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Fixed #5143 - software Render Jitter in rotation

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better precision calculating rotated coordinates and interpolation
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Sylvain 2022-02-17 23:11:02 +01:00
parent 18032979d8
commit ceb09ee740
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GPG key ID: 5F87E02E5BC0939E
3 changed files with 123 additions and 114 deletions
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53
src/render/software/SDL_render_sw.c
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@ -435,59 +435,32 @@ SW_RenderCopyEx(SDL_Renderer * renderer, SDL_Surface *surface, SDL_Texture * tex
SDL_SetSurfaceBlendMode(src_clone, blendmode);
if (!retval) {
int dstwidth, dstheight;
SDL_Rect rect_dest;
double cangle, sangle;
SDLgfx_rotozoomSurfaceSizeTrig(tmp_rect.w, tmp_rect.h, angle, &dstwidth, &dstheight, &cangle, &sangle);
src_rotated = SDLgfx_rotateSurface(src_clone, angle, dstwidth/2, dstheight/2, (texture->scaleMode == SDL_ScaleModeNearest) ? 0 : 1, flip & SDL_FLIP_HORIZONTAL, flip & SDL_FLIP_VERTICAL, dstwidth, dstheight, cangle, sangle);
SDLgfx_rotozoomSurfaceSizeTrig(tmp_rect.w, tmp_rect.h, angle, center,
&rect_dest, &cangle, &sangle);
src_rotated = SDLgfx_rotateSurface(src_clone, angle,
(texture->scaleMode == SDL_ScaleModeNearest) ? 0 : 1, flip & SDL_FLIP_HORIZONTAL, flip & SDL_FLIP_VERTICAL,
&rect_dest, cangle, sangle, center);
if (src_rotated == NULL) {
retval = -1;
}
if (!retval && mask != NULL) {
/* The mask needed for the NONE blend mode gets rotated with the same parameters. */
mask_rotated = SDLgfx_rotateSurface(mask, angle, dstwidth/2, dstheight/2, SDL_FALSE, 0, 0, dstwidth, dstheight, cangle, sangle);
mask_rotated = SDLgfx_rotateSurface(mask, angle,
SDL_FALSE, 0, 0,
&rect_dest, cangle, sangle, center);
if (mask_rotated == NULL) {
retval = -1;
}
}
if (!retval) {
double abscenterx, abscentery;
double px, py, p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y;
/* Find out where the new origin is by rotating the four final_rect points around the center and then taking the extremes */
abscenterx = final_rect->x + center->x;
abscentery = final_rect->y + center->y;
/* Compensate the angle inversion to match the behaviour of the other backends */
sangle = -sangle;
/* Top Left */
px = final_rect->x - abscenterx;
py = final_rect->y - abscentery;
p1x = px * cangle - py * sangle + abscenterx;
p1y = px * sangle + py * cangle + abscentery;
/* Top Right */
px = final_rect->x + final_rect->w - abscenterx;
py = final_rect->y - abscentery;
p2x = px * cangle - py * sangle + abscenterx;
p2y = px * sangle + py * cangle + abscentery;
/* Bottom Left */
px = final_rect->x - abscenterx;
py = final_rect->y + final_rect->h - abscentery;
p3x = px * cangle - py * sangle + abscenterx;
p3y = px * sangle + py * cangle + abscentery;
/* Bottom Right */
px = final_rect->x + final_rect->w - abscenterx;
py = final_rect->y + final_rect->h - abscentery;
p4x = px * cangle - py * sangle + abscenterx;
p4y = px * sangle + py * cangle + abscentery;
tmp_rect.x = (int)MIN(MIN(p1x, p2x), MIN(p3x, p4x));
tmp_rect.y = (int)MIN(MIN(p1y, p2y), MIN(p3y, p4y));
tmp_rect.w = dstwidth;
tmp_rect.h = dstheight;
tmp_rect.x = final_rect->x + rect_dest.x;
tmp_rect.y = final_rect->y + rect_dest.y;
tmp_rect.w = rect_dest.w;
tmp_rect.h = rect_dest.h;
/* The NONE blend mode needs some special care with non-opaque surfaces.
* Other blend modes or opaque surfaces can be blitted directly.