From cadeec9cc93b9b825120987a49d657b38d90ed1f Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sat, 21 Dec 2024 06:16:10 -0800
Subject: [PATCH] SDL_SoftStretch() doesn't handle large pixel formats
Fixes https://github.com/libsdl-org/SDL/issues/11534
---
src/video/SDL_surface.c | 3 +-
test/testautomation_surface.c | 63 +++++++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+), 1 deletion(-)
diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index 71fa9ceb07cc2..f6e4f5e252a8f 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -1254,7 +1254,8 @@ bool SDL_BlitSurfaceUncheckedScaled(SDL_Surface *src, const SDL_Rect *srcrect, S
if (scaleMode == SDL_SCALEMODE_NEAREST) {
if (!(src->map.info.flags & complex_copy_flags) &&
src->format == dst->format &&
- !SDL_ISPIXELFORMAT_INDEXED(src->format)) {
+ !SDL_ISPIXELFORMAT_INDEXED(src->format) &&
+ SDL_BYTESPERPIXEL(src->format) <= 4) {
return SDL_SoftStretch(src, srcrect, dst, dstrect, SDL_SCALEMODE_NEAREST);
} else if (SDL_BITSPERPIXEL(src->format) < 8) {
// Scaling bitmap not yet supported, convert to RGBA for blit
diff --git a/test/testautomation_surface.c b/test/testautomation_surface.c
index 7ba11caac49b7..c1d641eef6331 100644
--- a/test/testautomation_surface.c
+++ b/test/testautomation_surface.c
@@ -1479,6 +1479,64 @@ static int SDLCALL surface_testPremultiplyAlpha(void *arg)
}
+static int SDLCALL surface_testScale(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_ScaleMode modes[] = {
+ SDL_SCALEMODE_NEAREST, SDL_SCALEMODE_LINEAR
+ };
+ SDL_Surface *surface, *result;
+ SDL_PixelFormat format;
+ SDL_ScaleMode mode;
+ const float MAXIMUM_ERROR = 0.0001f;
+ float srcR = 10 / 255.0f, srcG = 128 / 255.0f, srcB = 240 / 255.0f, srcA = 170 / 255.0f;
+ float actualR, actualG, actualB, actualA;
+ float deltaR, deltaG, deltaB, deltaA;
+ int i, j, ret;
+
+ for (i = 0; i < SDL_arraysize(formats); ++i) {
+ for (j = 0; j < SDL_arraysize(modes); ++j) {
+ format = formats[i];
+ mode = modes[j];
+
+ surface = SDL_CreateSurface(1, 1, format);
+ SDLTest_AssertCheck(surface != NULL, "SDL_CreateSurface()");
+ ret = SDL_SetSurfaceColorspace(surface, SDL_COLORSPACE_SRGB);
+ SDLTest_AssertCheck(ret == true, "SDL_SetSurfaceColorspace()");
+ ret = SDL_ClearSurface(surface, srcR, srcG, srcB, srcA);
+ SDLTest_AssertCheck(ret == true, "SDL_ClearSurface()");
+ result = SDL_ScaleSurface(surface, 2, 2, mode);
+ SDLTest_AssertCheck(ret == true, "SDL_PremultiplySurfaceAlpha()");
+ ret = SDL_ReadSurfacePixelFloat(result, 1, 1, &actualR, &actualG, &actualB, &actualA);
+ SDLTest_AssertCheck(ret == true, "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 %s scaling results, expected %.4f,%.4f,%.4f,%.4f got %.4f,%.4f,%.4f,%.4f",
+ SDL_GetPixelFormatName(format),
+ mode == SDL_SCALEMODE_NEAREST ? "nearest" : "linear",
+ srcR, srcG, srcB, srcA, actualR, actualG, actualB, actualA);
+
+ SDL_DestroySurface(surface);
+ SDL_DestroySurface(result);
+ }
+ }
+
+ return TEST_COMPLETED;
+}
+
+
/* ================= Test References ================== */
/* Surface test cases */
@@ -1574,6 +1632,10 @@ static const SDLTest_TestCaseReference surfaceTestPremultiplyAlpha = {
surface_testPremultiplyAlpha, "surface_testPremultiplyAlpha", "Test alpha premultiply operations.", TEST_ENABLED
};
+static const SDLTest_TestCaseReference surfaceTestScale = {
+ surface_testScale, "surface_testScale", "Test scaling operations.", TEST_ENABLED
+};
+
/* Sequence of Surface test cases */
static const SDLTest_TestCaseReference *surfaceTests[] = {
&surfaceTestSaveLoadBitmap,
@@ -1599,6 +1661,7 @@ static const SDLTest_TestCaseReference *surfaceTests[] = {
&surfaceTestPalettization,
&surfaceTestClearSurface,
&surfaceTestPremultiplyAlpha,
+ &surfaceTestScale,
NULL
};