int Graph_FillAlpha( LCUI_Graph *graph, uchar_t alpha )
{
int x, y;
LCUI_Rect rect;
LCUI_ARGB *pixel, *pixel_row;
Graph_GetValidRect( graph, &rect );
graph = Graph_GetQuote( graph );
if( !Graph_IsValid(graph) ) {
return -1;
}
if( !Graph_HasAlpha(graph) ) {
return -2;
}
pixel_row = graph->argb + rect.y*graph->w + rect.x;
for(y=0; y<rect.h; ++y) {
pixel = pixel_row;
for( x=0; x<rect.w; ++x ) {
pixel->alpha = alpha;
++pixel;
}
pixel_row += graph->w;
}
return 0;
}
int Graph_WritePNG( const char *file_name, const LCUI_Graph *graph )
{
#ifdef USE_LIBPNG
FILE *fp;
LCUI_Rect rect;
png_byte color_type;
png_structp png_ptr;
png_infop info_ptr;
png_bytep *row_pointers;
int x, y, row_size;
if( !Graph_IsValid( graph ) ) {
_DEBUG_MSG( "graph is not valid\n" );
return -1;
}
/* create file */
fp = fopen( file_name, "wb" );
if( !fp ) {
_DEBUG_MSG( "file %s could not be opened for writing\n", file_name );
return -1;
}
/* initialize stuff */
png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );
if( !png_ptr ) {
fclose( fp );
_DEBUG_MSG( "png_create_write_struct failed\n" );
return -1;
}
info_ptr = png_create_info_struct( png_ptr );
if( !info_ptr ) {
fclose( fp );
_DEBUG_MSG( "png_create_info_struct failed\n" );
png_destroy_write_struct( &png_ptr, &info_ptr );
return -1;
}
if( setjmp( png_jmpbuf( png_ptr ) ) ) {
fclose( fp );
_DEBUG_MSG( "error during init_io\n" );
png_destroy_write_struct( &png_ptr, &info_ptr );
return -1;
}
png_init_io( png_ptr, fp );
if( Graph_HasAlpha( graph ) ) {
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
} else {
color_type = PNG_COLOR_TYPE_RGB;
}
/* write header */
png_set_IHDR( png_ptr, info_ptr, graph->w, graph->h,
8, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE );
png_write_info( png_ptr, info_ptr );
/* write bytes */
Graph_GetValidRect( graph, &rect );
graph = Graph_GetQuote( graph );
if( graph->color_type == COLOR_TYPE_ARGB ) {
LCUI_ARGB *px_ptr, *px_row_ptr;
row_size = png_get_rowbytes( png_ptr, info_ptr );
px_row_ptr = graph->argb + rect.top * graph->width + rect.left;
row_pointers = (png_bytep*)malloc( rect.height*sizeof( png_bytep ) );
for( y = 0; y < rect.height; ++y ) {
row_pointers[y] = png_malloc( png_ptr, row_size );
px_ptr = px_row_ptr;
for( x = 0; x < row_size; ++px_ptr ) {
row_pointers[y][x++] = px_ptr->red;
row_pointers[y][x++] = px_ptr->green;
row_pointers[y][x++] = px_ptr->blue;
row_pointers[y][x++] = px_ptr->alpha;
}
px_row_ptr += graph->w;
}
} else {
uchar_t *px_ptr, *px_row_ptr;
row_size = png_get_rowbytes( png_ptr, info_ptr );
px_row_ptr = graph->bytes + rect.top * graph->bytes_per_row;
px_row_ptr += rect.left * graph->bytes_per_pixel;
row_pointers = (png_bytep*)malloc( rect.height*sizeof( png_bytep ) );
for( y = 0; y < rect.height; ++y ) {
row_pointers[y] = (png_bytep)malloc( row_size );
px_ptr = px_row_ptr;
for( x = 0; x < row_size; x += 3 ) {
row_pointers[y][x + 2] = *px_ptr++; // blue
row_pointers[y][x + 1] = *px_ptr++; // green
row_pointers[y][x] = *px_ptr++; // red
}
px_row_ptr += graph->bytes_per_row;
}
}
png_write_image( png_ptr, row_pointers );
/* cleanup heap allocation */
for( y = 0; y < rect.height; ++y ) {
free( row_pointers[y] );
}
free( row_pointers );
/* end write */
png_write_end( png_ptr, NULL );
png_destroy_write_struct( &png_ptr, &info_ptr );
fclose( fp );
return 0;
#else
printf( "warning: not PNG support!" );
return 0;
#endif
}
