src/test/SDL_test_compare.c
author Philipp Wiesemann
Tue, 30 Aug 2016 21:16:04 +0200
changeset 10298 06e7d0ccbc11
parent 10037 e2343ac4788e
child 10737 3406a0f8b041
permissions -rw-r--r--
Fixed log message in audio capture test program.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /*
    23 
    24  Based on automated SDL_Surface tests originally written by Edgar Simo 'bobbens'.
    25 
    26  Rewritten for test lib by Andreas Schiffler.
    27 
    28 */
    29 
    30 #include "SDL_config.h"
    31 
    32 #include "SDL_test.h"
    33 
    34 
    35 /* Counter for _CompareSurface calls; used for filename creation when comparisons fail */
    36 static int _CompareSurfaceCount = 0;
    37 
    38 /* Compare surfaces */
    39 int SDLTest_CompareSurfaces(SDL_Surface *surface, SDL_Surface *referenceSurface, int allowable_error)
    40 {
    41    int ret;
    42    int i,j;
    43    int bpp, bpp_reference;
    44    Uint8 *p, *p_reference;
    45    int dist;
    46    int sampleErrorX = 0, sampleErrorY = 0, sampleDist = 0;
    47    Uint8 R, G, B, A;
    48    Uint8 Rd, Gd, Bd, Ad;
    49    char imageFilename[128];
    50    char referenceFilename[128];
    51 
    52    /* Validate input surfaces */
    53    if (surface == NULL || referenceSurface == NULL) {
    54       return -1;
    55    }
    56 
    57    /* Make sure surface size is the same. */
    58    if ((surface->w != referenceSurface->w) || (surface->h != referenceSurface->h)) {
    59       return -2;
    60    }
    61 
    62    /* Sanitize input value */
    63    if (allowable_error<0) {
    64       allowable_error = 0;
    65    }
    66 
    67    SDL_LockSurface( surface );
    68    SDL_LockSurface( referenceSurface );
    69 
    70    ret = 0;
    71    bpp = surface->format->BytesPerPixel;
    72    bpp_reference = referenceSurface->format->BytesPerPixel;
    73    /* Compare image - should be same format. */
    74    for (j=0; j<surface->h; j++) {
    75       for (i=0; i<surface->w; i++) {
    76          p  = (Uint8 *)surface->pixels + j * surface->pitch + i * bpp;
    77          p_reference = (Uint8 *)referenceSurface->pixels + j * referenceSurface->pitch + i * bpp_reference;
    78 
    79          SDL_GetRGBA(*(Uint32*)p, surface->format, &R, &G, &B, &A);
    80          SDL_GetRGBA(*(Uint32*)p_reference, referenceSurface->format, &Rd, &Gd, &Bd, &Ad);
    81 
    82          dist = 0;
    83          dist += (R-Rd)*(R-Rd);
    84          dist += (G-Gd)*(G-Gd);
    85          dist += (B-Bd)*(B-Bd);
    86 
    87          /* Allow some difference in blending accuracy */
    88          if (dist > allowable_error) {
    89             ret++;
    90             if (ret == 1) {
    91                sampleErrorX = i;
    92                sampleErrorY = j;
    93                sampleDist = dist;
    94             }
    95          }
    96       }
    97    }
    98 
    99    SDL_UnlockSurface( surface );
   100    SDL_UnlockSurface( referenceSurface );
   101 
   102    /* Save test image and reference for analysis on failures */
   103    _CompareSurfaceCount++;
   104    if (ret != 0) {
   105       SDLTest_LogError("Comparison of pixels with allowable error of %i failed %i times.", allowable_error, ret);
   106       SDLTest_LogError("First detected occurrence at position %i,%i with a squared RGB-difference of %i.", sampleErrorX, sampleErrorY, sampleDist); 
   107       SDL_snprintf(imageFilename, 127, "CompareSurfaces%04d_TestOutput.bmp", _CompareSurfaceCount);
   108       SDL_SaveBMP(surface, imageFilename);
   109       SDL_snprintf(referenceFilename, 127, "CompareSurfaces%04d_Reference.bmp", _CompareSurfaceCount);
   110       SDL_SaveBMP(referenceSurface, referenceFilename);
   111       SDLTest_LogError("Surfaces from failed comparison saved as '%s' and '%s'", imageFilename, referenceFilename);
   112    }
   113 
   114    return ret;
   115 }