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| author | Colin Snover | 2017-11-19 12:24:01 -0600 |
|---|---|---|
| committer | Colin Snover | 2017-12-01 19:22:19 -0600 |
| commit | 9a36870e78cd678842384d1beadc74115d9c232d (patch) | |
| tree | b167b7859dfc16f3d761b50a0bf39a43b53f0cda /engines/scumm | |
| parent | 57db3f7535458504f308ea76e87167cf7ee95371 (diff) | |
| download | scummvm-rg350-9a36870e78cd678842384d1beadc74115d9c232d.tar.gz scummvm-rg350-9a36870e78cd678842384d1beadc74115d9c232d.tar.bz2 scummvm-rg350-9a36870e78cd678842384d1beadc74115d9c232d.zip | |
SCUMM HE: Fix UB shifting negative integers
Diffstat (limited to 'engines/scumm')
| -rw-r--r-- | engines/scumm/he/wiz_he.cpp | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/engines/scumm/he/wiz_he.cpp b/engines/scumm/he/wiz_he.cpp index 9339318d19..2db57022fd 100644 --- a/engines/scumm/he/wiz_he.cpp +++ b/engines/scumm/he/wiz_he.cpp @@ -1865,21 +1865,21 @@ struct PolygonDrawData { } void transform(const Common::Point *tp1, const Common::Point *tp2, const Common::Point *sp1, const Common::Point *sp2) { - int32 tx_acc = tp1->x << 16; - int32 sx_acc = sp1->x << 16; - int32 sy_acc = sp1->y << 16; + int32 tx_acc = tp1->x * (1 << 16); + int32 sx_acc = sp1->x * (1 << 16); + int32 sy_acc = sp1->y * (1 << 16); uint16 dy = ABS(tp2->y - tp1->y) + 1; - int32 tx_step = ((tp2->x - tp1->x) << 16) / dy; - int32 sx_step = ((sp2->x - sp1->x) << 16) / dy; - int32 sy_step = ((sp2->y - sp1->y) << 16) / dy; + int32 tx_step = ((tp2->x - tp1->x) * (1 << 16)) / dy; + int32 sx_step = ((sp2->x - sp1->x) * (1 << 16)) / dy; + int32 sy_step = ((sp2->y - sp1->y) * (1 << 16)) / dy; int y = tp1->y - mat[0].y; while (dy--) { assert(y >= 0 && y < pAreasNum); PolygonArea *ppa = &pa[y]; - int32 ttx = tx_acc >> 16; - int32 tsx = sx_acc >> 16; - int32 tsy = sy_acc >> 16; + int32 ttx = tx_acc / (1 << 16); + int32 tsx = sx_acc / (1 << 16); + int32 tsy = sy_acc / (1 << 16); if (ppa->xmin > ttx) { ppa->xmin = ttx; @@ -2143,12 +2143,12 @@ void Wiz::drawWizPolygonImage(uint8 *dst, const uint8 *src, const uint8 *mask, i int16 w = x2 - x1 + 1; if (w > 0) { int16 width = ppa->xmax - ppa->xmin + 1; - pra->x_step = ((ppa->x2 - ppa->x1) << 16) / width; - pra->y_step = ((ppa->y2 - ppa->y1) << 16) / width; + pra->x_step = ((ppa->x2 - ppa->x1) * (1 << 16)) / width; + pra->y_step = ((ppa->y2 - ppa->y1) * (1 << 16)) / width; pra->dst_offs = yoff + x1 * _vm->_bytesPerPixel; pra->w = w; - pra->x_s = ppa->x1 << 16; - pra->y_s = ppa->y1 << 16; + pra->x_s = ppa->x1 * (1 << 16); + pra->y_s = ppa->y1 * (1 << 16); int16 tmp = x1 - ppa->xmin; if (tmp != 0) { pra->x_s += pra->x_step * tmp; @@ -2170,7 +2170,7 @@ void Wiz::drawWizPolygonImage(uint8 *dst, const uint8 *src, const uint8 *mask, i int32 x_acc = pra->x_s; int32 y_acc = pra->y_s; while (--w) { - int32 src_offs = (y_acc >> 16) * wizW + (x_acc >> 16); + int32 src_offs = (y_acc / (1 << 16)) * wizW + (x_acc / (1 << 16)); assert(src_offs < wizW * wizH); x_acc += pra->x_step; y_acc += pra->y_step; |