diff options
Diffstat (limited to 'src/GPU3D_Soft.cpp')
| -rw-r--r-- | src/GPU3D_Soft.cpp | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/src/GPU3D_Soft.cpp b/src/GPU3D_Soft.cpp index e7cf542..b377b73 100644 --- a/src/GPU3D_Soft.cpp +++ b/src/GPU3D_Soft.cpp @@ -199,20 +199,44 @@ public: { if (xdiff == 0) return y0; + s32 ybase, ydiff; + if (y1 < y0) + { + ybase = y0; + ydiff = y1 - y0 - 1; + } + else + { + ybase = y0; + ydiff = y1 - y0; + } + if (wdiff != 0) - return y0 + (((y1 - y0) * yfactor) >> shift); + return ybase + ((ydiff * yfactor) >> shift); else - return y0 + (((y1 - y0) * x) / xdiff); + return ybase + ((ydiff * x) / xdiff); } s32 InterpolateZ(s32 z0, s32 z1, bool wbuffer) { if (xdiff == 0) return z0; + s32 zbase, zdiff; + if (z1 < z0) + { + zbase = z0; + zdiff = z1 - z0 - 1; + } + else + { + zbase = z0; + zdiff = z1 - z0; + } + if ((wdiff != 0) && wbuffer) - return z0 + (((s64)(z1 - z0) * yfactor) >> shift); + return zbase + (((s64)zdiff * yfactor) >> shift); else - return z0 + (((s64)(z1 - z0) * x) / xdiff); + return zbase + (((s64)zdiff * x) / xdiff); } private: |