go-libwebp

Experimental translation from libwebp to Go source.
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webp_to_sdl.c (2819B)

      1 // Copyright 2017 Google Inc. All Rights Reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style license
      4 // that can be found in the COPYING file in the root of the source
      5 // tree. An additional intellectual property rights grant can be found
      6 // in the file PATENTS. All contributing project authors may
      7 // be found in the AUTHORS file in the root of the source tree.
      8 // -----------------------------------------------------------------------------
      9 //
     10 //  Simple WebP-to-SDL wrapper. Useful for emscripten.
     11 //
     12 // Author: James Zern (jzern@google.com)
     13 
     14 #ifdef HAVE_CONFIG_H
     15 #include "src/webp/config.h"
     16 #endif
     17 
     18 #if defined(WEBP_HAVE_SDL)
     19 
     20 #include "webp_to_sdl.h"
     21 
     22 #include <stdio.h>
     23 
     24 #include "src/webp/decode.h"
     25 
     26 #if defined(WEBP_HAVE_JUST_SDL_H)
     27 #include <SDL.h>
     28 #else
     29 #include <SDL2/SDL.h>
     30 #endif
     31 
     32 static int init_ok = 0;
     33 int WebPToSDL(const char* data, unsigned int data_size) {
     34   int ok = 0;
     35   VP8StatusCode status;
     36   WebPBitstreamFeatures input;
     37   uint8_t* output = NULL;
     38   SDL_Window* window = NULL;
     39   SDL_Renderer* renderer = NULL;
     40   SDL_Texture* texture = NULL;
     41   int width, height;
     42 
     43   if (!init_ok) {
     44     SDL_Init(SDL_INIT_VIDEO);
     45     init_ok = 1;
     46   }
     47 
     48   status = WebPGetFeatures((uint8_t*)data, (size_t)data_size, &input);
     49   if (status != VP8_STATUS_OK) goto Error;
     50   width = input.width;
     51   height = input.height;
     52 
     53   SDL_CreateWindowAndRenderer(width, height, 0, &window, &renderer);
     54   if (window == NULL || renderer == NULL) {
     55     fprintf(stderr, "Unable to create window or renderer!\n");
     56     goto Error;
     57   }
     58   SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY,
     59               "linear");  // make the scaled rendering look smoother.
     60   SDL_RenderSetLogicalSize(renderer, width, height);
     61 
     62   texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ABGR8888,
     63                               SDL_TEXTUREACCESS_STREAMING, width, height);
     64   if (texture == NULL) {
     65     fprintf(stderr, "Unable to create %dx%d RGBA texture!\n", width, height);
     66     goto Error;
     67   }
     68 
     69 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
     70   output = WebPDecodeBGRA((const uint8_t*)data, (size_t)data_size, &width,
     71                           &height);
     72 #else
     73   output = WebPDecodeRGBA((const uint8_t*)data, (size_t)data_size, &width,
     74                           &height);
     75 #endif
     76   if (output == NULL) {
     77     fprintf(stderr, "Error decoding image (%d)\n", status);
     78     goto Error;
     79   }
     80 
     81   SDL_UpdateTexture(texture, NULL, output, width * sizeof(uint32_t));
     82   SDL_RenderClear(renderer);
     83   SDL_RenderCopy(renderer, texture, NULL, NULL);
     84   SDL_RenderPresent(renderer);
     85   ok = 1;
     86 
     87  Error:
     88   // We should call SDL_DestroyWindow(window) but that makes .js fail.
     89   SDL_DestroyRenderer(renderer);
     90   SDL_DestroyTexture(texture);
     91   WebPFree(output);
     92   return ok;
     93 }
     94 
     95 //------------------------------------------------------------------------------
     96 
     97 #endif  // WEBP_HAVE_SDL