diff options
| -rw-r--r-- | src/GPU3D_Soft.h | 41 |
1 files changed, 12 insertions, 29 deletions
diff --git a/src/GPU3D_Soft.h b/src/GPU3D_Soft.h index c792f13..25a2d6c 100644 --- a/src/GPU3D_Soft.h +++ b/src/GPU3D_Soft.h @@ -78,13 +78,12 @@ private: this->x1 = x1; this->xdiff = x1 - x0; - // calculate reciprocals for linear mode and Z interpolation + // calculate reciprocal for Z interpolation // TODO eventually: use a faster reciprocal function? if (this->xdiff != 0) - this->xrecip = (1<<30) / this->xdiff; + this->xrecip_z = (1<<22) / this->xdiff; else - this->xrecip = 0; - this->xrecip_z = this->xrecip >> 8; + this->xrecip_z = 0; // linear mode is used if both W values are equal and have // low-order bits cleared (0-6 along X, 1-6 along Y) @@ -156,11 +155,10 @@ private: else { // linear interpolation - // checkme: the rounding bias there (3<<24) is a guess if (y0 < y1) - return y0 + ((((s64)(y1-y0) * x * xrecip) + (3<<24)) >> 30); + return y0 + (s64)(y1-y0) * x / xdiff; else - return y1 + ((((s64)(y0-y1) * (xdiff-x) * xrecip) + (3<<24)) >> 30); + return y1 + (s64)(y0-y1) * (xdiff - x) / xdiff; } } @@ -220,7 +218,7 @@ private: int shift; bool linear; - s32 xrecip, xrecip_z; + s32 xrecip_z; s32 w0n, w0d, w1d; u32 yfactor; @@ -326,20 +324,12 @@ private: s32 x = XVal(); - if (XMajor) - { - if (side) Interp.Setup(x0-1, x1-1, w0, w1); // checkme - else Interp.Setup(x0, x1, w0, w1); - Interp.SetX(x); + int interpoffset = (Increment >= 0x40000) && (side ^ Negative); + Interp.Setup(y0-interpoffset, y1-interpoffset, w0, w1); + Interp.SetX(y); - // used for calculating AA coverage - xcov_incr = (ylen << 10) / xlen; - } - else - { - Interp.Setup(y0, y1, w0, w1); - Interp.SetX(y); - } + // used for calculating AA coverage + if (XMajor) xcov_incr = (ylen << 10) / xlen; return x; } @@ -350,14 +340,7 @@ private: y++; s32 x = XVal(); - if (XMajor) - { - Interp.SetX(x); - } - else - { - Interp.SetX(y); - } + Interp.SetX(y); return x; } |