view test/automated/common/common.h @ 3333:b334b4f7dfa0

[SDL] Bad math in SDL_RenderCopy Mason Wheeler to sdl When I tried to render an image using something other than NULL for srcrect, it got horribly distorted. I traced it down to the fact that the math in the rectangle adjustments performed just before the call to renderer->RenderCopy is written inside out. It should look like this: if (dstrect->w != real_dstrect.w) { int deltax = (dstrect->x - real_dstrect.x); int deltaw = (dstrect->w - real_dstrect.w); real_srcrect.x += (deltax * real_srcrect.w) / dstrect->w; real_srcrect.w += (deltaw * real_srcrect.w) / dstrect->w; } if (dstrect->h != real_dstrect.h) { int deltay = (dstrect->y - real_dstrect.y); int deltah = (dstrect->h - real_dstrect.h); real_srcrect.y += (deltay * real_srcrect.h) / dstrect->h; real_srcrect.h += (deltah * real_srcrect.h) / dstrect->h;
author Sam Lantinga <slouken@libsdl.org>
date Sat, 03 Oct 2009 16:23:16 +0000
parents 22ac66da0765
children 9f62f47d989b
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/**
 * Automated SDL test common framework.
 *
 * Written by Edgar Simo "bobbens"
 *
 * Released under Public Domain.
 */


#ifndef COMMON_H
#  define COMMON_H


#if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
#  define RMASK   0xff000000 /**< Red bit mask. */
#  define GMASK   0x00ff0000 /**< Green bit mask. */
#  define BMASK   0x0000ff00 /**< Blue bit mask. */
#  define AMASK   0x000000ff /**< Alpha bit mask. */
#else
#  define RMASK   0x000000ff /**< Red bit mask. */
#  define GMASK   0x0000ff00 /**< Green bit mask. */
#  define BMASK   0x00ff0000 /**< Blue bit mask. */
#  define AMASK   0xff000000 /**< Alpha bit mask. */
#endif


typedef struct SurfaceImage_s {
   int width;
   int height;
   unsigned int  bytes_per_pixel; /* 3:RGB, 4:RGBA */ 
   const unsigned char pixel_data[];
} SurfaceImage_t;


/**
 * @brief Compares a surface and a surface image for equality.
 *
 *    @param sur Surface to compare.
 *    @param img Image to compare against.
 *    @return 0 if they are the same, -1 on error and positive if different.
 */
int surface_compare( SDL_Surface *sur, const SurfaceImage_t *img );


#endif /* COMMON_H */