kc3-lang/SDL/test/testdrawchessboard.c

Branch : - branch - v2.28 - tag -

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  Commit

• Author : Sam Lantinga
  Date : 2017-08-13 21:12:14
  Hash : 93a520b3
  Message : Fixed bug 3605 - Software renderer no longer renders after Android screen orientation change Sylvain This still happens with the current trunk version. (software renderer of testdrawchessboard.c) When there is a rotation, the window size changed and the internal surface is marked as "surface_valid == SDL_FALSE". And all further call fails. SDL_video.c : 2478 void 2479 SDL_OnWindowResized(SDL_Window * window) 2480 { 2481 window->surface_valid = SDL_FALSE; 2482 SDL_SendWindowEvent(window, SDL_WINDOWEVENT_SIZE_CHANGED, window->w, window->h); 2483 } some error set to : 2233 return SDL_SetError("Window surface is invalid, please call SDL_GetWindowSurface() to get a new surface"); So, this seems to be the behavior of the API ... In the loop() function of testdrawchessboard.c, we can recreate the surface/renderer : 65 if (e.type == SDL_WINDOWEVENT) 66 { 67 if (e.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) 68 { 69 surface = SDL_GetWindowSurface(window); 70 renderer = SDL_CreateSoftwareRenderer(surface); 71 } 72 /* Clear the rendering surface with the specified color */ 73 SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF); 74 SDL_RenderClear(renderer); 75 } And it displays correctly.

• test/testdrawchessboard.c

• /*
     Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  
     This software is provided 'as-is', without any express or implied
     warranty.  In no event will the authors be held liable for any damages
     arising from the use of this software.
  
     Permission is granted to anyone to use this software for any purpose,
     including commercial applications, and to alter it and redistribute it
     freely.
  
     This file is created by : Nitin Jain (nitin.j4@samsung.com)
  */
  
  /* Sample program:  Draw a Chess Board  by using SDL_CreateSoftwareRenderer API */
  
  #include <stdlib.h>
  #include <stdio.h>
  
  #ifdef __EMSCRIPTEN__
  #include <emscripten/emscripten.h>
  #endif
  
  #include "SDL.h"
  
  SDL_Window *window;
  SDL_Renderer *renderer;
  SDL_Surface *surface;
  int done;
  
  void
  DrawChessBoard(SDL_Renderer * renderer)
  {
      int row = 0,column = 0,x = 0;
      SDL_Rect rect, darea;
  
      /* Get the Size of drawing surface */
      SDL_RenderGetViewport(renderer, &darea);
  
      for( ; row < 8; row++)
      {
          column = row%2;
          x = column;
          for( ; column < 4+(row%2); column++)
          {
              SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0xFF);
  
              rect.w = darea.w/8;
              rect.h = darea.h/8;
              rect.x = x * rect.w;
              rect.y = row * rect.h;
              x = x + 2;
              SDL_RenderFillRect(renderer, &rect);
          }
      }
  }
  
  void
  loop()
  {
      SDL_Event e;
      while (SDL_PollEvent(&e)) {
         
         /* Re-create when window has been resized */
         if ((e.type == SDL_WINDOWEVENT) && (e.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)) {
  
            SDL_DestroyRenderer(renderer);
  
            surface = SDL_GetWindowSurface(window);
            renderer = SDL_CreateSoftwareRenderer(surface);
            /* Clear the rendering surface with the specified color */
            SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
            SDL_RenderClear(renderer);
         }
  
         if (e.type == SDL_QUIT) {
              done = 1;
  #ifdef __EMSCRIPTEN__
              emscripten_cancel_main_loop();
  #endif
              return;
          }
  
          if ((e.type == SDL_KEYDOWN) && (e.key.keysym.sym == SDLK_ESCAPE)) {
              done = 1;
  #ifdef __EMSCRIPTEN__
              emscripten_cancel_main_loop();
  #endif
              return;
          }
      }
  
      DrawChessBoard(renderer);
  
      /* Got everything on rendering surface,
         now Update the drawing image on window screen */
      SDL_UpdateWindowSurface(window);
  }
  
  int
  main(int argc, char *argv[])
  {
      /* Enable standard application logging */
      SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
  
      /* Initialize SDL */
      if(SDL_Init(SDL_INIT_VIDEO) != 0)
      {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_Init fail : %s\n", SDL_GetError());
          return 1;
      }
  
  
      /* Create window and renderer for given surface */
      window = SDL_CreateWindow("Chess Board", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_RESIZABLE);
      if(!window)
      {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Window creation fail : %s\n",SDL_GetError());
          return 1;
      }
      surface = SDL_GetWindowSurface(window);
      renderer = SDL_CreateSoftwareRenderer(surface);
      if(!renderer)
      {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Render creation for surface fail : %s\n",SDL_GetError());
          return 1;
      }
  
      /* Clear the rendering surface with the specified color */
      SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
      SDL_RenderClear(renderer);
  
  
      /* Draw the Image on rendering surface */
      done = 0;
  #ifdef __EMSCRIPTEN__
      emscripten_set_main_loop(loop, 0, 1);
  #else
      while (!done) {
          loop();
      }
  #endif
  
      SDL_Quit();
      return 0;
  }