Moved software rasterizer functionality to new directory.

1 files changed, 1191 insertions, 0 deletions

diff --git a/src/mesa/swrast/s_tritemp.h b/src/mesa/swrast/s_tritemp.h
new file mode 100644
index 00000000000..21e7ceef5af
--- /dev/null
+++ b/src/mesa/swrast/s_tritemp.h
@@ -0,0 +1,1191 @@
+/* $Id: s_tritemp.h,v 1.1 2000/10/31 18:00:04 keithw Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version:  3.5
+ * 
+ * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*
+ * Triangle Rasterizer Template
+ *
+ * This file is #include'd to generate custom triangle rasterizers.
+ *
+ * The following macros may be defined to indicate what auxillary information
+ * must be interplated across the triangle:
+ *    INTERP_Z        - if defined, interpolate Z values
+ *    INTERP_RGB      - if defined, interpolate RGB values
+ *    INTERP_SPEC     - if defined, interpolate specular RGB values
+ *    INTERP_ALPHA    - if defined, interpolate Alpha values
+ *    INTERP_INDEX    - if defined, interpolate color index values
+ *    INTERP_INT_TEX  - if defined, interpolate integer ST texcoords
+ *                         (fast, simple 2-D texture mapping)
+ *    INTERP_TEX      - if defined, interpolate set 0 float STRQ texcoords
+ *                         NOTE:  OpenGL STRQ = Mesa STUV (R was taken for red)
+ *    INTERP_MULTITEX - if defined, interpolate N units of STRQ texcoords
+ *
+ * When one can directly address pixels in the color buffer the following
+ * macros can be defined and used to compute pixel addresses during
+ * rasterization (see pRow):
+ *    PIXEL_TYPE          - the datatype of a pixel (GLubyte, GLushort, GLuint)
+ *    BYTES_PER_ROW       - number of bytes per row in the color buffer
+ *    PIXEL_ADDRESS(X,Y)  - returns the address of pixel at (X,Y) where
+ *                          Y==0 at bottom of screen and increases upward.
+ *
+ * Similarly, for direct depth buffer access, this type is used for depth
+ * buffer addressing:
+ *    DEPTH_TYPE          - either GLushort or GLuint
+ *
+ * Optionally, one may provide one-time setup code per triangle:
+ *    SETUP_CODE    - code which is to be executed once per triangle
+ * 
+ * The following macro MUST be defined:
+ *    INNER_LOOP(LEFT,RIGHT,Y) - code to write a span of pixels.
+ *        Something like:
+ *
+ *                    for (x=LEFT; x<RIGHT;x++) {
+ *                       put_pixel(x,Y);
+ *                       // increment fixed point interpolants
+ *                    }
+ *
+ * This code was designed for the origin to be in the lower-left corner.
+ *
+ * Inspired by triangle rasterizer code written by Allen Akin.  Thanks Allen!
+ */
+
+
+/*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/
+{
+   typedef struct {
+        GLint v0, v1;   /* Y(v0) < Y(v1) */
+	GLfloat dx;	/* X(v1) - X(v0) */
+	GLfloat dy;	/* Y(v1) - Y(v0) */
+	GLfixed fdxdy;	/* dx/dy in fixed-point */
+	GLfixed fsx;	/* first sample point x coord */
+	GLfixed fsy;
+	GLfloat adjy;	/* adjust from v[0]->fy to fsy, scaled */
+	GLint lines;	/* number of lines to be sampled on this edge */
+	GLfixed fx0;	/* fixed pt X of lower endpoint */
+   } EdgeT;
+
+#ifdef INTERP_Z
+   const GLint depthBits = ctx->Visual.DepthBits;
+   const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0;
+   const GLfloat maxDepth = ctx->Visual.DepthMaxF;
+#define FixedToDepth(F)  ((F) >> fixedToDepthShift)
+#endif
+   const struct vertex_buffer *VB = ctx->VB;
+   EdgeT eMaj, eTop, eBot;
+   GLfloat oneOverArea;
+   int vMin, vMid, vMax;       /* vertex indexes:  Y(vMin)<=Y(vMid)<=Y(vMax) */
+   float bf = ctx->backface_sign;
+
+   /* find the order of the 3 vertices along the Y axis */
+   {
+      GLfloat y0 = VB->Win.data[v0][1];
+      GLfloat y1 = VB->Win.data[v1][1];
+      GLfloat y2 = VB->Win.data[v2][1];
+
+      if (y0<=y1) {
+	 if (y1<=y2) {
+	    vMin = v0;   vMid = v1;   vMax = v2;   /* y0<=y1<=y2 */
+	 }
+	 else if (y2<=y0) {
+	    vMin = v2;   vMid = v0;   vMax = v1;   /* y2<=y0<=y1 */
+	 }
+	 else {
+	    vMin = v0;   vMid = v2;   vMax = v1;  bf = -bf; /* y0<=y2<=y1 */
+	 }
+      }
+      else {
+	 if (y0<=y2) {
+	    vMin = v1;   vMid = v0;   vMax = v2;  bf = -bf; /* y1<=y0<=y2 */
+	 }
+	 else if (y2<=y1) {
+	    vMin = v2;   vMid = v1;   vMax = v0;  bf = -bf; /* y2<=y1<=y0 */
+	 }
+	 else {
+	    vMin = v1;   vMid = v2;   vMax = v0;   /* y1<=y2<=y0 */
+	 }
+      }
+   }
+
+   /* vertex/edge relationship */
+   eMaj.v0 = vMin;   eMaj.v1 = vMax;   /*TODO: .v1's not needed */
+   eTop.v0 = vMid;   eTop.v1 = vMax;
+   eBot.v0 = vMin;   eBot.v1 = vMid;
+
+   /* compute deltas for each edge:  vertex[v1] - vertex[v0] */
+   eMaj.dx = VB->Win.data[vMax][0] - VB->Win.data[vMin][0];
+   eMaj.dy = VB->Win.data[vMax][1] - VB->Win.data[vMin][1];
+   eTop.dx = VB->Win.data[vMax][0] - VB->Win.data[vMid][0];
+   eTop.dy = VB->Win.data[vMax][1] - VB->Win.data[vMid][1];
+   eBot.dx = VB->Win.data[vMid][0] - VB->Win.data[vMin][0];
+   eBot.dy = VB->Win.data[vMid][1] - VB->Win.data[vMin][1];
+
+   /* compute oneOverArea */
+   {
+      const GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
+
+      /* Do backface culling */
+      if (area * bf < 0.0)
+	 return;
+
+      if (area == 0.0F)
+         return;
+
+      /* check for very tiny triangle */
+      if (area * area < 0.0025F)  /* square it to ensure positive value */
+         oneOverArea = 1.0F / 0.0025F;  /* a close-enough value */
+      else
+         oneOverArea = 1.0F / area;
+   }
+
+#ifndef DO_OCCLUSION_TEST
+   ctx->OcclusionResult = GL_TRUE;
+#endif
+
+   /* Edge setup.  For a triangle strip these could be reused... */
+   {
+      /* fixed point Y coordinates */
+      GLfixed vMin_fx = FloatToFixed(VB->Win.data[vMin][0] + 0.5F);
+      GLfixed vMin_fy = FloatToFixed(VB->Win.data[vMin][1] - 0.5F);
+      GLfixed vMid_fx = FloatToFixed(VB->Win.data[vMid][0] + 0.5F);
+      GLfixed vMid_fy = FloatToFixed(VB->Win.data[vMid][1] - 0.5F);
+      GLfixed vMax_fy = FloatToFixed(VB->Win.data[vMax][1] - 0.5F);
+
+      eMaj.fsy = FixedCeil(vMin_fy);
+      eMaj.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eMaj.fsy);
+      if (eMaj.lines > 0) {
+         GLfloat dxdy = eMaj.dx / eMaj.dy;
+         eMaj.fdxdy = SignedFloatToFixed(dxdy);
+         eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy);  /* SCALED! */
+         eMaj.fx0 = vMin_fx;
+         eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * dxdy);
+      }
+      else {
+         return;  /*CULLED*/
+      }
+
+      eTop.fsy = FixedCeil(vMid_fy);
+      eTop.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eTop.fsy);
+      if (eTop.lines > 0) {
+         GLfloat dxdy = eTop.dx / eTop.dy;
+         eTop.fdxdy = SignedFloatToFixed(dxdy);
+         eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */
+         eTop.fx0 = vMid_fx;
+         eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * dxdy);
+      }
+
+      eBot.fsy = FixedCeil(vMin_fy);
+      eBot.lines = FixedToInt(vMid_fy + FIXED_ONE - FIXED_EPSILON - eBot.fsy);
+      if (eBot.lines > 0) {
+         GLfloat dxdy = eBot.dx / eBot.dy;
+         eBot.fdxdy = SignedFloatToFixed(dxdy);
+         eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy);  /* SCALED! */
+         eBot.fx0 = vMin_fx;
+         eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * dxdy);
+      }
+   }
+
+   /*
+    * Conceptually, we view a triangle as two subtriangles
+    * separated by a perfectly horizontal line.  The edge that is
+    * intersected by this line is one with maximal absolute dy; we
+    * call it a ``major'' edge.  The other two edges are the
+    * ``top'' edge (for the upper subtriangle) and the ``bottom''
+    * edge (for the lower subtriangle).  If either of these two
+    * edges is horizontal or very close to horizontal, the
+    * corresponding subtriangle might cover zero sample points;
+    * we take care to handle such cases, for performance as well
+    * as correctness.
+    *
+    * By stepping rasterization parameters along the major edge,
+    * we can avoid recomputing them at the discontinuity where
+    * the top and bottom edges meet.  However, this forces us to
+    * be able to scan both left-to-right and right-to-left. 
+    * Also, we must determine whether the major edge is at the
+    * left or right side of the triangle.  We do this by
+    * computing the magnitude of the cross-product of the major
+    * and top edges.  Since this magnitude depends on the sine of
+    * the angle between the two edges, its sign tells us whether
+    * we turn to the left or to the right when travelling along
+    * the major edge to the top edge, and from this we infer
+    * whether the major edge is on the left or the right.
+    *
+    * Serendipitously, this cross-product magnitude is also a
+    * value we need to compute the iteration parameter
+    * derivatives for the triangle, and it can be used to perform
+    * backface culling because its sign tells us whether the
+    * triangle is clockwise or counterclockwise.  In this code we
+    * refer to it as ``area'' because it's also proportional to
+    * the pixel area of the triangle.
+    */
+
+   {
+      GLint ltor;		/* true if scanning left-to-right */
+#ifdef INTERP_Z
+      GLfloat dzdx, dzdy;      GLfixed fdzdx;
+      GLfloat dfogdx, dfogdy;      GLfixed fdfogdx;
+#endif
+#ifdef INTERP_RGB
+      GLfloat drdx, drdy;      GLfixed fdrdx;
+      GLfloat dgdx, dgdy;      GLfixed fdgdx;
+      GLfloat dbdx, dbdy;      GLfixed fdbdx;
+#endif
+#ifdef INTERP_SPEC
+      GLfloat dsrdx, dsrdy;    GLfixed fdsrdx;
+      GLfloat dsgdx, dsgdy;    GLfixed fdsgdx;
+      GLfloat dsbdx, dsbdy;    GLfixed fdsbdx;
+#endif
+#ifdef INTERP_ALPHA
+      GLfloat dadx, dady;      GLfixed fdadx;
+#endif
+#ifdef INTERP_INDEX
+      GLfloat didx, didy;      GLfixed fdidx;
+#endif
+#ifdef INTERP_INT_TEX
+      GLfloat dsdx, dsdy;      GLfixed fdsdx;
+      GLfloat dtdx, dtdy;      GLfixed fdtdx;
+#endif
+#ifdef INTERP_TEX
+      GLfloat dsdx, dsdy;
+      GLfloat dtdx, dtdy;
+      GLfloat dudx, dudy;
+      GLfloat dvdx, dvdy;
+#endif
+#ifdef INTERP_MULTITEX
+      GLfloat dsdx[MAX_TEXTURE_UNITS], dsdy[MAX_TEXTURE_UNITS];
+      GLfloat dtdx[MAX_TEXTURE_UNITS], dtdy[MAX_TEXTURE_UNITS];
+      GLfloat dudx[MAX_TEXTURE_UNITS], dudy[MAX_TEXTURE_UNITS];
+      GLfloat dvdx[MAX_TEXTURE_UNITS], dvdy[MAX_TEXTURE_UNITS];
+#endif
+
+      /*
+       * Execute user-supplied setup code
+       */
+#ifdef SETUP_CODE
+      SETUP_CODE
+#endif
+
+      ltor = (oneOverArea < 0.0F);
+
+      /* compute d?/dx and d?/dy derivatives */
+#ifdef INTERP_Z
+      {
+         GLfloat eMaj_dz, eBot_dz;
+         eMaj_dz = VB->Win.data[vMax][2] - VB->Win.data[vMin][2];
+         eBot_dz = VB->Win.data[vMid][2] - VB->Win.data[vMin][2];
+         dzdx = oneOverArea * (eMaj_dz * eBot.dy - eMaj.dy * eBot_dz);
+         if (dzdx > maxDepth || dzdx < -maxDepth) {
+            /* probably a sliver triangle */
+            dzdx = 0.0;
+            dzdy = 0.0;
+         }
+         else {
+            dzdy = oneOverArea * (eMaj.dx * eBot_dz - eMaj_dz * eBot.dx);
+         }
+         if (depthBits <= 16)
+            fdzdx = SignedFloatToFixed(dzdx);
+         else
+            fdzdx = (GLint) dzdx;
+      }
+      {
+         GLfloat eMaj_dfog, eBot_dfog;
+         eMaj_dfog = (VB->FogCoordPtr->data[vMax] - VB->FogCoordPtr->data[vMin]) * 256;
+         eBot_dfog = (VB->FogCoordPtr->data[vMid] - VB->FogCoordPtr->data[vMin]) * 256;
+         dfogdx = oneOverArea * (eMaj_dfog * eBot.dy - eMaj.dy * eBot_dfog);
+         fdfogdx = SignedFloatToFixed(dfogdx);
+         dfogdy = oneOverArea * (eMaj.dx * eBot_dfog - eMaj_dfog * eBot.dx);
+      }
+#endif
+#ifdef INTERP_RGB
+      {
+         GLfloat eMaj_dr, eBot_dr;
+         eMaj_dr = (GLint) VB->ColorPtr->data[vMax][0]
+                 - (GLint) VB->ColorPtr->data[vMin][0];
+         eBot_dr = (GLint) VB->ColorPtr->data[vMid][0]
+                 - (GLint) VB->ColorPtr->data[vMin][0];
+         drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr);
+         fdrdx = SignedFloatToFixed(drdx);
+         drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx);
+      }
+      {
+         GLfloat eMaj_dg, eBot_dg;
+         eMaj_dg = (GLint) VB->ColorPtr->data[vMax][1]
+                 - (GLint) VB->ColorPtr->data[vMin][1];
+	 eBot_dg = (GLint) VB->ColorPtr->data[vMid][1]
+                 - (GLint) VB->ColorPtr->data[vMin][1];
+         dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg);
+         fdgdx = SignedFloatToFixed(dgdx);
+         dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx);
+      }
+      {
+         GLfloat eMaj_db, eBot_db;
+         eMaj_db = (GLint) VB->ColorPtr->data[vMax][2]
+                 - (GLint) VB->ColorPtr->data[vMin][2];
+         eBot_db = (GLint) VB->ColorPtr->data[vMid][2]
+                 - (GLint) VB->ColorPtr->data[vMin][2];
+         dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db);
+         fdbdx = SignedFloatToFixed(dbdx);
+	 dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx);
+      }
+#endif
+#ifdef INTERP_SPEC
+      {
+         GLfloat eMaj_dsr, eBot_dsr;
+         eMaj_dsr = (GLint) VB->SecondaryColorPtr->data[vMax][0]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][0];
+         eBot_dsr = (GLint) VB->SecondaryColorPtr->data[vMid][0]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][0];
+         dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr);
+         fdsrdx = SignedFloatToFixed(dsrdx);
+         dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx);
+      }
+      {
+         GLfloat eMaj_dsg, eBot_dsg;
+         eMaj_dsg = (GLint) VB->SecondaryColorPtr->data[vMax][1]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][1];
+	 eBot_dsg = (GLint) VB->SecondaryColorPtr->data[vMid][1]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][1];
+         dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg);
+         fdsgdx = SignedFloatToFixed(dsgdx);
+         dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx);
+      }
+      {
+         GLfloat eMaj_dsb, eBot_dsb;
+         eMaj_dsb = (GLint) VB->SecondaryColorPtr->data[vMax][2]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][2];
+         eBot_dsb = (GLint) VB->SecondaryColorPtr->data[vMid][2]
+                  - (GLint) VB->SecondaryColorPtr->data[vMin][2];
+         dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb);
+         fdsbdx = SignedFloatToFixed(dsbdx);
+	 dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx);
+      }
+#endif
+#ifdef INTERP_ALPHA
+      {
+         GLfloat eMaj_da, eBot_da;
+         eMaj_da = (GLint) VB->ColorPtr->data[vMax][3]
+                 - (GLint) VB->ColorPtr->data[vMin][3];
+         eBot_da = (GLint) VB->ColorPtr->data[vMid][3]
+                 - (GLint) VB->ColorPtr->data[vMin][3];
+         dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da);
+         fdadx = SignedFloatToFixed(dadx);
+         dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx);
+      }
+#endif
+#ifdef INTERP_INDEX
+      {
+         GLfloat eMaj_di, eBot_di;
+         eMaj_di = (GLint) VB->IndexPtr->data[vMax]
+                 - (GLint) VB->IndexPtr->data[vMin];
+         eBot_di = (GLint) VB->IndexPtr->data[vMid]
+                 - (GLint) VB->IndexPtr->data[vMin];
+         didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di);
+         fdidx = SignedFloatToFixed(didx);
+         didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx);
+      }
+#endif
+#ifdef INTERP_INT_TEX
+      {
+         GLfloat eMaj_ds, eBot_ds;
+         eMaj_ds = (VB->TexCoordPtr[0]->data[vMax][0]
+                  - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE;
+         eBot_ds = (VB->TexCoordPtr[0]->data[vMid][0]
+                  - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE;
+         dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
+         fdsdx = SignedFloatToFixed(dsdx);
+         dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
+      }
+      if (VB->TexCoordPtr[0]->size > 1) {
+         GLfloat eMaj_dt, eBot_dt;
+         eMaj_dt = (VB->TexCoordPtr[0]->data[vMax][1]
+                  - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE;
+         eBot_dt = (VB->TexCoordPtr[0]->data[vMid][1]
+                  - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE;
+         dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
+         fdtdx = SignedFloatToFixed(dtdx);
+         dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
+      }
+      else {
+         dtdx = 0;
+         fdtdx = SignedFloatToFixed(dtdx);
+         dtdy = 0;
+      }
+
+#endif
+#ifdef INTERP_TEX
+      {
+         GLfloat wMax = VB->Win.data[vMax][3];
+         GLfloat wMin = VB->Win.data[vMin][3];
+         GLfloat wMid = VB->Win.data[vMid][3];
+         GLfloat eMaj_ds, eBot_ds;
+         GLfloat eMaj_dt, eBot_dt;
+         GLfloat eMaj_du, eBot_du;
+         GLfloat eMaj_dv, eBot_dv;
+
+         eMaj_ds = VB->TexCoordPtr[0]->data[vMax][0] * wMax
+                 - VB->TexCoordPtr[0]->data[vMin][0] * wMin;
+         eBot_ds = VB->TexCoordPtr[0]->data[vMid][0] * wMid
+                 - VB->TexCoordPtr[0]->data[vMin][0] * wMin;
+         dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
+         dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
+
+
+	 if (VB->TexCoordPtr[0]->size > 1) {
+	    eMaj_dt = VB->TexCoordPtr[0]->data[vMax][1] * wMax
+                    - VB->TexCoordPtr[0]->data[vMin][1] * wMin;
+	    eBot_dt = VB->TexCoordPtr[0]->data[vMid][1] * wMid
+                    - VB->TexCoordPtr[0]->data[vMin][1] * wMin;
+	    dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
+	    dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
+	 }
+         else {
+	    dtdx = 0;
+	    dtdy = 0; 
+	 }
+
+	 if (VB->TexCoordPtr[0]->size > 2) {
+	    eMaj_du = VB->TexCoordPtr[0]->data[vMax][2] * wMax
+                    - VB->TexCoordPtr[0]->data[vMin][2] * wMin;
+	    eBot_du = VB->TexCoordPtr[0]->data[vMid][2] * wMid
+                    - VB->TexCoordPtr[0]->data[vMin][2] * wMin;
+	    dudx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du);
+	    dudy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx);
+	 }
+         else {
+	    dudx = 0;
+	    dudy = 0;
+	 }
+
+	 if (VB->TexCoordPtr[0]->size > 3) {
+	    eMaj_dv = VB->TexCoordPtr[0]->data[vMax][3] * wMax
+                    - VB->TexCoordPtr[0]->data[vMin][3] * wMin;
+	    eBot_dv = VB->TexCoordPtr[0]->data[vMid][3] * wMid
+                    - VB->TexCoordPtr[0]->data[vMin][3] * wMin;
+	    dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
+	    dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
+	 }
+         else {
+	    eMaj_dv = wMax - wMin;
+	    eBot_dv = wMid - wMin;
+	    dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
+	    dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
+	 }
+      }
+#endif
+#ifdef INTERP_MULTITEX
+      {
+         GLfloat wMax = VB->Win.data[vMax][3];
+         GLfloat wMin = VB->Win.data[vMin][3];
+         GLfloat wMid = VB->Win.data[vMid][3];
+         GLuint u;
+         for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+            if (ctx->Texture.Unit[u].ReallyEnabled) {
+               GLfloat eMaj_ds, eBot_ds;
+               GLfloat eMaj_dt, eBot_dt;
+               GLfloat eMaj_du, eBot_du;
+               GLfloat eMaj_dv, eBot_dv;
+               eMaj_ds = VB->TexCoordPtr[u]->data[vMax][0] * wMax
+                       - VB->TexCoordPtr[u]->data[vMin][0] * wMin;
+               eBot_ds = VB->TexCoordPtr[u]->data[vMid][0] * wMid
+                       - VB->TexCoordPtr[u]->data[vMin][0] * wMin;
+               dsdx[u] = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
+               dsdy[u] = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
+
+               if (VB->TexCoordPtr[u]->size > 1) {
+                  eMaj_dt = VB->TexCoordPtr[u]->data[vMax][1] * wMax
+                          - VB->TexCoordPtr[u]->data[vMin][1] * wMin;
+                  eBot_dt = VB->TexCoordPtr[u]->data[vMid][1] * wMid
+                          - VB->TexCoordPtr[u]->data[vMin][1] * wMin;
+                  dtdx[u] = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
+                  dtdy[u] = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
+               }
+               else {
+                  dtdx[u] = 0.0;
+                  dtdy[u] = 0.0;
+               }
+
+               if (VB->TexCoordPtr[u]->size > 2) {
+                  eMaj_du = VB->TexCoordPtr[u]->data[vMax][2] * wMax
+                          - VB->TexCoordPtr[u]->data[vMin][2] * wMin;
+                  eBot_du = VB->TexCoordPtr[u]->data[vMid][2] * wMid
+                          - VB->TexCoordPtr[u]->data[vMin][2] * wMin;
+                  dudx[u] = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du);
+                  dudy[u] = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx);
+               }
+               else {
+                  dudx[u] = 0.0;
+                  dudy[u] = 0.0;
+               }
+
+               if (VB->TexCoordPtr[u]->size > 3) {
+                  eMaj_dv = VB->TexCoordPtr[u]->data[vMax][3] * wMax
+                          - VB->TexCoordPtr[u]->data[vMin][3] * wMin;
+                  eBot_dv = VB->TexCoordPtr[u]->data[vMid][3] * wMid
+                          - VB->TexCoordPtr[u]->data[vMin][3] * wMin;
+                  dvdx[u] = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
+                  dvdy[u] = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
+               }
+               else {
+                  eMaj_dv = wMax - wMin;
+                  eBot_dv = wMid - wMin;
+                  dvdx[u] = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
+                  dvdy[u] = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
+               }
+            }
+         }
+      }
+#endif
+
+      /*
+       * We always sample at pixel centers.  However, we avoid
+       * explicit half-pixel offsets in this code by incorporating
+       * the proper offset in each of x and y during the
+       * transformation to window coordinates.
+       *
+       * We also apply the usual rasterization rules to prevent
+       * cracks and overlaps.  A pixel is considered inside a
+       * subtriangle if it meets all of four conditions: it is on or
+       * to the right of the left edge, strictly to the left of the
+       * right edge, on or below the top edge, and strictly above
+       * the bottom edge.  (Some edges may be degenerate.)
+       *
+       * The following discussion assumes left-to-right scanning
+       * (that is, the major edge is on the left); the right-to-left
+       * case is a straightforward variation.
+       *
+       * We start by finding the half-integral y coordinate that is
+       * at or below the top of the triangle.  This gives us the
+       * first scan line that could possibly contain pixels that are
+       * inside the triangle.
+       *
+       * Next we creep down the major edge until we reach that y,
+       * and compute the corresponding x coordinate on the edge. 
+       * Then we find the half-integral x that lies on or just
+       * inside the edge.  This is the first pixel that might lie in
+       * the interior of the triangle.  (We won't know for sure
+       * until we check the other edges.)
+       *
+       * As we rasterize the triangle, we'll step down the major
+       * edge.  For each step in y, we'll move an integer number
+       * of steps in x.  There are two possible x step sizes, which
+       * we'll call the ``inner'' step (guaranteed to land on the
+       * edge or inside it) and the ``outer'' step (guaranteed to
+       * land on the edge or outside it).  The inner and outer steps
+       * differ by one.  During rasterization we maintain an error
+       * term that indicates our distance from the true edge, and
+       * select either the inner step or the outer step, whichever
+       * gets us to the first pixel that falls inside the triangle.
+       *
+       * All parameters (z, red, etc.) as well as the buffer
+       * addresses for color and z have inner and outer step values,
+       * so that we can increment them appropriately.  This method
+       * eliminates the need to adjust parameters by creeping a
+       * sub-pixel amount into the triangle at each scanline.
+       */
+
+      {
+         int subTriangle;
+         GLfixed fx, fxLeftEdge, fxRightEdge, fdxLeftEdge, fdxRightEdge;
+         GLfixed fdxOuter;
+         int idxOuter;
+         float dxOuter;
+         GLfixed fError, fdError;
+         float adjx, adjy;
+         GLfixed fy;
+         int iy;
+#ifdef PIXEL_ADDRESS
+         PIXEL_TYPE *pRow;
+         int dPRowOuter, dPRowInner;  /* offset in bytes */
+#endif
+#ifdef INTERP_Z
+#  ifdef DEPTH_TYPE
+         DEPTH_TYPE *zRow;
+         int dZRowOuter, dZRowInner;  /* offset in bytes */
+#  endif
+         GLfixed fz, fdzOuter, fdzInner;
+         GLfixed ffog, fdfogOuter, fdfogInner;
+#endif
+#ifdef INTERP_RGB
+         GLfixed fr, fdrOuter, fdrInner;
+         GLfixed fg, fdgOuter, fdgInner;
+         GLfixed fb, fdbOuter, fdbInner;
+#endif
+#ifdef INTERP_SPEC
+         GLfixed fsr, fdsrOuter, fdsrInner;
+         GLfixed fsg, fdsgOuter, fdsgInner;
+         GLfixed fsb, fdsbOuter, fdsbInner;
+#endif
+#ifdef INTERP_ALPHA
+         GLfixed fa, fdaOuter, fdaInner;
+#endif
+#ifdef INTERP_INDEX
+         GLfixed fi, fdiOuter, fdiInner;
+#endif
+#ifdef INTERP_INT_TEX
+         GLfixed fs, fdsOuter, fdsInner;
+         GLfixed ft, fdtOuter, fdtInner;
+#endif
+#ifdef INTERP_TEX
+         GLfloat sLeft, dsOuter, dsInner;
+         GLfloat tLeft, dtOuter, dtInner;
+         GLfloat uLeft, duOuter, duInner;
+         GLfloat vLeft, dvOuter, dvInner;
+#endif
+#ifdef INTERP_MULTITEX
+         GLfloat sLeft[MAX_TEXTURE_UNITS];
+         GLfloat tLeft[MAX_TEXTURE_UNITS];
+         GLfloat uLeft[MAX_TEXTURE_UNITS];
+         GLfloat vLeft[MAX_TEXTURE_UNITS];
+         GLfloat dsOuter[MAX_TEXTURE_UNITS], dsInner[MAX_TEXTURE_UNITS];
+         GLfloat dtOuter[MAX_TEXTURE_UNITS], dtInner[MAX_TEXTURE_UNITS];
+         GLfloat duOuter[MAX_TEXTURE_UNITS], duInner[MAX_TEXTURE_UNITS];
+         GLfloat dvOuter[MAX_TEXTURE_UNITS], dvInner[MAX_TEXTURE_UNITS];
+#endif
+
+         for (subTriangle=0; subTriangle<=1; subTriangle++) {
+            EdgeT *eLeft, *eRight;
+            int setupLeft, setupRight;
+            int lines;
+
+            if (subTriangle==0) {
+               /* bottom half */
+               if (ltor) {
+                  eLeft = &eMaj;
+                  eRight = &eBot;
+                  lines = eRight->lines;
+                  setupLeft = 1;
+                  setupRight = 1;
+               }
+               else {
+                  eLeft = &eBot;
+                  eRight = &eMaj;
+                  lines = eLeft->lines;
+                  setupLeft = 1;
+                  setupRight = 1;
+               }
+            }
+            else {
+               /* top half */
+               if (ltor) {
+                  eLeft = &eMaj;
+                  eRight = &eTop;
+                  lines = eRight->lines;
+                  setupLeft = 0;
+                  setupRight = 1;
+               }
+               else {
+                  eLeft = &eTop;
+                  eRight = &eMaj;
+                  lines = eLeft->lines;
+                  setupLeft = 1;
+                  setupRight = 0;
+               }
+               if (lines == 0)
+                  return;
+            }
+
+            if (setupLeft && eLeft->lines > 0) {
+               GLint vLower;
+               GLfixed fsx = eLeft->fsx;
+               fx = FixedCeil(fsx);
+               fError = fx - fsx - FIXED_ONE;
+               fxLeftEdge = fsx - FIXED_EPSILON;
+               fdxLeftEdge = eLeft->fdxdy;
+               fdxOuter = FixedFloor(fdxLeftEdge - FIXED_EPSILON);
+               fdError = fdxOuter - fdxLeftEdge + FIXED_ONE;
+               idxOuter = FixedToInt(fdxOuter);
+               dxOuter = (float) idxOuter;
+               (void) dxOuter;
+
+               fy = eLeft->fsy;
+               iy = FixedToInt(fy);
+
+               adjx = (float)(fx - eLeft->fx0);  /* SCALED! */
+               adjy = eLeft->adjy;		 /* SCALED! */
+               (void) adjx;  /* silence compiler warnings */
+               (void) adjy;  /* silence compiler warnings */
+
+               vLower = eLeft->v0;
+               (void) vLower;  /* silence compiler warnings */
+
+#ifdef PIXEL_ADDRESS
+               {
+                  pRow = PIXEL_ADDRESS( FixedToInt(fxLeftEdge), iy );
+                  dPRowOuter = -((int)BYTES_PER_ROW) + idxOuter * sizeof(PIXEL_TYPE);
+                  /* negative because Y=0 at bottom and increases upward */
+               }
+#endif
+               /*
+                * Now we need the set of parameter (z, color, etc.) values at
+                * the point (fx, fy).  This gives us properly-sampled parameter
+                * values that we can step from pixel to pixel.  Furthermore,
+                * although we might have intermediate results that overflow
+                * the normal parameter range when we step temporarily outside
+                * the triangle, we shouldn't overflow or underflow for any
+                * pixel that's actually inside the triangle.
+                */
+
+#ifdef INTERP_Z
+               {
+                  GLfloat z0 = VB->Win.data[vLower][2] + ctx->PolygonZoffset;
+                  if (depthBits <= 16) {
+                     /* interpolate fixed-pt values */
+                     GLfloat tmp = (z0 * FIXED_SCALE +
+                                    dzdx * adjx + dzdy * adjy) + FIXED_HALF;
+                     if (tmp < MAX_GLUINT / 2)
+                        fz = (GLfixed) tmp;
+                     else
+                        fz = MAX_GLUINT / 2;
+                     fdzOuter = SignedFloatToFixed(dzdy + dxOuter * dzdx);
+                  }
+                  else {
+                     /* interpolate depth values exactly */
+                     fz = (GLint) (z0 + dzdx*FixedToFloat(adjx) + dzdy*FixedToFloat(adjy));
+                     fdzOuter = (GLint) (dzdy + dxOuter * dzdx);
+                  }
+#  ifdef DEPTH_TYPE
+                  zRow = (DEPTH_TYPE *) _mesa_zbuffer_address(ctx, FixedToInt(fxLeftEdge), iy);
+                  dZRowOuter = (ctx->DrawBuffer->Width + idxOuter) * sizeof(DEPTH_TYPE);
+#  endif
+               }
+               ffog = FloatToFixed(VB->FogCoordPtr->data[vLower]) * 256 + dfogdx * adjx + dfogdy * adjy + FIXED_HALF;
+               fdfogOuter = SignedFloatToFixed(dfogdy + dxOuter * dfogdx);
+#endif
+#ifdef INTERP_RGB
+               fr = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][0])
+                              + drdx * adjx + drdy * adjy) + FIXED_HALF;
+               fdrOuter = SignedFloatToFixed(drdy + dxOuter * drdx);
+
+               fg = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][1])
+                              + dgdx * adjx + dgdy * adjy) + FIXED_HALF;
+               fdgOuter = SignedFloatToFixed(dgdy + dxOuter * dgdx);
+
+               fb = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][2])
+                              + dbdx * adjx + dbdy * adjy) + FIXED_HALF;
+               fdbOuter = SignedFloatToFixed(dbdy + dxOuter * dbdx);
+#endif
+#ifdef INTERP_SPEC
+               fsr = (GLfixed)(IntToFixed(VB->SecondaryColorPtr->data[vLower][0])
+                               + dsrdx * adjx + dsrdy * adjy) + FIXED_HALF;
+               fdsrOuter = SignedFloatToFixed(dsrdy + dxOuter * dsrdx);
+
+               fsg = (GLfixed)(IntToFixed(VB->SecondaryColorPtr->data[vLower][1])
+                               + dsgdx * adjx + dsgdy * adjy) + FIXED_HALF;
+               fdsgOuter = SignedFloatToFixed(dsgdy + dxOuter * dsgdx);
+
+               fsb = (GLfixed)(IntToFixed(VB->SecondaryColorPtr->data[vLower][2])
+                               + dsbdx * adjx + dsbdy * adjy) + FIXED_HALF;
+               fdsbOuter = SignedFloatToFixed(dsbdy + dxOuter * dsbdx);
+#endif
+#ifdef INTERP_ALPHA
+               fa = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][3])
+                              + dadx * adjx + dady * adjy) + FIXED_HALF;
+               fdaOuter = SignedFloatToFixed(dady + dxOuter * dadx);
+#endif
+#ifdef INTERP_INDEX
+               fi = (GLfixed)(VB->IndexPtr->data[vLower] * FIXED_SCALE
+                              + didx * adjx + didy * adjy) + FIXED_HALF;
+               fdiOuter = SignedFloatToFixed(didy + dxOuter * didx);
+#endif
+#ifdef INTERP_INT_TEX
+               {
+                  GLfloat s0, t0;
+                  s0 = VB->TexCoordPtr[0]->data[vLower][0] * S_SCALE;
+                  fs = (GLfixed)(s0 * FIXED_SCALE + dsdx * adjx + dsdy * adjy) + FIXED_HALF;
+                  fdsOuter = SignedFloatToFixed(dsdy + dxOuter * dsdx);
+
+		  if (VB->TexCoordPtr[0]->size > 1)
+		  {
+		     t0 = VB->TexCoordPtr[0]->data[vLower][1] * T_SCALE;
+		     ft = (GLfixed)(t0 * FIXED_SCALE + dtdx * adjx + dtdy * adjy) + FIXED_HALF;
+		     fdtOuter = SignedFloatToFixed(dtdy + dxOuter * dtdx);
+		  } 
+		  else
+		  {
+		     t0 = 0;
+		     ft = (GLfixed) FIXED_HALF;
+		     fdtOuter = SignedFloatToFixed(0);
+		  }
+	       }
+#endif
+#ifdef INTERP_TEX
+               {
+                  GLfloat invW = VB->Win.data[vLower][3];
+                  GLfloat s0, t0, u0, v0;
+                  s0 = VB->TexCoordPtr[0]->data[vLower][0] * invW;
+                  sLeft = s0 + (dsdx * adjx + dsdy * adjy) * (1.0F/FIXED_SCALE);
+                  dsOuter = dsdy + dxOuter * dsdx;
+		  if (VB->TexCoordPtr[0]->size > 1) {		  
+		     t0 = VB->TexCoordPtr[0]->data[vLower][1] * invW;
+		     tLeft = t0 + (dtdx * adjx + dtdy * adjy) * (1.0F/FIXED_SCALE);
+		     dtOuter = dtdy + dxOuter * dtdx;
+		  }
+                  else {
+		     tLeft = dtOuter = 0.0;
+		  }
+		  if (VB->TexCoordPtr[0]->size > 2) {		  
+		     u0 = VB->TexCoordPtr[0]->data[vLower][2] * invW;
+		     uLeft = u0 + (dudx * adjx + dudy * adjy) * (1.0F/FIXED_SCALE);
+		     duOuter = dudy + dxOuter * dudx;
+		  }
+                  else {
+		     uLeft = duOuter = 0.0;
+		  }
+		  if (VB->TexCoordPtr[0]->size > 3) {		  
+		     v0 = VB->TexCoordPtr[0]->data[vLower][3] * invW;
+		  }
+                  else {
+		     v0 = invW;
+		  }
+		  vLeft = v0 + (dvdx * adjx + dvdy * adjy) * (1.0F/FIXED_SCALE);
+		  dvOuter = dvdy + dxOuter * dvdx;
+               }
+#endif
+#ifdef INTERP_MULTITEX
+               {
+                  GLuint u;
+                  for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+                     if (ctx->Texture.Unit[u].ReallyEnabled) {
+                        GLfloat invW = VB->Win.data[vLower][3];
+                        GLfloat s0, t0, u0, v0;
+                        s0 = VB->TexCoordPtr[u]->data[vLower][0] * invW;
+                        sLeft[u] = s0 + (dsdx[u] * adjx + dsdy[u] * adjy) * (1.0F/FIXED_SCALE);
+                        dsOuter[u] = dsdy[u] + dxOuter * dsdx[u];
+                        if (VB->TexCoordPtr[u]->size > 1) {
+                           t0 = VB->TexCoordPtr[u]->data[vLower][1] * invW;
+                           tLeft[u] = t0 + (dtdx[u] * adjx + dtdy[u] * adjy) * (1.0F/FIXED_SCALE);
+                           dtOuter[u] = dtdy[u] + dxOuter * dtdx[u];
+                        }
+                        else {
+                           tLeft[u] = dtOuter[u] = 0.0;
+                        }
+                        if (VB->TexCoordPtr[u]->size > 2) {
+                           u0 = VB->TexCoordPtr[u]->data[vLower][2] * invW;
+                           uLeft[u] = u0 + (dudx[u] * adjx + dudy[u] * adjy) * (1.0F/FIXED_SCALE);
+                           duOuter[u] = dudy[u] + dxOuter * dudx[u];
+                        }
+                        else {
+                           uLeft[u] = duOuter[u] = 0.0;
+                        }
+                        if (VB->TexCoordPtr[u]->size > 3) {
+                           v0 = VB->TexCoordPtr[u]->data[vLower][3] * invW;
+                        }
+                        else {
+                           v0 =  invW;
+                        }
+                        vLeft[u] = v0 + (dvdx[u] * adjx + dvdy[u] * adjy) * (1.0F/FIXED_SCALE);
+                        dvOuter[u] = dvdy[u] + dxOuter * dvdx[u];
+                     }
+                  }
+               }
+#endif
+
+            } /*if setupLeft*/
+
+
+            if (setupRight && eRight->lines>0) {
+               fxRightEdge = eRight->fsx - FIXED_EPSILON;
+               fdxRightEdge = eRight->fdxdy;
+            }
+
+            if (lines==0) {
+               continue;
+            }
+
+
+            /* Rasterize setup */
+#ifdef PIXEL_ADDRESS
+            dPRowInner = dPRowOuter + sizeof(PIXEL_TYPE);
+#endif
+#ifdef INTERP_Z
+#  ifdef DEPTH_TYPE
+            dZRowInner = dZRowOuter + sizeof(DEPTH_TYPE);
+#  endif
+            fdzInner = fdzOuter + fdzdx;
+            fdfogInner = fdfogOuter + fdfogdx;
+#endif
+#ifdef INTERP_RGB
+            fdrInner = fdrOuter + fdrdx;
+            fdgInner = fdgOuter + fdgdx;
+            fdbInner = fdbOuter + fdbdx;
+#endif
+#ifdef INTERP_SPEC
+            fdsrInner = fdsrOuter + fdsrdx;
+            fdsgInner = fdsgOuter + fdsgdx;
+            fdsbInner = fdsbOuter + fdsbdx;
+#endif
+#ifdef INTERP_ALPHA
+            fdaInner = fdaOuter + fdadx;
+#endif
+#ifdef INTERP_INDEX
+            fdiInner = fdiOuter + fdidx;
+#endif
+#ifdef INTERP_INT_TEX
+            fdsInner = fdsOuter + fdsdx;
+            fdtInner = fdtOuter + fdtdx;
+#endif
+#ifdef INTERP_TEX
+	    dsInner = dsOuter + dsdx;
+	    dtInner = dtOuter + dtdx;
+	    duInner = duOuter + dudx;
+	    dvInner = dvOuter + dvdx;
+#endif
+#ifdef INTERP_MULTITEX
+            {
+               GLuint u;
+               for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+                  if (ctx->Texture.Unit[u].ReallyEnabled) {
+                     dsInner[u] = dsOuter[u] + dsdx[u];
+                     dtInner[u] = dtOuter[u] + dtdx[u];
+                     duInner[u] = duOuter[u] + dudx[u];
+                     dvInner[u] = dvOuter[u] + dvdx[u];
+                  }
+               }
+            }
+#endif
+
+            while (lines>0) {
+               /* initialize the span interpolants to the leftmost value */
+               /* ff = fixed-pt fragment */
+               GLint left = FixedToInt(fxLeftEdge);
+               GLint right = FixedToInt(fxRightEdge);
+#ifdef INTERP_Z
+               GLfixed ffz = fz;
+               GLfixed fffog = ffog;
+#endif
+#ifdef INTERP_RGB
+               GLfixed ffr = fr,  ffg = fg,  ffb = fb;
+#endif
+#ifdef INTERP_SPEC
+               GLfixed ffsr = fsr,  ffsg = fsg,  ffsb = fsb;
+#endif
+#ifdef INTERP_ALPHA
+               GLfixed ffa = fa;
+#endif
+#ifdef INTERP_INDEX
+               GLfixed ffi = fi;
+#endif
+#ifdef INTERP_INT_TEX
+               GLfixed ffs = fs,  fft = ft;
+#endif
+#ifdef INTERP_TEX
+               GLfloat ss = sLeft, tt = tLeft, uu = uLeft, vv = vLeft;
+#endif
+#ifdef INTERP_MULTITEX
+               GLfloat ss[MAX_TEXTURE_UNITS];
+               GLfloat tt[MAX_TEXTURE_UNITS];
+               GLfloat uu[MAX_TEXTURE_UNITS];
+               GLfloat vv[MAX_TEXTURE_UNITS];
+               {
+                  GLuint u;
+                  for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+                     if (ctx->Texture.Unit[u].ReallyEnabled) {
+                        ss[u] = sLeft[u];
+                        tt[u] = tLeft[u];
+                        uu[u] = uLeft[u];
+                        vv[u] = vLeft[u];
+                     }
+                  }
+               }
+#endif
+
+#ifdef INTERP_RGB
+               {
+                  /* need this to accomodate round-off errors */
+                  GLfixed ffrend = ffr+(right-left-1)*fdrdx;
+                  GLfixed ffgend = ffg+(right-left-1)*fdgdx;
+                  GLfixed ffbend = ffb+(right-left-1)*fdbdx;
+                  if (ffrend<0) ffr -= ffrend;
+                  if (ffgend<0) ffg -= ffgend;
+                  if (ffbend<0) ffb -= ffbend;
+                  if (ffr<0) ffr = 0;
+                  if (ffg<0) ffg = 0;
+                  if (ffb<0) ffb = 0;
+               }
+#endif
+#ifdef INTERP_SPEC
+               {
+                  /* need this to accomodate round-off errors */
+                  GLfixed ffsrend = ffsr+(right-left-1)*fdsrdx;
+                  GLfixed ffsgend = ffsg+(right-left-1)*fdsgdx;
+                  GLfixed ffsbend = ffsb+(right-left-1)*fdsbdx;
+                  if (ffsrend<0) ffsr -= ffsrend;
+                  if (ffsgend<0) ffsg -= ffsgend;
+                  if (ffsbend<0) ffsb -= ffsbend;
+                  if (ffsr<0) ffsr = 0;
+                  if (ffsg<0) ffsg = 0;
+                  if (ffsb<0) ffsb = 0;
+               }
+#endif
+#ifdef INTERP_ALPHA
+               {
+                  GLfixed ffaend = ffa+(right-left-1)*fdadx;
+                  if (ffaend<0) ffa -= ffaend;
+                  if (ffa<0) ffa = 0;
+               }
+#endif
+#ifdef INTERP_INDEX
+               if (ffi<0) ffi = 0;
+#endif
+
+               INNER_LOOP( left, right, iy );
+
+               /*
+                * Advance to the next scan line.  Compute the
+                * new edge coordinates, and adjust the
+                * pixel-center x coordinate so that it stays
+                * on or inside the major edge.
+                */
+               iy++;
+               lines--;
+
+               fxLeftEdge += fdxLeftEdge;
+               fxRightEdge += fdxRightEdge;
+
+
+               fError += fdError;
+               if (fError >= 0) {
+                  fError -= FIXED_ONE;
+#ifdef PIXEL_ADDRESS
+                  pRow = (PIXEL_TYPE *) ((GLubyte*)pRow + dPRowOuter);
+#endif
+#ifdef INTERP_Z
+#  ifdef DEPTH_TYPE
+                  zRow = (DEPTH_TYPE *) ((GLubyte*)zRow + dZRowOuter);
+#  endif
+                  fz += fdzOuter;
+                  ffog += fdfogOuter;
+#endif
+#ifdef INTERP_RGB
+                  fr += fdrOuter;   fg += fdgOuter;   fb += fdbOuter;
+#endif
+#ifdef INTERP_SPEC
+                  fsr += fdsrOuter;   fsg += fdsgOuter;   fsb += fdsbOuter;
+#endif
+#ifdef INTERP_ALPHA
+                  fa += fdaOuter;
+#endif
+#ifdef INTERP_INDEX
+                  fi += fdiOuter;
+#endif
+#ifdef INTERP_INT_TEX
+                  fs += fdsOuter;   ft += fdtOuter;
+#endif
+#ifdef INTERP_TEX
+		  sLeft += dsOuter;
+		  tLeft += dtOuter;
+		  uLeft += duOuter;
+		  vLeft += dvOuter;
+#endif
+#ifdef INTERP_MULTITEX
+                  {
+                     GLuint u;
+                     for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+                        if (ctx->Texture.Unit[u].ReallyEnabled) {
+                           sLeft[u] += dsOuter[u];
+                           tLeft[u] += dtOuter[u];
+                           uLeft[u] += duOuter[u];
+                           vLeft[u] += dvOuter[u];
+                        }
+                     }
+                  }
+#endif
+               }
+               else {
+#ifdef PIXEL_ADDRESS
+                  pRow = (PIXEL_TYPE *) ((GLubyte*)pRow + dPRowInner);
+#endif
+#ifdef INTERP_Z
+#  ifdef DEPTH_TYPE
+                  zRow = (DEPTH_TYPE *) ((GLubyte*)zRow + dZRowInner);
+#  endif
+                  fz += fdzInner;
+                  ffog += fdfogInner;
+#endif
+#ifdef INTERP_RGB
+                  fr += fdrInner;   fg += fdgInner;   fb += fdbInner;
+#endif
+#ifdef INTERP_SPEC
+                  fsr += fdsrInner;   fsg += fdsgInner;   fsb += fdsbInner;
+#endif
+#ifdef INTERP_ALPHA
+                  fa += fdaInner;
+#endif
+#ifdef INTERP_INDEX
+                  fi += fdiInner;
+#endif
+#ifdef INTERP_INT_TEX
+                  fs += fdsInner;   ft += fdtInner;
+#endif
+#ifdef INTERP_TEX
+		  sLeft += dsInner;
+		  tLeft += dtInner;
+		  uLeft += duInner;
+		  vLeft += dvInner;
+#endif
+#ifdef INTERP_MULTITEX
+                  {
+                     GLuint u;
+                     for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
+                        if (ctx->Texture.Unit[u].ReallyEnabled) {
+                           sLeft[u] += dsInner[u];
+                           tLeft[u] += dtInner[u];
+                           uLeft[u] += duInner[u];
+                           vLeft[u] += dvInner[u];
+                        }
+                     }
+                  }
+#endif
+               }
+            } /*while lines>0*/
+
+         } /* for subTriangle */
+
+      }
+   }
+}
+
+#undef SETUP_CODE
+#undef INNER_LOOP
+
+#undef PIXEL_TYPE
+#undef BYTES_PER_ROW
+#undef PIXEL_ADDRESS
+
+#undef INTERP_Z
+#undef INTERP_RGB
+#undef INTERP_SPEC
+#undef INTERP_ALPHA
+#undef INTERP_INDEX
+#undef INTERP_INT_TEX
+#undef INTERP_TEX
+#undef INTERP_MULTITEX
+
+#undef S_SCALE
+#undef T_SCALE
+
+#undef FixedToDepth
+
+#undef DO_OCCLUSION_TEST