added simple affine check to accelerate texture fetches on 2D art

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@11017 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/dpsoftrast.c b/dpsoftrast.c
index a784374e8773c55d8392d952875a2602a67ef024..b0a5a3ad50f9651fa3a5849c6a634f053a3b76de 100644 (file)
--- a/dpsoftrast.c
+++ b/dpsoftrast.c
@@ -2626,6 +2626,7 @@ void DPSOFTRAST_Draw_Span_Texture2DVaryingBGRA8(DPSOFTRAST_State_Thread *thread,
        __m128i subtc, substep, endsubtc;
        int filter;
        int mip;
+       int affine; // LordHavoc: optimized affine texturing case
        unsigned int * RESTRICT outi = (unsigned int *)out4ub;
        const unsigned char * RESTRICT pixelbase;
        DPSOFTRAST_Texture *texture = thread->texbound[texunitindex];
@@ -2645,6 +2646,7 @@ void DPSOFTRAST_Draw_Span_Texture2DVaryingBGRA8(DPSOFTRAST_State_Thread *thread,
                        outi[x] = k;
                return;
        }
+       affine = zf[startx] == zf[endx-1];
        filter = texture->filter & DPSOFTRAST_TEXTURE_FILTER_LINEAR;
        DPSOFTRAST_CALCATTRIB(triangle, span, data, slope, arrayindex);
        flags = texture->flags;
@@ -2663,7 +2665,7 @@ void DPSOFTRAST_Draw_Span_Texture2DVaryingBGRA8(DPSOFTRAST_State_Thread *thread,
        {
                int nextsub = x + DPSOFTRAST_DRAW_MAXSUBSPAN, endsub = nextsub - 1;
                __m128 subscale = _mm_set1_ps(65536.0f/DPSOFTRAST_DRAW_MAXSUBSPAN);
-               if (nextsub >= endx)
+               if (nextsub >= endx || affine)
                {
                        nextsub = endsub = endx-1;
                        if (x < nextsub) subscale = _mm_set1_ps(65536.0f / (nextsub - x));