SDL/test/testautomation_surface.c

/**
 * Original code: automated SDL surface test written by Edgar Simo "bobbens"
 * Adapted/rewritten for test lib by Andreas Schiffler
 */

/* Suppress C4996 VS compiler warnings for unlink() */
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
#define _CRT_SECURE_NO_DEPRECATE
#endif
#if defined(_MSC_VER) && !defined(_CRT_NONSTDC_NO_DEPRECATE)
#define _CRT_NONSTDC_NO_DEPRECATE
#endif

#include <stdio.h>
#ifndef _MSC_VER
#include <unistd.h>
#endif
#include <sys/stat.h>

#include <SDL3/SDL.h>
#include <SDL3/SDL_test.h>
#include "testautomation_suites.h"
#include "testautomation_images.h"


#define CHECK_FUNC(FUNC, PARAMS)    \
{                                   \
    int result = FUNC PARAMS;       \
    if (result != 0) {              \
        SDLTest_AssertCheck(result == 0, "Validate result from %s, expected: 0, got: %i, %s", #FUNC, result, SDL_GetError()); \
    }                               \
}

/* ================= Test Case Implementation ================== */

/* Shared test surface */

static SDL_Surface *referenceSurface = NULL;
static SDL_Surface *testSurface = NULL;

/* Fixture */

/* Create a 32-bit writable surface for blitting tests */
static void surfaceSetUp(void *arg)
{
    int result;
    SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
    SDL_BlendMode currentBlendMode;

    referenceSurface = SDLTest_ImageBlit(); /* For size info */
    testSurface = SDL_CreateSurface(referenceSurface->w, referenceSurface->h, SDL_PIXELFORMAT_RGBA32);
    SDLTest_AssertCheck(testSurface != NULL, "Check that testSurface is not NULL");
    if (testSurface != NULL) {
        /* Disable blend mode for target surface */
        result = SDL_SetSurfaceBlendMode(testSurface, blendMode);
        SDLTest_AssertCheck(result == 0, "Validate result from SDL_SetSurfaceBlendMode, expected: 0, got: %i", result);
        result = SDL_GetSurfaceBlendMode(testSurface, &currentBlendMode);
        SDLTest_AssertCheck(result == 0, "Validate result from SDL_GetSurfaceBlendMode, expected: 0, got: %i", result);
        SDLTest_AssertCheck(currentBlendMode == blendMode, "Validate blendMode, expected: %" SDL_PRIu32 ", got: %" SDL_PRIu32, blendMode, currentBlendMode);

        /* Clear the target surface */
        result = SDL_FillSurfaceRect(testSurface, NULL, SDL_MapSurfaceRGBA(testSurface, 0, 0, 0, 255));
        SDLTest_AssertCheck(result == 0, "Validate result from SDL_FillSurfaceRect, expected: 0, got: %i", result);
    }
}

static void surfaceTearDown(void *arg)
{
    SDL_DestroySurface(referenceSurface);
    referenceSurface = NULL;
    SDL_DestroySurface(testSurface);
    testSurface = NULL;
}

static void DitherPalette(SDL_Palette *palette)
{
    int i;

    for (i = 0; i < palette->ncolors; i++) {
        int r, g, b;
        /* map each bit field to the full [0, 255] interval,
           so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
        r = i & 0xe0;
        r |= r >> 3 | r >> 6;
        palette->colors[i].r = (Uint8)r;
        g = (i << 3) & 0xe0;
        g |= g >> 3 | g >> 6;
        palette->colors[i].g = (Uint8)g;
        b = i & 0x3;
        b |= b << 2;
        b |= b << 4;
        palette->colors[i].b = (Uint8)b;
        palette->colors[i].a = SDL_ALPHA_OPAQUE;
    }
}

/**
 * Helper that blits in a specific blend mode, -1 for color mod, -2 for alpha mod
 */
static void testBlitBlendModeWithFormats(int mode, SDL_PixelFormat src_format, SDL_PixelFormat dst_format)
{
    /* Allow up to 1 delta from theoretical value to account for rounding error */
    const int MAXIMUM_ERROR = 1;
    int ret;
    SDL_Surface *src;
    SDL_Surface *dst;
    Uint32 color;
    Uint8 srcR = 10, srcG = 128, srcB = 240, srcA = 100;
    Uint8 dstR = 128, dstG = 128, dstB = 128, dstA = 128;
    Uint8 expectedR, expectedG, expectedB, expectedA;
    Uint8 actualR, actualG, actualB, actualA;
    int deltaR, deltaG, deltaB, deltaA;

    /* Create dst surface */
    dst = SDL_CreateSurface(1, 1, dst_format);
    SDLTest_AssertCheck(dst != NULL, "Verify dst surface is not NULL");
    if (dst == NULL) {
        return;
    }

    /* Clear surface. */
    if (SDL_ISPIXELFORMAT_INDEXED(dst_format)) {
        SDL_Palette *palette = SDL_CreateSurfacePalette(dst);
        DitherPalette(palette);
        palette->colors[0].r = dstR;
        palette->colors[0].g = dstG;
        palette->colors[0].b = dstB;
        palette->colors[0].a = dstA;
        color = 0;
    } else {
        color = SDL_MapSurfaceRGBA(dst, dstR, dstG, dstB, dstA);
        SDLTest_AssertPass("Call to SDL_MapSurfaceRGBA()");
    }
    ret = SDL_FillSurfaceRect(dst, NULL, color);
    SDLTest_AssertPass("Call to SDL_FillSurfaceRect()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_FillSurfaceRect, expected: 0, got: %i", ret);
    SDL_GetRGBA(color, SDL_GetPixelFormatDetails(dst->format), SDL_GetSurfacePalette(dst), &dstR, &dstG, &dstB, &dstA);

    /* Create src surface */
    src = SDL_CreateSurface(1, 1, src_format);
    SDLTest_AssertCheck(src != NULL, "Verify src surface is not NULL");
    if (src == NULL) {
        return;
    }
    if (SDL_ISPIXELFORMAT_INDEXED(src_format)) {
        SDL_Palette *palette = SDL_CreateSurfacePalette(src);
        palette->colors[0].r = srcR;
        palette->colors[0].g = srcG;
        palette->colors[0].b = srcB;
        palette->colors[0].a = srcA;
    }

    /* Reset alpha modulation */
    ret = SDL_SetSurfaceAlphaMod(src, 255);
    SDLTest_AssertPass("Call to SDL_SetSurfaceAlphaMod()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceAlphaMod(), expected: 0, got: %i", ret);

    /* Reset color modulation */
    ret = SDL_SetSurfaceColorMod(src, 255, 255, 255);
    SDLTest_AssertPass("Call to SDL_SetSurfaceColorMod()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceColorMod(), expected: 0, got: %i", ret);

    /* Reset color key */
    ret = SDL_SetSurfaceColorKey(src, SDL_FALSE, 0);
    SDLTest_AssertPass("Call to SDL_SetSurfaceColorKey()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceColorKey(), expected: 0, got: %i", ret);

    /* Clear surface. */
    color = SDL_MapSurfaceRGBA(src, srcR, srcG, srcB, srcA);
    SDLTest_AssertPass("Call to SDL_MapSurfaceRGBA()");
    ret = SDL_FillSurfaceRect(src, NULL, color);
    SDLTest_AssertPass("Call to SDL_FillSurfaceRect()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_FillSurfaceRect, expected: 0, got: %i", ret);
    SDL_GetRGBA(color, SDL_GetPixelFormatDetails(src->format), SDL_GetSurfacePalette(src), &srcR, &srcG, &srcB, &srcA);

    /* Set blend mode. */
    if (mode >= 0) {
        ret = SDL_SetSurfaceBlendMode(src, (SDL_BlendMode)mode);
        SDLTest_AssertPass("Call to SDL_SetSurfaceBlendMode()");
        SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceBlendMode(..., %i), expected: 0, got: %i", mode, ret);
    } else {
        ret = SDL_SetSurfaceBlendMode(src, SDL_BLENDMODE_BLEND);
        SDLTest_AssertPass("Call to SDL_SetSurfaceBlendMode()");
        SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceBlendMode(..., %i), expected: 0, got: %i", mode, ret);
    }

    /* Test blend mode. */
#define FLOAT(X)    ((float)X / 255.0f)
    switch (mode) {
    case -1:
        /* Set color mod. */
        ret = SDL_SetSurfaceColorMod(src, srcR, srcG, srcB);
        SDLTest_AssertCheck(ret == 0, "Validate results from calls to SDL_SetSurfaceColorMod, expected: 0, got: %i", ret);
        expectedR = (Uint8)SDL_roundf(SDL_clamp((FLOAT(srcR) * FLOAT(srcR)) * FLOAT(srcA) + FLOAT(dstR) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp((FLOAT(srcG) * FLOAT(srcG)) * FLOAT(srcA) + FLOAT(dstG) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp((FLOAT(srcB) * FLOAT(srcB)) * FLOAT(srcA) + FLOAT(dstB) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedA = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcA) + FLOAT(dstA) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        break;
    case -2:
        /* Set alpha mod. */
        ret = SDL_SetSurfaceAlphaMod(src, srcA);
        SDLTest_AssertCheck(ret == 0, "Validate results from calls to SDL_SetSurfaceAlphaMod, expected: 0, got: %i", ret);
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) * (FLOAT(srcA) * FLOAT(srcA)) + FLOAT(dstR) * (1.0f - (FLOAT(srcA) * FLOAT(srcA))), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) * (FLOAT(srcA) * FLOAT(srcA)) + FLOAT(dstG) * (1.0f - (FLOAT(srcA) * FLOAT(srcA))), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) * (FLOAT(srcA) * FLOAT(srcA)) + FLOAT(dstB) * (1.0f - (FLOAT(srcA) * FLOAT(srcA))), 0.0f, 1.0f) * 255.0f);
        expectedA = (Uint8)SDL_roundf(SDL_clamp((FLOAT(srcA) * FLOAT(srcA)) + FLOAT(dstA) * (1.0f - (FLOAT(srcA) * FLOAT(srcA))), 0.0f, 1.0f) * 255.0f);
        break;
    case SDL_BLENDMODE_NONE:
        expectedR = srcR;
        expectedG = srcG;
        expectedB = srcB;
        expectedA = SDL_ISPIXELFORMAT_ALPHA(dst_format) ? srcA : 255;
        break;
    case SDL_BLENDMODE_BLEND:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) * FLOAT(srcA) + FLOAT(dstR) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) * FLOAT(srcA) + FLOAT(dstG) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) * FLOAT(srcA) + FLOAT(dstB) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedA = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcA) + FLOAT(dstA) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        break;
    case SDL_BLENDMODE_BLEND_PREMULTIPLIED:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) + FLOAT(dstR) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) + FLOAT(dstG) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) + FLOAT(dstB) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedA = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcA) + FLOAT(dstA) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        break;
    case SDL_BLENDMODE_ADD:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) * FLOAT(srcA) + FLOAT(dstR), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) * FLOAT(srcA) + FLOAT(dstG), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) * FLOAT(srcA) + FLOAT(dstB), 0.0f, 1.0f) * 255.0f);
        expectedA = dstA;
        break;
    case SDL_BLENDMODE_ADD_PREMULTIPLIED:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) + FLOAT(dstR), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) + FLOAT(dstG), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) + FLOAT(dstB), 0.0f, 1.0f) * 255.0f);
        expectedA = dstA;
        break;
    case SDL_BLENDMODE_MOD:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) * FLOAT(dstR), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) * FLOAT(dstG), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) * FLOAT(dstB), 0.0f, 1.0f) * 255.0f);
        expectedA = dstA;
        break;
    case SDL_BLENDMODE_MUL:
        expectedR = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcR) * FLOAT(dstR) + FLOAT(dstR) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedG = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcG) * FLOAT(dstG) + FLOAT(dstG) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedB = (Uint8)SDL_roundf(SDL_clamp(FLOAT(srcB) * FLOAT(dstB) + FLOAT(dstB) * (1.0f - FLOAT(srcA)), 0.0f, 1.0f) * 255.0f);
        expectedA = dstA;
        break;
    default:
        SDLTest_LogError("Invalid blending mode: %d", mode);
        return;
    }

    if (SDL_ISPIXELFORMAT_INDEXED(dst_format)) {
        SDL_Palette *palette = SDL_GetSurfacePalette(dst);
        palette->colors[1].r = expectedR;
        palette->colors[1].g = expectedG;
        palette->colors[1].b = expectedB;
        palette->colors[1].a = expectedA;
    }

    /* Blitting. */
    ret = SDL_BlitSurface(src, NULL, dst, NULL);
    SDLTest_AssertCheck(ret == 0, "Validate results from calls to SDL_BlitSurface, expected: 0, got: %i: %s", ret, (ret < 0) ? SDL_GetError() : "success");
    if (ret == 0) {
        SDL_ReadSurfacePixel(dst, 0, 0, &actualR, &actualG, &actualB, &actualA);
        deltaR = SDL_abs((int)actualR - expectedR);
        deltaG = SDL_abs((int)actualG - expectedG);
        deltaB = SDL_abs((int)actualB - expectedB);
        deltaA = SDL_abs((int)actualA - expectedA);
        SDLTest_AssertCheck(
            deltaR <= MAXIMUM_ERROR &&
            deltaG <= MAXIMUM_ERROR &&
            deltaB <= MAXIMUM_ERROR &&
            deltaA <= MAXIMUM_ERROR,
            "Checking %s -> %s blit results, expected %d,%d,%d,%d, got %d,%d,%d,%d",
            SDL_GetPixelFormatName(src_format),
            SDL_GetPixelFormatName(dst_format),
            expectedR, expectedG, expectedB, expectedA, actualR, actualG, actualB, actualA);
    }

    /* Clean up */
    SDL_DestroySurface(src);
    SDL_DestroySurface(dst);
}

static void testBlitBlendMode(int mode)
{
    const SDL_PixelFormat src_formats[] = {
        SDL_PIXELFORMAT_INDEX8, SDL_PIXELFORMAT_XRGB8888, SDL_PIXELFORMAT_ARGB8888
    };
    const SDL_PixelFormat dst_formats[] = {
        SDL_PIXELFORMAT_XRGB8888, SDL_PIXELFORMAT_ARGB8888
    };
    int i, j;

    for (i = 0; i < SDL_arraysize(src_formats); ++i) {
        for (j = 0; j < SDL_arraysize(dst_formats); ++j) {
            testBlitBlendModeWithFormats(mode, src_formats[i], dst_formats[j]);
        }
    }
}

/* Helper to check that a file exists */
static void AssertFileExist(const char *filename)
{
    struct stat st;
    int ret = stat(filename, &st);

    SDLTest_AssertCheck(ret == 0, "Verify file '%s' exists", filename);
}

/* Test case functions */

/**
 * Tests sprite saving and loading
 */
static int surface_testSaveLoadBitmap(void *arg)
{
    int ret;
    const char *sampleFilename = "testSaveLoadBitmap.bmp";
    SDL_Surface *face;
    SDL_Surface *rface;

    /* Create sample surface */
    face = SDLTest_ImageFace();
    SDLTest_AssertCheck(face != NULL, "Verify face surface is not NULL");
    if (face == NULL) {
        return TEST_ABORTED;
    }

    /* Delete test file; ignore errors */
    unlink(sampleFilename);

    /* Save a surface */
    ret = SDL_SaveBMP(face, sampleFilename);
    SDLTest_AssertPass("Call to SDL_SaveBMP()");
    SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SaveBMP, expected: 0, got: %i", ret);
    AssertFileExist(sampleFilename);

    /* Load a surface */
    rface = SDL_LoadBMP(sampleFilename);
    SDLTest_AssertPass("Call to SDL_LoadBMP()");
    SDLTest_AssertCheck(rface != NULL, "Verify result from SDL_LoadBMP is not NULL");
    if (rface != NULL) {
        SDLTest_AssertCheck(face->w == rface->w, "Verify width of loaded surface, expected: %i, got: %i", face->w, rface->w);
        SDLTest_AssertCheck(face->h == rface->h, "Verify height of loaded surface, expected: %i, got: %i", face->h, rface->h);
    }

    /* Delete test file; ignore errors */
    unlink(sampleFilename);

    /* Clean up */
    SDL_DestroySurface(face);
    face = NULL;
    SDL_DestroySurface(rface);
    rface = NULL;

    return TEST_COMPLETED;
}

/**
 *  Tests tiled blitting.
 */
static int surface_testBlitTiled(void *arg)
{
    SDL_Surface *face = NULL;
    SDL_Surface *testSurface2x = NULL;
    SDL_Surface *referenceSurface2x = NULL;
    int ret = 0;

    /* Create sample surface */
    face = SDLTest_ImageFace();
    SDLTest_AssertCheck(face != NULL, "Verify face surface is not NULL");
    if (face == NULL) {
        return TEST_ABORTED;
    }

    /* Tiled blit - 1.0 scale */
    {
        ret = SDL_BlitSurfaceTiled(face, NULL, testSurface, NULL);
        SDLTest_AssertCheck(ret == 0, "Verify result from SDL_BlitSurfaceTiled expected: 0, got: %i", ret);

        /* See if it's the same */
        SDL_DestroySurface(referenceSurface);
        referenceSurface = SDLTest_ImageBlitTiled();
        ret = SDLTest_CompareSurfaces(testSurface, referenceSurface, 0);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);
    }

    /* Tiled blit - 2.0 scale */
    {
        testSurface2x = SDL_CreateSurface(testSurface->w * 2, testSurface->h * 2, testSurface->format);
        SDLTest_AssertCheck(testSurface != NULL, "Check that testSurface2x is not NULL");
        ret = SDL_FillSurfaceRect(testSurface2x, NULL, SDL_MapSurfaceRGBA(testSurface2x, 0, 0, 0, 255));
        SDLTest_AssertCheck(ret == 0, "Validate result from SDL_FillSurfaceRect, expected: 0, got: %i", ret);

        ret = SDL_BlitSurfaceTiledWithScale(face, NULL, 2.0f, SDL_SCALEMODE_NEAREST, testSurface2x, NULL);
        SDLTest_AssertCheck(ret == 0, "Validate results from call to SDL_RenderTextureTiled, expected: 0, got: %i", ret);

        /* See if it's the same */
        referenceSurface2x = SDL_CreateSurface(referenceSurface->w * 2, referenceSurface->h * 2, referenceSurface->format);
        SDL_BlitSurfaceScaled(referenceSurface, NULL, referenceSurface2x, NULL, SDL_SCALEMODE_NEAREST);
        SDLTest_AssertCheck(ret == 0, "Validate results from call to SDL_BlitSurfaceScaled, expected: 0, got: %i", ret);
        ret = SDLTest_CompareSurfaces(testSurface2x, referenceSurface2x, 0);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);
    }

    /* Clean up. */
    SDL_DestroySurface(face);
    SDL_DestroySurface(testSurface2x);
    SDL_DestroySurface(referenceSurface2x);

    return TEST_COMPLETED;
}

static const Uint8 COLOR_SEPARATION = 85;

static void Fill9GridReferenceSurface(SDL_Surface *surface, int corner_size)
{
    SDL_Rect rect;

    // Upper left
    rect.x = 0;
    rect.y = 0;
    rect.w = corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 1 * COLOR_SEPARATION, 1 * COLOR_SEPARATION, 0));

    // Top
    rect.x = corner_size;
    rect.y = 0;
    rect.w = surface->w - 2 * corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 2 * COLOR_SEPARATION, 1 * COLOR_SEPARATION, 0));

    // Upper right
    rect.x = surface->w - corner_size;
    rect.y = 0;
    rect.w = corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 3 * COLOR_SEPARATION, 1 * COLOR_SEPARATION, 0));

    // Left
    rect.x = 0;
    rect.y = corner_size;
    rect.w = corner_size;
    rect.h = surface->h - 2 * corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 1 * COLOR_SEPARATION, 2 * COLOR_SEPARATION, 0));

    // Center
    rect.x = corner_size;
    rect.y = corner_size;
    rect.w = surface->w - 2 * corner_size;
    rect.h = surface->h - 2 * corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 2 * COLOR_SEPARATION, 2 * COLOR_SEPARATION, 0));

    // Right
    rect.x = surface->w - corner_size;
    rect.y = corner_size;
    rect.w = corner_size;
    rect.h = surface->h - 2 * corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 3 * COLOR_SEPARATION, 2 * COLOR_SEPARATION, 0));

    // Lower left
    rect.x = 0;
    rect.y = surface->h - corner_size;
    rect.w = corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 1 * COLOR_SEPARATION, 3 * COLOR_SEPARATION, 0));

    // Bottom
    rect.x = corner_size;
    rect.y = surface->h - corner_size;
    rect.w = surface->w - 2 * corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 2 * COLOR_SEPARATION, 3 * COLOR_SEPARATION, 0));

    // Lower right
    rect.x = surface->w - corner_size;
    rect.y = surface->h - corner_size;
    rect.w = corner_size;
    rect.h = corner_size;
    SDL_FillSurfaceRect(surface, &rect, SDL_MapSurfaceRGB(surface, 3 * COLOR_SEPARATION, 3 * COLOR_SEPARATION, 0));
}

/**
 *  Tests 9-grid blitting.
 */
static int surface_testBlit9Grid(void *arg)
{
    SDL_Surface *source = NULL;
    int x, y;
    int ret = 0;

    /* Create source surface */
    source = SDL_CreateSurface(3, 3, SDL_PIXELFORMAT_RGBA32);
    SDLTest_AssertCheck(source != NULL, "Verify source surface is not NULL");
    for (y = 0; y < 3; ++y) {
        for (x = 0; x < 3; ++x) {
            SDL_WriteSurfacePixel(source, x, y, (Uint8)((1 + x) * COLOR_SEPARATION), (Uint8)((1 + y) * COLOR_SEPARATION), 0, 255);
        }
    }

    /* 9-grid blit - 1.0 scale */
    {
        /* Create reference surface */
        SDL_DestroySurface(referenceSurface);
        referenceSurface = SDL_CreateSurface(testSurface->w, testSurface->h, testSurface->format);
        SDLTest_AssertCheck(referenceSurface != NULL, "Verify reference surface is not NULL");
        Fill9GridReferenceSurface(referenceSurface, 1);

        ret = SDL_BlitSurface9Grid(source, NULL, 1, 0.0f, SDL_SCALEMODE_NEAREST, testSurface, NULL);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDL_BlitSurface9Grid, expected: 0, got: %i", ret);

        ret = SDLTest_CompareSurfaces(testSurface, referenceSurface, 0);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);
    }

    /* 9-grid blit - 2.0 scale */
    {
        /* Create reference surface */
        SDL_DestroySurface(referenceSurface);
        referenceSurface = SDL_CreateSurface(testSurface->w, testSurface->h, testSurface->format);
        SDLTest_AssertCheck(referenceSurface != NULL, "Verify reference surface is not NULL");
        Fill9GridReferenceSurface(referenceSurface, 2);

        ret = SDL_BlitSurface9Grid(source, NULL, 1, 2.0f, SDL_SCALEMODE_NEAREST, testSurface, NULL);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDL_BlitSurface9Grid, expected: 0, got: %i", ret);

        ret = SDLTest_CompareSurfaces(testSurface, referenceSurface, 0);
        SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);
    }

    /* Clean up. */
    SDL_DestroySurface(source);

    return TEST_COMPLETED;
}

/**
 *  Tests surface conversion.
 */
static int surface_testSurfaceConversion(void *arg)
{
    SDL_Surface *rface = NULL, *face = NULL;
    int ret = 0;

    /* Create sample surface */
    face = SDLTest_ImageFace();
    SDLTest_AssertCheck(face != NULL, "Verify face surface is not NULL");
    if (face == NULL) {
        return TEST_ABORTED;
    }

    /* Set transparent pixel as the pixel at (0,0) */
    if (SDL_GetSurfacePalette(face)) {
        ret = SDL_SetSurfaceColorKey(face, SDL_TRUE, *(Uint8 *)face->pixels);
        SDLTest_AssertPass("Call to SDL_SetSurfaceColorKey()");
        SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceColorKey, expected: 0, got: %i", ret);
    }

    /* Convert to 32 bit to compare. */
    rface = SDL_ConvertSurface(face, testSurface->format);
    SDLTest_AssertPass("Call to SDL_ConvertSurface()");
    SDLTest_AssertCheck(rface != NULL, "Verify result from SDL_ConvertSurface is not NULL");

    /* Compare surface. */
    ret = SDLTest_CompareSurfaces(rface, face, 0);
    SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);

    /* Clean up. */
    SDL_DestroySurface(face);
    face = NULL;
    SDL_DestroySurface(rface);
    rface = NULL;

    return TEST_COMPLETED;
}

/**
 *  Tests surface conversion across all pixel formats.
 */
static int surface_testCompleteSurfaceConversion(void *arg)
{
    Uint32 pixel_formats[] = {
        SDL_PIXELFORMAT_INDEX8,
        SDL_PIXELFORMAT_RGB332,
        SDL_PIXELFORMAT_XRGB4444,
        SDL_PIXELFORMAT_XBGR4444,
        SDL_PIXELFORMAT_XRGB1555,
        SDL_PIXELFORMAT_XBGR1555,
        SDL_PIXELFORMAT_ARGB4444,
        SDL_PIXELFORMAT_RGBA4444,
        SDL_PIXELFORMAT_ABGR4444,
        SDL_PIXELFORMAT_BGRA4444,
        SDL_PIXELFORMAT_ARGB1555,
        SDL_PIXELFORMAT_RGBA5551,
        SDL_PIXELFORMAT_ABGR1555,
        SDL_PIXELFORMAT_BGRA5551,
        SDL_PIXELFORMAT_RGB565,
        SDL_PIXELFORMAT_BGR565,
        SDL_PIXELFORMAT_RGB24,
        SDL_PIXELFORMAT_BGR24,
        SDL_PIXELFORMAT_XRGB8888,
        SDL_PIXELFORMAT_RGBX8888,
        SDL_PIXELFORMAT_XBGR8888,
        SDL_PIXELFORMAT_BGRX8888,
        SDL_PIXELFORMAT_ARGB8888,
        SDL_PIXELFORMAT_RGBA8888,
        SDL_PIXELFORMAT_ABGR8888,
        SDL_PIXELFORMAT_BGRA8888,
#if 0 /* We aren't testing HDR10 colorspace conversion */
        SDL_PIXELFORMAT_XRGB2101010,
        SDL_PIXELFORMAT_XBGR2101010,
        SDL_PIXELFORMAT_ARGB2101010,
        SDL_PIXELFORMAT_ABGR2101010,
#endif
    };
    SDL_Surface *face = NULL, *cvt1, *cvt2, *final;
    const SDL_PixelFormatDetails *fmt1, *fmt2;
    int i, j, ret = 0;

    /* Create sample surface */
    face = SDLTest_ImageFace();
    SDLTest_AssertCheck(face != NULL, "Verify face surface is not NULL");
    if (face == NULL) {
        return TEST_ABORTED;
    }

    /* Set transparent pixel as the pixel at (0,0) */
    if (SDL_GetSurfacePalette(face)) {
        ret = SDL_SetSurfaceColorKey(face, SDL_TRUE, *(Uint8 *)face->pixels);
        SDLTest_AssertPass("Call to SDL_SetSurfaceColorKey()");
        SDLTest_AssertCheck(ret == 0, "Verify result from SDL_SetSurfaceColorKey, expected: 0, got: %i", ret);
    }

    for (i = 0; i < SDL_arraysize(pixel_formats); ++i) {
        for (j = 0; j < SDL_arraysize(pixel_formats); ++j) {
            fmt1 = SDL_GetPixelFormatDetails(pixel_formats[i]);
            SDLTest_AssertCheck(fmt1 != NULL, "SDL_GetPixelFormatDetails(%s[0x%08" SDL_PRIx32 "]) should return a non-null pixel format",
                                SDL_GetPixelFormatName(pixel_formats[i]), pixel_formats[i]);
            cvt1 = SDL_ConvertSurface(face, fmt1->format);
            SDLTest_AssertCheck(cvt1 != NULL, "SDL_ConvertSurface(..., %s[0x%08" SDL_PRIx32 "]) should return a non-null surface",
                                SDL_GetPixelFormatName(pixel_formats[i]), pixel_formats[i]);

            fmt2 = SDL_GetPixelFormatDetails(pixel_formats[j]);
            SDLTest_AssertCheck(fmt2 != NULL, "SDL_GetPixelFormatDetails(%s[0x%08" SDL_PRIx32 "]) should return a non-null pixel format",
                                SDL_GetPixelFormatName(pixel_formats[i]), pixel_formats[i]);
            cvt2 = SDL_ConvertSurface(cvt1, fmt2->format);
            SDLTest_AssertCheck(cvt2 != NULL, "SDL_ConvertSurface(..., %s[0x%08" SDL_PRIx32 "]) should return a non-null surface",
                                SDL_GetPixelFormatName(pixel_formats[i]), pixel_formats[i]);

            if (fmt1 && fmt2 &&
                fmt1->bytes_per_pixel == SDL_BYTESPERPIXEL(face->format) &&
                fmt2->bytes_per_pixel == SDL_BYTESPERPIXEL(face->format) &&
                SDL_ISPIXELFORMAT_ALPHA(fmt1->format) == SDL_ISPIXELFORMAT_ALPHA(face->format) &&
                SDL_ISPIXELFORMAT_ALPHA(fmt2->format) == SDL_ISPIXELFORMAT_ALPHA(face->format)) {
                final = SDL_ConvertSurface(cvt2, face->format);
                SDL_assert(final != NULL);

                /* Compare surface. */
                ret = SDLTest_CompareSurfaces(face, final, 0);
                SDLTest_AssertCheck(ret == 0, "Validate result from SDLTest_CompareSurfaces, expected: 0, got: %i", ret);
                SDL_DestroySurface(final);
            }

            SDL_DestroySurface(cvt1);
            SDL_DestroySurface(cvt2);
        }
    }

    /* Clean up. */
    SDL_DestroySurface(face);

    return TEST_COMPLETED;
}

/**
 * Tests sprite loading. A failure case.
 */
static int surface_testLoadFailure(void *arg)
{
    SDL_Surface *face = SDL_LoadBMP("nonexistant.bmp");
    SDLTest_AssertCheck(face == NULL, "SDL_CreateLoadBmp");

    return TEST_COMPLETED;
}

/**
 * Tests some blitting routines.
 */
static int surface_testBlit(void *arg)
{
    /* Basic blitting */
    testBlitBlendMode(SDL_BLENDMODE_NONE);

    return TEST_COMPLETED;
}

/**
 * Tests some blitting routines with color mod
 */
static int surface_testBlitColorMod(void *arg)
{
    /* Basic blitting with color mod */
    testBlitBlendMode(-1);

    return TEST_COMPLETED;
}

/**
 * Tests some blitting routines with alpha mod
 */
static int surface_testBlitAlphaMod(void *arg)
{
    /* Basic blitting with alpha mod */
    testBlitBlendMode(-2);

    return TEST_COMPLETED;
}

/**
 * Tests some more blitting routines.
 */
static int surface_testBlitBlendBlend(void *arg)
{
    /* Blend blitting */
    testBlitBlendMode(SDL_BLENDMODE_BLEND);

    return TEST_COMPLETED;
}

/**
 * @brief Tests some more blitting routines.
 */
static int surface_testBlitBlendPremultiplied(void *arg)
{
   /* Blend premultiplied blitting */
   testBlitBlendMode(SDL_BLENDMODE_BLEND_PREMULTIPLIED);

   return TEST_COMPLETED;
}

/**
 * Tests some more blitting routines.
 */
static int surface_testBlitBlendAdd(void *arg)
{
    /* Add blitting */
    testBlitBlendMode(SDL_BLENDMODE_ADD);

    return TEST_COMPLETED;
}

/**
 * Tests some more blitting routines.
 */
static int surface_testBlitBlendAddPremultiplied(void *arg)
{
    /* Add premultiplied blitting */
    testBlitBlendMode(SDL_BLENDMODE_ADD_PREMULTIPLIED);

    return TEST_COMPLETED;
}

/**
 * Tests some more blitting routines.
 */
static int surface_testBlitBlendMod(void *arg)
{
    /* Mod blitting */
    testBlitBlendMode(SDL_BLENDMODE_MOD);

    return TEST_COMPLETED;
}

/**
 * Tests some more blitting routines.
 */
static int surface_testBlitBlendMul(void *arg)
{
    /* Mod blitting */
    testBlitBlendMode(SDL_BLENDMODE_MUL);

    return TEST_COMPLETED;
}

static int surface_testOverflow(void *arg)
{
    char buf[1024];
    const char *expectedError;
    SDL_Surface *surface;

    SDL_memset(buf, '\0', sizeof(buf));

    expectedError = "Parameter 'width' is invalid";
    surface = SDL_CreateSurface(-3, 100, SDL_PIXELFORMAT_INDEX8);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative width");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(-1, 1, SDL_PIXELFORMAT_INDEX8, buf, 4);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative width");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(-1, 1, SDL_PIXELFORMAT_RGBA8888, buf, 4);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative width");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    expectedError = "Parameter 'height' is invalid";
    surface = SDL_CreateSurface(100, -3, SDL_PIXELFORMAT_INDEX8);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative height");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(1, -1, SDL_PIXELFORMAT_INDEX8, buf, 4);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative height");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(1, -1, SDL_PIXELFORMAT_RGBA8888, buf, 4);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative height");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    expectedError = "Parameter 'pitch' is invalid";
    surface = SDL_CreateSurfaceFrom(4, 1, SDL_PIXELFORMAT_INDEX8, buf, -1);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative pitch");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(1, 1, SDL_PIXELFORMAT_RGBA8888, buf, -1);
    SDLTest_AssertCheck(surface == NULL, "Should detect negative pitch");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(1, 1, SDL_PIXELFORMAT_RGBA8888, buf, 0);
    SDLTest_AssertCheck(surface == NULL, "Should detect zero pitch");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(1, 1, SDL_PIXELFORMAT_RGBA8888, NULL, 0);
    SDLTest_AssertCheck(surface != NULL, "Allow zero pitch for partially set up surfaces: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    /* Less than 1 byte per pixel: the pitch can legitimately be less than
     * the width, but it must be enough to hold the appropriate number of
     * bits per pixel. SDL_PIXELFORMAT_INDEX4* needs 1 byte per 2 pixels. */
    surface = SDL_CreateSurfaceFrom(6, 1, SDL_PIXELFORMAT_INDEX4LSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "6px * 4 bits per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(6, 1, SDL_PIXELFORMAT_INDEX4MSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "6px * 4 bits per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    surface = SDL_CreateSurfaceFrom(7, 1, SDL_PIXELFORMAT_INDEX4LSB, buf, 3);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(7, 1, SDL_PIXELFORMAT_INDEX4MSB, buf, 3);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    surface = SDL_CreateSurfaceFrom(7, 1, SDL_PIXELFORMAT_INDEX4LSB, buf, 4);
    SDLTest_AssertCheck(surface != NULL, "7px * 4 bits per px fits in 4 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(7, 1, SDL_PIXELFORMAT_INDEX4MSB, buf, 4);
    SDLTest_AssertCheck(surface != NULL, "7px * 4 bits per px fits in 4 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    /* SDL_PIXELFORMAT_INDEX2* needs 1 byte per 4 pixels. */
    surface = SDL_CreateSurfaceFrom(12, 1, SDL_PIXELFORMAT_INDEX2LSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "12px * 2 bits per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(12, 1, SDL_PIXELFORMAT_INDEX2MSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "12px * 2 bits per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    surface = SDL_CreateSurfaceFrom(13, 1, SDL_PIXELFORMAT_INDEX2LSB, buf, 3);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp (%d)", surface ? surface->pitch : 0);
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(13, 1, SDL_PIXELFORMAT_INDEX2MSB, buf, 3);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    surface = SDL_CreateSurfaceFrom(13, 1, SDL_PIXELFORMAT_INDEX2LSB, buf, 4);
    SDLTest_AssertCheck(surface != NULL, "13px * 2 bits per px fits in 4 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(13, 1, SDL_PIXELFORMAT_INDEX2MSB, buf, 4);
    SDLTest_AssertCheck(surface != NULL, "13px * 2 bits per px fits in 4 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    /* SDL_PIXELFORMAT_INDEX1* needs 1 byte per 8 pixels. */
    surface = SDL_CreateSurfaceFrom(16, 1, SDL_PIXELFORMAT_INDEX1LSB, buf, 2);
    SDLTest_AssertCheck(surface != NULL, "16px * 1 bit per px fits in 2 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(16, 1, SDL_PIXELFORMAT_INDEX1MSB, buf, 2);
    SDLTest_AssertCheck(surface != NULL, "16px * 1 bit per px fits in 2 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    surface = SDL_CreateSurfaceFrom(17, 1, SDL_PIXELFORMAT_INDEX1LSB, buf, 2);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(17, 1, SDL_PIXELFORMAT_INDEX1MSB, buf, 2);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    surface = SDL_CreateSurfaceFrom(17, 1, SDL_PIXELFORMAT_INDEX1LSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "17px * 1 bit per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(17, 1, SDL_PIXELFORMAT_INDEX1MSB, buf, 3);
    SDLTest_AssertCheck(surface != NULL, "17px * 1 bit per px fits in 3 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    /* SDL_PIXELFORMAT_INDEX8 and SDL_PIXELFORMAT_RGB332 require 1 byte per pixel. */
    surface = SDL_CreateSurfaceFrom(5, 1, SDL_PIXELFORMAT_RGB332, buf, 5);
    SDLTest_AssertCheck(surface != NULL, "5px * 8 bits per px fits in 5 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(5, 1, SDL_PIXELFORMAT_INDEX8, buf, 5);
    SDLTest_AssertCheck(surface != NULL, "5px * 8 bits per px fits in 5 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    surface = SDL_CreateSurfaceFrom(6, 1, SDL_PIXELFORMAT_RGB332, buf, 5);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(6, 1, SDL_PIXELFORMAT_INDEX8, buf, 5);
    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    /* Everything else requires more than 1 byte per pixel, and rounds up
     * each pixel to an integer number of bytes (e.g. RGB555 is really
     * XRGB1555, with 1 bit per pixel wasted). */
    surface = SDL_CreateSurfaceFrom(3, 1, SDL_PIXELFORMAT_XRGB1555, buf, 6);
    SDLTest_AssertCheck(surface != NULL, "3px * 15 (really 16) bits per px fits in 6 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);
    surface = SDL_CreateSurfaceFrom(3, 1, SDL_PIXELFORMAT_XRGB1555, buf, 6);
    SDLTest_AssertCheck(surface != NULL, "5px * 15 (really 16) bits per px fits in 6 bytes: %s",
                        surface != NULL ? "(success)" : SDL_GetError());
    SDL_DestroySurface(surface);

    surface = SDL_CreateSurfaceFrom(4, 1, SDL_PIXELFORMAT_XRGB1555, buf, 6);
    SDLTest_AssertCheck(surface == NULL, "4px * 15 (really 16) bits per px doesn't fit in 6 bytes");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    surface = SDL_CreateSurfaceFrom(4, 1, SDL_PIXELFORMAT_XRGB1555, buf, 6);
    SDLTest_AssertCheck(surface == NULL, "4px * 15 (really 16) bits per px doesn't fit in 6 bytes");
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    if (sizeof(size_t) == 4 && sizeof(int) >= 4) {
        SDL_ClearError();
        expectedError = "aligning pitch would overflow";
        /* 0x5555'5555 * 3bpp = 0xffff'ffff which fits in size_t, but adding
         * alignment padding makes it overflow */
        surface = SDL_CreateSurface(0x55555555, 1, SDL_PIXELFORMAT_RGB24);
        SDLTest_AssertCheck(surface == NULL, "Should detect overflow in pitch + alignment");
        SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                            "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
        SDL_ClearError();
        expectedError = "width * bpp would overflow";
        /* 0x4000'0000 * 4bpp = 0x1'0000'0000 which (just) overflows */
        surface = SDL_CreateSurface(0x40000000, 1, SDL_PIXELFORMAT_ARGB8888);
        SDLTest_AssertCheck(surface == NULL, "Should detect overflow in width * bytes per pixel");
        SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                            "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
        SDL_ClearError();
        expectedError = "height * pitch would overflow";
        surface = SDL_CreateSurface((1 << 29) - 1, (1 << 29) - 1, SDL_PIXELFORMAT_INDEX8);
        SDLTest_AssertCheck(surface == NULL, "Should detect overflow in width * height");
        SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                            "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
        SDL_ClearError();
        expectedError = "height * pitch would overflow";
        surface = SDL_CreateSurface((1 << 15) + 1, (1 << 15) + 1, SDL_PIXELFORMAT_ARGB8888);
        SDLTest_AssertCheck(surface == NULL, "Should detect overflow in width * height * bytes per pixel");
        SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                            "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
    } else {
        SDLTest_Log("Can't easily overflow size_t on this platform");
    }

    return TEST_COMPLETED;
}

static int surface_testFlip(void *arg)
{
    SDL_Surface *surface;
    Uint8 *pixels;
    int offset;
    const char *expectedError;

    surface = SDL_CreateSurface(3, 3, SDL_PIXELFORMAT_RGB24);
    SDLTest_AssertCheck(surface != NULL, "SDL_CreateSurface()");

    SDL_ClearError();
    expectedError = "Parameter 'surface' is invalid";
    SDL_FlipSurface(NULL, SDL_FLIP_HORIZONTAL);
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    SDL_ClearError();
    expectedError = "Parameter 'flip' is invalid";
    SDL_FlipSurface(surface, SDL_FLIP_NONE);
    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());

    pixels = (Uint8 *)surface->pixels;
    *pixels = 0xFF;
    offset = 0;

    SDLTest_AssertPass("Call to SDL_FlipSurface(surface, SDL_FLIP_VERTICAL)");
    CHECK_FUNC(SDL_FlipSurface, (surface, SDL_FLIP_VERTICAL));
    SDLTest_AssertCheck(pixels[offset] == 0x00,
                        "Expected pixels[%d] == 0x00 got 0x%.2X", offset, pixels[offset]);
    offset = 2 * surface->pitch;
    SDLTest_AssertCheck(pixels[offset] == 0xFF,
                        "Expected pixels[%d] == 0xFF got 0x%.2X", offset, pixels[offset]);

    SDLTest_AssertPass("Call to SDL_FlipSurface(surface, SDL_FLIP_HORIZONTAL)");
    CHECK_FUNC(SDL_FlipSurface, (surface, SDL_FLIP_HORIZONTAL));
    SDLTest_AssertCheck(pixels[offset] == 0x00,
                        "Expected pixels[%d] == 0x00 got 0x%.2X", offset, pixels[offset]);
    offset += (surface->w - 1) * SDL_BYTESPERPIXEL(surface->format);
    SDLTest_AssertCheck(pixels[offset] == 0xFF,
                        "Expected pixels[%d] == 0xFF got 0x%.2X", offset, pixels[offset]);

    SDL_DestroySurface(surface);

    return TEST_COMPLETED;
}

static int surface_testPalette(void *arg)
{
    SDL_Surface *source, *surface, *output;
    SDL_Palette *palette;
    Uint8 *pixels;

    palette = SDL_CreatePalette(2);
    SDLTest_AssertCheck(palette != NULL, "SDL_CreatePalette()");

    source = SDL_CreateSurface(1, 1, SDL_PIXELFORMAT_INDEX8);
    SDLTest_AssertCheck(source != NULL, "SDL_CreateSurface()");
    SDLTest_AssertCheck(SDL_GetSurfacePalette(source) == NULL, "SDL_GetSurfacePalette(source)");

    surface = SDL_CreateSurface(1, 1, SDL_PIXELFORMAT_INDEX8);
    SDLTest_AssertCheck(surface != NULL, "SDL_CreateSurface()");
    SDLTest_AssertCheck(SDL_GetSurfacePalette(surface) == NULL, "SDL_GetSurfacePalette(surface)");

    pixels = (Uint8 *)surface->pixels;
    SDLTest_AssertCheck(*pixels == 0, "Expected *pixels == 0 got %u", *pixels);

    /* Identity copy between indexed surfaces without a palette */
    *(Uint8 *)source->pixels = 1;
    SDL_BlitSurface(source, NULL, surface, NULL);
    SDLTest_AssertCheck(*pixels == 1, "Expected *pixels == 1 got %u", *pixels);

    /* Identity copy between indexed surfaces where the destination has a palette */
    palette->colors[0].r = 0;
    palette->colors[0].g = 0;
    palette->colors[0].b = 0;
    palette->colors[1].r = 0xFF;
    palette->colors[1].g = 0;
    palette->colors[1].b = 0;
    SDL_SetSurfacePalette(surface, palette);
    *pixels = 0;
    SDL_BlitSurface(source, NULL, surface, NULL);
    SDLTest_AssertCheck(*pixels == 1, "Expected *pixels == 1 got %u", *pixels);

    output = SDL_CreateSurface(1, 1, SDL_PIXELFORMAT_RGBA32);
    SDLTest_AssertCheck(output != NULL, "SDL_CreateSurface()");

    pixels = (Uint8 *)output->pixels;
    SDL_BlitSurface(surface, NULL, output, NULL);
    SDLTest_AssertCheck(*pixels == 0xFF, "Expected *pixels == 0xFF got 0x%.2X", *pixels);

    /* Set the palette color and blit again */
    palette->colors[1].r = 0xAA;
    SDL_SetSurfacePalette(surface, palette);
    SDL_BlitSurface(surface, NULL, output, NULL);
    SDLTest_AssertCheck(*pixels == 0xAA, "Expected *pixels == 0xAA got 0x%.2X", *pixels);

    SDL_DestroyPalette(palette);
    SDL_DestroySurface(source);
    SDL_DestroySurface(surface);
    SDL_DestroySurface(output);

    return TEST_COMPLETED;
}

static int surface_testClearSurface(void *arg)
{
    SDL_PixelFormat formats[] = {
        SDL_PIXELFORMAT_ARGB8888, SDL_PIXELFORMAT_RGBA8888,
        SDL_PIXELFORMAT_ARGB2101010, SDL_PIXELFORMAT_ABGR2101010,
        SDL_PIXELFORMAT_ARGB64, SDL_PIXELFORMAT_RGBA64,
        SDL_PIXELFORMAT_ARGB128_FLOAT, SDL_PIXELFORMAT_RGBA128_FLOAT,
        SDL_PIXELFORMAT_YV12, SDL_PIXELFORMAT_UYVY, SDL_PIXELFORMAT_NV12
    };
    SDL_Surface *surface;
    SDL_PixelFormat format;
    const float MAXIMUM_ERROR_RGB = 0.0001f;
    const float MAXIMUM_ERROR_YUV = 0.01f;
    float srcR = 10 / 255.0f, srcG = 128 / 255.0f, srcB = 240 / 255.0f, srcA = 1.0f;
    float actualR, actualG, actualB, actualA;
    float deltaR, deltaG, deltaB, deltaA;
    int i, ret;

    for (i = 0; i < SDL_arraysize(formats); ++i) {
        const float MAXIMUM_ERROR = SDL_ISPIXELFORMAT_FOURCC(formats[i]) ? MAXIMUM_ERROR_YUV : MAXIMUM_ERROR_RGB;

        format = formats[i];

        surface = SDL_CreateSurface(1, 1, format);
        SDLTest_AssertCheck(surface != NULL, "SDL_CreateSurface()");
        ret = SDL_ClearSurface(surface, srcR, srcG, srcB, srcA);
        SDLTest_AssertCheck(ret == 0, "SDL_ClearSurface()");
        ret = SDL_ReadSurfacePixelFloat(surface, 0, 0, &actualR, &actualG, &actualB, &actualA);
        SDLTest_AssertCheck(ret == 0, "SDL_ReadSurfacePixelFloat()");
        deltaR = SDL_fabsf(actualR - srcR);
        deltaG = SDL_fabsf(actualG - srcG);
        deltaB = SDL_fabsf(actualB - srcB);
        deltaA = SDL_fabsf(actualA - srcA);
        SDLTest_AssertCheck(
            deltaR <= MAXIMUM_ERROR &&
            deltaG <= MAXIMUM_ERROR &&
            deltaB <= MAXIMUM_ERROR &&
            deltaA <= MAXIMUM_ERROR,
            "Checking %s surface clear results, expected %.4f,%.4f,%.4f,%.4f, got %.4f,%.4f,%.4f,%.4f",
            SDL_GetPixelFormatName(format),
            srcR, srcG, srcB, srcA, actualR, actualG, actualB, actualA);

        SDL_DestroySurface(surface);
    }

    return TEST_COMPLETED;
}

static int surface_testPremultiplyAlpha(void *arg)
{
    SDL_PixelFormat formats[] = {
        SDL_PIXELFORMAT_ARGB8888, SDL_PIXELFORMAT_RGBA8888,
        SDL_PIXELFORMAT_ARGB2101010, SDL_PIXELFORMAT_ABGR2101010,
        SDL_PIXELFORMAT_ARGB64, SDL_PIXELFORMAT_RGBA64,
        SDL_PIXELFORMAT_ARGB128_FLOAT, SDL_PIXELFORMAT_RGBA128_FLOAT,
    };
    SDL_Surface *surface;
    SDL_PixelFormat format;
    const float MAXIMUM_ERROR_LOW_PRECISION = 1 / 255.0f;
    const float MAXIMUM_ERROR_HIGH_PRECISION = 0.0001f;
    float srcR = 10 / 255.0f, srcG = 128 / 255.0f, srcB = 240 / 255.0f, srcA = 170 / 255.0f;
    float expectedR = srcR * srcA;
    float expectedG = srcG * srcA;
    float expectedB = srcB * srcA;
    float actualR, actualG, actualB;
    float deltaR, deltaG, deltaB;
    int i, ret;

    for (i = 0; i < SDL_arraysize(formats); ++i) {
        const float MAXIMUM_ERROR = (SDL_BITSPERPIXEL(formats[i]) > 32) ? MAXIMUM_ERROR_HIGH_PRECISION : MAXIMUM_ERROR_LOW_PRECISION;

        format = formats[i];

        surface = SDL_CreateSurface(1, 1, format);
        SDLTest_AssertCheck(surface != NULL, "SDL_CreateSurface()");
        ret = SDL_SetSurfaceColorspace(surface, SDL_COLORSPACE_SRGB);
        SDLTest_AssertCheck(ret == 0, "SDL_SetSurfaceColorspace()");
        ret = SDL_ClearSurface(surface, srcR, srcG, srcB, srcA);
        SDLTest_AssertCheck(ret == 0, "SDL_ClearSurface()");
        ret = SDL_PremultiplySurfaceAlpha(surface, SDL_FALSE);
        SDLTest_AssertCheck(ret == 0, "SDL_PremultiplySurfaceAlpha()");
        ret = SDL_ReadSurfacePixelFloat(surface, 0, 0, &actualR, &actualG, &actualB, NULL);
        SDLTest_AssertCheck(ret == 0, "SDL_ReadSurfacePixelFloat()");
        deltaR = SDL_fabsf(actualR - expectedR);
        deltaG = SDL_fabsf(actualG - expectedG);
        deltaB = SDL_fabsf(actualB - expectedB);
        SDLTest_AssertCheck(
            deltaR <= MAXIMUM_ERROR &&
            deltaG <= MAXIMUM_ERROR &&
            deltaB <= MAXIMUM_ERROR,
            "Checking %s alpha premultiply results, expected %.4f,%.4f,%.4f, got %.4f,%.4f,%.4f",
            SDL_GetPixelFormatName(format),
            expectedR, expectedG, expectedB, actualR, actualG, actualB);

        SDL_DestroySurface(surface);
    }

    return TEST_COMPLETED;
}


/* ================= Test References ================== */

/* Surface test cases */
static const SDLTest_TestCaseReference surfaceTestSaveLoadBitmap = {
    (SDLTest_TestCaseFp)surface_testSaveLoadBitmap, "surface_testSaveLoadBitmap", "Tests sprite saving and loading.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlit = {
    (SDLTest_TestCaseFp)surface_testBlit, "surface_testBlit", "Tests basic blitting.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitTiled = {
    (SDLTest_TestCaseFp)surface_testBlitTiled, "surface_testBlitTiled", "Tests tiled blitting.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlit9Grid = {
    (SDLTest_TestCaseFp)surface_testBlit9Grid, "surface_testBlit9Grid", "Tests 9-grid blitting.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestLoadFailure = {
    (SDLTest_TestCaseFp)surface_testLoadFailure, "surface_testLoadFailure", "Tests sprite loading. A failure case.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestSurfaceConversion = {
    (SDLTest_TestCaseFp)surface_testSurfaceConversion, "surface_testSurfaceConversion", "Tests surface conversion.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestCompleteSurfaceConversion = {
    (SDLTest_TestCaseFp)surface_testCompleteSurfaceConversion, "surface_testCompleteSurfaceConversion", "Tests surface conversion across all pixel formats", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitColorMod = {
    (SDLTest_TestCaseFp)surface_testBlitColorMod, "surface_testBlitColorMod", "Tests some blitting routines with color mod.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitAlphaMod = {
    (SDLTest_TestCaseFp)surface_testBlitAlphaMod, "surface_testBlitAlphaMod", "Tests some blitting routines with alpha mod.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendBlend = {
    (SDLTest_TestCaseFp)surface_testBlitBlendBlend, "surface_testBlitBlendBlend", "Tests blitting routines with blend blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendPremultiplied = {
    (SDLTest_TestCaseFp)surface_testBlitBlendPremultiplied, "surface_testBlitBlendPremultiplied", "Tests blitting routines with premultiplied blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendAdd = {
    (SDLTest_TestCaseFp)surface_testBlitBlendAdd, "surface_testBlitBlendAdd", "Tests blitting routines with add blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendAddPremultiplied = {
    (SDLTest_TestCaseFp)surface_testBlitBlendAddPremultiplied, "surface_testBlitBlendAddPremultiplied", "Tests blitting routines with premultiplied add blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendMod = {
    (SDLTest_TestCaseFp)surface_testBlitBlendMod, "surface_testBlitBlendMod", "Tests blitting routines with mod blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestBlitBlendMul = {
    (SDLTest_TestCaseFp)surface_testBlitBlendMul, "surface_testBlitBlendMul", "Tests blitting routines with mul blending mode.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestOverflow = {
    surface_testOverflow, "surface_testOverflow", "Test overflow detection.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestFlip = {
    surface_testFlip, "surface_testFlip", "Test surface flipping.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestPalette = {
    surface_testPalette, "surface_testPalette", "Test surface palette operations.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestClearSurface = {
    surface_testClearSurface, "surface_testClearSurface", "Test clear surface operations.", TEST_ENABLED
};

static const SDLTest_TestCaseReference surfaceTestPremultiplyAlpha = {
    surface_testPremultiplyAlpha, "surface_testPremultiplyAlpha", "Test alpha premultiply operations.", TEST_ENABLED
};

/* Sequence of Surface test cases */
static const SDLTest_TestCaseReference *surfaceTests[] = {
    &surfaceTestSaveLoadBitmap,
    &surfaceTestBlit,
    &surfaceTestBlitTiled,
    &surfaceTestBlit9Grid,
    &surfaceTestLoadFailure,
    &surfaceTestSurfaceConversion,
    &surfaceTestCompleteSurfaceConversion,
    &surfaceTestBlitColorMod,
    &surfaceTestBlitAlphaMod,
    &surfaceTestBlitBlendBlend,
    &surfaceTestBlitBlendPremultiplied,
    &surfaceTestBlitBlendAdd,
    &surfaceTestBlitBlendAddPremultiplied,
    &surfaceTestBlitBlendMod,
    &surfaceTestBlitBlendMul,
    &surfaceTestOverflow,
    &surfaceTestFlip,
    &surfaceTestPalette,
    &surfaceTestClearSurface,
    &surfaceTestPremultiplyAlpha,
    NULL
};

/* Surface test suite (global) */
SDLTest_TestSuiteReference surfaceTestSuite = {
    "Surface",
    surfaceSetUp,
    surfaceTests,
    surfaceTearDown

};