/**
* @brief Loads the SDL_Surface to a glTexture.
*
* @param surface Surface to load.
* @param flags Flags to use.
* @return The glTexture for surface.
*/
glTexture* gl_loadImage( SDL_Surface* surface, unsigned int flags )
{
return gl_loadImagePad( NULL, surface, flags, surface->w, surface->h, 1, 1, 1 );
}
/**
* @brief Wrapper for gl_loadImagePad that includes transparency mapping.
*
* @param name Name to load with.
* @param surface Surface to load.
* @param rw RWops containing data to hash.
* @param flags Flags to use.
* @param w Non-padded width.
* @param h Non-padded height.
* @param sx X sprites.
* @param sy Y sprites.
* @param freesur Whether or not to free the surface.
* @return The glTexture for surface.
*/
glTexture* gl_loadImagePadTrans( const char *name, SDL_Surface* surface, SDL_RWops *rw,
unsigned int flags, int w, int h, int sx, int sy, int freesur )
{
glTexture *texture;
int i, filesize;
size_t cachesize, pngsize;
uint8_t *trans;
char *cachefile, *data;
char digest[33];
md5_state_t md5;
md5_byte_t *md5val;
if (name != NULL) {
texture = gl_texExists( name );
if (texture != NULL)
return texture;
}
if (flags & OPENGL_TEX_MAPTRANS)
flags ^= OPENGL_TEX_MAPTRANS;
/* Appropriate size for the transparency map, see SDL_MapTrans */
cachesize = gl_transSize(w, h);
cachefile = NULL;
trans = NULL;
if (rw != NULL) {
md5val = malloc(16);
md5_init(&md5);
pngsize = SDL_RWseek( rw, 0, SEEK_END );
SDL_RWseek( rw, 0, SEEK_SET );
data = malloc(pngsize);
if (data == NULL)
WARN("Out of memory!");
else {
SDL_RWread( rw, data, pngsize, 1 );
md5_append( &md5, (md5_byte_t*)data, pngsize );
free(data);
}
md5_finish( &md5, md5val );
for (i=0; i<16; i++)
nsnprintf( &digest[i * 2], 3, "%02x", md5val[i] );
free(md5val);
cachefile = malloc( PATH_MAX );
nsnprintf( cachefile, PATH_MAX, "%scollisions/%s",
nfile_cachePath(), digest );
/* Attempt to find a cached transparency map. */
if (nfile_fileExists(cachefile)) {
trans = (uint8_t*)nfile_readFile( &filesize, cachefile );
/* Consider cached data invalid if the length doesn't match. */
if (trans != NULL && cachesize != (unsigned int)filesize) {
free(trans);
trans = NULL;
}
/* Cached data matches, no need to overwrite. */
else {
free(cachefile);
cachefile = NULL;
}
}
}
else {
/* We could hash raw pixel data here, but that's slower than just
* generating the map from scratch.
*/
WARN("Texture '%s' has no RWops", name);
}
if (trans == NULL) {
SDL_LockSurface(surface);
trans = SDL_MapTrans( surface, w, h );
SDL_UnlockSurface(surface);
if (cachefile != NULL) {
/* Cache newly-generated transparency map. */
nfile_dirMakeExist( "%s/collisions/", nfile_cachePath() );
nfile_writeFile( (char*)trans, cachesize, cachefile );
free(cachefile);
}
}
texture = gl_loadImagePad( name, surface, flags, w, h, sx, sy, freesur );
texture->trans = trans;
return texture;
}
