Commit 75ffa24e3a87789105a2f01915a8979694c371a7
2022-02-15T13:35:59
Software Render Jitter in rotation (bug #5143) The output surface doesn't necessarily to have even width and height.
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diff --git a/src/render/software/SDL_rotate.c b/src/render/software/SDL_rotate.c
index b5ac715..cd73bcd 100644
--- a/src/render/software/SDL_rotate.c
+++ b/src/render/software/SDL_rotate.c
@@ -128,26 +128,26 @@ SDLgfx_rotozoomSurfaceSizeTrig(int width, int height, double angle,
} else {
double x, y, cx, cy, sx, sy;
double radangle;
- int dstwidthhalf, dstheighthalf;
+ double dstwidth_max, dstheight_max;
/*
* Determine destination width and height by rotating a centered source box
*/
radangle = angle * (M_PI / -180.0); /* reverse the angle because our rotations are clockwise */
*sangle = SDL_sin(radangle);
*cangle = SDL_cos(radangle);
- x = (double)(width / 2);
- y = (double)(height / 2);
+ x = (double)width;
+ y = (double)height;
cx = *cangle * x;
cy = *cangle * y;
sx = *sangle * x;
sy = *sangle * y;
- dstwidthhalf = MAX((int)
- SDL_ceil(MAX(MAX(MAX(SDL_fabs(cx + sy), SDL_fabs(cx - sy)), SDL_fabs(-cx + sy)), SDL_fabs(-cx - sy))), 1);
- dstheighthalf = MAX((int)
- SDL_ceil(MAX(MAX(MAX(SDL_fabs(sx + cy), SDL_fabs(sx - cy)), SDL_fabs(-sx + cy)), SDL_fabs(-sx - cy))), 1);
- *dstwidth = 2 * dstwidthhalf;
- *dstheight = 2 * dstheighthalf;
+ dstwidth_max = MAX(
+ MAX(MAX(MAX(SDL_fabs(cx + sy), SDL_fabs(cx - sy)), SDL_fabs(-cx + sy)), SDL_fabs(-cx - sy)), 1);
+ dstheight_max = MAX(
+ MAX(MAX(MAX(SDL_fabs(sx + cy), SDL_fabs(sx - cy)), SDL_fabs(-sx + cy)), SDL_fabs(-sx - cy)), 1);
+ *dstwidth = SDL_round(dstwidth_max);
+ *dstheight = SDL_round(dstheight_max);
}
}