SDL 3.0
SDL_test_compare.h
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1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2023 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 * \file SDL_test_compare.h
24 *
25 * Comparison function of SDL test framework.
26 *
27 * This code is a part of the SDL test library, not the main SDL library.
28 */
29
30/*
31
32 Defines comparison functions (i.e. for surfaces).
33
34*/
35
36#ifndef SDL_test_compare_h_
37#define SDL_test_compare_h_
38
39#include <SDL3/SDL.h>
40
41#include <SDL3/SDL_begin_code.h>
42/* Set up for C function definitions, even when using C++ */
43#ifdef __cplusplus
44extern "C" {
45#endif
46
47/**
48 * Retrieves a single pixel from a surface.
49 *
50 * This function prioritizes correctness over speed: it is suitable for
51 * unit tests, but is not intended for use in a game engine.
52 *
53 * Like SDL_GetRGBA, this uses the entire 0..255 range when converting
54 * color components from pixel formats with less than 8 bits per RGB
55 * component.
56 *
57 * \param surface The surface
58 * \param x Horizontal coordinate, 0 <= x < width
59 * \param y Vertical coordinate, 0 <= y < height
60 * \param r Pointer to location to store red channel, 0-255
61 * \param g Pointer to location to store green channel, 0-255
62 * \param b Pointer to location to store blue channel, 0-255
63 * \param a Pointer to location to store alpha channel, 0-255
64 * \returns 0 if the surface is valid and the coordinates are in-bounds
65 */
66int SDLTest_ReadSurfacePixel(SDL_Surface *surface, int x, int y, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);
67
68/**
69 * Compares a surface and with reference image data for equality
70 *
71 * \param surface Surface used in comparison
72 * \param referenceSurface Test Surface used in comparison
73 * \param allowable_error Allowable difference (=sum of squared difference for each RGB component) in blending accuracy.
74 *
75 * \returns 0 if comparison succeeded, >0 (=number of pixels for which the comparison failed) if comparison failed, -1 if any of the surfaces were NULL, -2 if the surface sizes differ.
76 */
77int SDLTest_CompareSurfaces(SDL_Surface *surface, SDL_Surface *referenceSurface, int allowable_error);
78
79
80/* Ends C function definitions when using C++ */
81#ifdef __cplusplus
82}
83#endif
84#include <SDL3/SDL_close_code.h>
85
86#endif /* SDL_test_compare_h_ */
uint8_t Uint8
Definition SDL_stdinc.h:149
int SDLTest_CompareSurfaces(SDL_Surface *surface, SDL_Surface *referenceSurface, int allowable_error)
int SDLTest_ReadSurfacePixel(SDL_Surface *surface, int x, int y, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a)