void texture::submit( int format, bool build_mip_maps )
{
std::vector<unsigned char> pixels = ( format == GL_RGBA ? rgba_data() : rgb_data() );
// Set unpack alignment to one byte
GLint UnpackAlignment;
glGetIntegerv( GL_UNPACK_ALIGNMENT, &UnpackAlignment );
glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
// Submit decoded data to texture
GLint ret;
if( build_mip_maps )
ret = gluBuild2DMipmaps(GL_TEXTURE_2D, format, w, h, format, GL_UNSIGNED_BYTE, pixels.data() );
else
glTexImage2D(GL_TEXTURE_2D, 0 /*LOD*/, format, w, h, 0 /*border*/, format, GL_UNSIGNED_BYTE, pixels.data() );
// Restore old unpack alignment
glPixelStorei( GL_UNPACK_ALIGNMENT, UnpackAlignment );
}
//saves the given SDL structure into a given filename.
void save_image(surface surf, const std::string &filename)
{
//opens the actual file
const util::scoped_FILE file(fopen(filename.c_str(),"wb"));
//initializes PNG write structures
//TODO: review whether providing NULL error handlers is something
//sensible
png_struct* png_ptr = png_create_write_struct
(PNG_LIBPNG_VER_STRING, reinterpret_cast<png_voidp>(png_voidp_NULL),
png_error_ptr_NULL, png_error_ptr_NULL);
if(!png_ptr)
throw exploder_failure("Unable to initialize the png write structure");
png_info* info_ptr = png_create_info_struct(png_ptr);
if(!info_ptr) {
png_destroy_write_struct(&png_ptr,
static_cast<png_infopp>(NULL));
throw exploder_failure("Unable to initialize the png info structure");
}
//instructs the PNG library to use the open file
png_init_io(png_ptr, file);
//sets compression level to the maximum
png_set_compression_level(png_ptr,
Z_BEST_COMPRESSION);
//configures the header
png_set_IHDR(png_ptr, info_ptr, surf->w, surf->h,
8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
//puts the actual image data in the row_pointers array
png_byte **row_pointers = new png_byte *[surf->h];
surface_lock lock(surf);
//converts the data to the RGBA format. We cannot pass SDL data
//directly to the png lib, even if we know its pixel format, because of
//endianness problems.
util::scoped_array<rgba> rgba_data(new rgba[surf->w * surf->h]);
Uint32 *surf_data = lock.pixels();
int pos = 0;
for(int y = 0; y < surf->h; ++y) {
row_pointers[y] = reinterpret_cast<png_byte*>(rgba_data + pos);
for(int x = 0; x < surf->w; ++x) {
Uint8 red, green, blue, alpha;
SDL_GetRGBA(*surf_data, surf->format, &red, &green, &blue, &alpha);
rgba_data[pos].r = red;
rgba_data[pos].g = green;
rgba_data[pos].b = blue;
rgba_data[pos].a = alpha;
pos++;
surf_data++;
}
}
png_set_rows(png_ptr, info_ptr, row_pointers);
//writes the actual image data
png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
//cleans everything
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
delete [] row_pointers;
}
