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haiku/src/kits/opengl/mesa/swrast/s_tritemp.h

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Add a first draft OpenGL kit. The OpenGL software renderer add-on should follow soon. Allow to link GLTeapot as native, but without renderer, nothing is displayed ;-) git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13283 a95241bf-73f2-0310-859d-f6bbb57e9c96
2005-06-27 00:21:09 +04:00
/*
* Mesa 3-D graphics library
* Version: 6.1
*
* Copyright (C) 1999-2004 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 vertex Z values
* INTERP_W - if defined, interpolate vertex W values
* INTERP_FOG - if defined, interpolate fog values
* INTERP_RGB - if defined, interpolate RGB values
* INTERP_ALPHA - if defined, interpolate Alpha values (req's INTERP_RGB)
* INTERP_SPEC - if defined, interpolate specular RGB 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
* CLEANUP_CODE - code to execute at end of triangle
*
* The following macro MUST be defined:
* RENDER_SPAN(span) - code to write a span of pixels.
*
* 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!
*
*
* Some notes on rasterization accuracy:
*
* This code uses fixed point arithmetic (the GLfixed type) to iterate
* over the triangle edges and interpolate ancillary data (such as Z,
* color, secondary color, etc). The number of fractional bits in
* GLfixed and the value of SUB_PIXEL_BITS has a direct bearing on the
* accuracy of rasterization.
*
* If SUB_PIXEL_BITS=4 then we'll snap the vertices to the nearest
* 1/16 of a pixel. If we're walking up a long, nearly vertical edge
* (dx=1/16, dy=1024) we'll need 4 + 10 = 14 fractional bits in
* GLfixed to walk the edge without error. If the maximum viewport
* height is 4K pixels, then we'll need 4 + 12 = 16 fractional bits.
*
* Historically, Mesa has used 11 fractional bits in GLfixed, snaps
* vertices to 1/16 pixel and allowed a maximum viewport height of 2K
* pixels. 11 fractional bits is actually insufficient for accurately
* rasterizing some triangles. More recently, the maximum viewport
* height was increased to 4K pixels. Thus, Mesa should be using 16
* fractional bits in GLfixed. Unfortunately, there may be some issues
* with setting FIXED_FRAC_BITS=16, such as multiplication overflow.
* This will have to be examined in some detail...
*
* For now, if you find rasterization errors, particularly with tall,
* sliver triangles, try increasing FIXED_FRAC_BITS and/or decreasing
* SUB_PIXEL_BITS.
*/
/*
* ColorTemp is used for intermediate color values.
*/
#if CHAN_TYPE == GL_FLOAT
#define ColorTemp GLfloat
#else
#define ColorTemp GLint /* same as GLfixed */
#endif
/*
* Walk triangle edges with GLfixed or GLdouble
*/
#if TRIANGLE_WALK_DOUBLE
#define GLinterp GLdouble
#define InterpToInt(X) ((GLint) (X))
#define INTERP_ONE 1.0
#else
#define GLinterp GLfixed
#define InterpToInt(X) FixedToInt(X)
#define INTERP_ONE FIXED_ONE
#endif
/*
* Either loop over all texture units, or just use unit zero.
*/
#ifdef INTERP_MULTITEX
#define TEX_UNIT_LOOP(CODE) \
{ \
GLuint u; \
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { \
if (ctx->Texture._EnabledCoordUnits & (1 << u)) { \
CODE \
} \
} \
}
#define INTERP_TEX
#elif defined(INTERP_TEX)
#define TEX_UNIT_LOOP(CODE) \
{ \
const GLuint u = 0; \
CODE \
}
#endif
static void NAME(GLcontext *ctx, const SWvertex *v0,
const SWvertex *v1,
const SWvertex *v2 )
{
typedef struct {
const SWvertex *v0, *v1; /* Y(v0) < Y(v1) */
#if TRIANGLE_WALK_DOUBLE
GLdouble dx; /* X(v1) - X(v0) */
GLdouble dy; /* Y(v1) - Y(v0) */
GLdouble dxdy; /* dx/dy */
GLdouble adjy; /* adjust from v[0]->fy to fsy, scaled */
GLdouble fsx; /* first sample point x coord */
GLdouble fsy;
GLdouble fx0; /*X of lower endpoint */
#else
GLfloat dx; /* X(v1) - X(v0) */
GLfloat dy; /* Y(v1) - Y(v0) */
GLfloat dxdy; /* dx/dy */
GLfixed fdxdy; /* dx/dy in fixed-point */
GLfloat adjy; /* adjust from v[0]->fy to fsy, scaled */
GLfixed fsx; /* first sample point x coord */
GLfixed fsy;
GLfixed fx0; /* fixed pt X of lower endpoint */
#endif
GLint lines; /* number of lines to be sampled on this edge */
} EdgeT;
#ifdef INTERP_Z
const GLint depthBits = ctx->Visual.depthBits;
const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0;
const GLfloat maxDepth = ctx->DepthMaxF;
#define FixedToDepth(F) ((F) >> fixedToDepthShift)
#endif
EdgeT eMaj, eTop, eBot;
GLfloat oneOverArea;
const SWvertex *vMin, *vMid, *vMax; /* Y(vMin)<=Y(vMid)<=Y(vMax) */
GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceSign;
#if !TRIANGLE_WALK_DOUBLE
const GLint snapMask = ~((FIXED_ONE / (1 << SUB_PIXEL_BITS)) - 1); /* for x/y coord snapping */
#endif
GLinterp vMin_fx, vMin_fy, vMid_fx, vMid_fy, vMax_fx, vMax_fy;
struct sw_span span;
INIT_SPAN(span, GL_POLYGON, 0, 0, 0);
#ifdef INTERP_Z
(void) fixedToDepthShift;
#endif
/*
printf("%s()\n", __FUNCTION__);
printf(" %g, %g, %g\n", v0->win[0], v0->win[1], v0->win[2]);
printf(" %g, %g, %g\n", v1->win[0], v1->win[1], v1->win[2]);
printf(" %g, %g, %g\n", v2->win[0], v2->win[1], v2->win[2]);
*/
/*
ASSERT(v0->win[2] >= 0.0);
ASSERT(v1->win[2] >= 0.0);
ASSERT(v2->win[2] >= 0.0);
*/
/* Compute fixed point x,y coords w/ half-pixel offsets and snapping.
* And find the order of the 3 vertices along the Y axis.
*/
{
#if TRIANGLE_WALK_DOUBLE
const GLdouble fy0 = v0->win[1] - 0.5;
const GLdouble fy1 = v1->win[1] - 0.5;
const GLdouble fy2 = v2->win[1] - 0.5;
#else
const GLfixed fy0 = FloatToFixed(v0->win[1] - 0.5F) & snapMask;
const GLfixed fy1 = FloatToFixed(v1->win[1] - 0.5F) & snapMask;
const GLfixed fy2 = FloatToFixed(v2->win[1] - 0.5F) & snapMask;
#endif
if (fy0 <= fy1) {
if (fy1 <= fy2) {
/* y0 <= y1 <= y2 */
vMin = v0; vMid = v1; vMax = v2;
vMin_fy = fy0; vMid_fy = fy1; vMax_fy = fy2;
}
else if (fy2 <= fy0) {
/* y2 <= y0 <= y1 */
vMin = v2; vMid = v0; vMax = v1;
vMin_fy = fy2; vMid_fy = fy0; vMax_fy = fy1;
}
else {
/* y0 <= y2 <= y1 */
vMin = v0; vMid = v2; vMax = v1;
vMin_fy = fy0; vMid_fy = fy2; vMax_fy = fy1;
bf = -bf;
}
}
else {
if (fy0 <= fy2) {
/* y1 <= y0 <= y2 */
vMin = v1; vMid = v0; vMax = v2;
vMin_fy = fy1; vMid_fy = fy0; vMax_fy = fy2;
bf = -bf;
}
else if (fy2 <= fy1) {
/* y2 <= y1 <= y0 */
vMin = v2; vMid = v1; vMax = v0;
vMin_fy = fy2; vMid_fy = fy1; vMax_fy = fy0;
bf = -bf;
}
else {
/* y1 <= y2 <= y0 */
vMin = v1; vMid = v2; vMax = v0;
vMin_fy = fy1; vMid_fy = fy2; vMax_fy = fy0;
}
}
/* fixed point X coords */
#if TRIANGLE_WALK_DOUBLE
vMin_fx = vMin->win[0] + 0.5;
vMid_fx = vMid->win[0] + 0.5;
vMax_fx = vMax->win[0] + 0.5;
#else
vMin_fx = FloatToFixed(vMin->win[0] + 0.5F) & snapMask;
vMid_fx = FloatToFixed(vMid->win[0] + 0.5F) & snapMask;
vMax_fx = FloatToFixed(vMax->win[0] + 0.5F) & snapMask;
#endif
}
/* 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[upper] - vertex[lower] */
#if TRIANGLE_WALK_DOUBLE
eMaj.dx = vMax_fx - vMin_fx;
eMaj.dy = vMax_fy - vMin_fy;
eTop.dx = vMax_fx - vMid_fx;
eTop.dy = vMax_fy - vMid_fy;
eBot.dx = vMid_fx - vMin_fx;
eBot.dy = vMid_fy - vMin_fy;
#else
eMaj.dx = FixedToFloat(vMax_fx - vMin_fx);
eMaj.dy = FixedToFloat(vMax_fy - vMin_fy);
eTop.dx = FixedToFloat(vMax_fx - vMid_fx);
eTop.dy = FixedToFloat(vMax_fy - vMid_fy);
eBot.dx = FixedToFloat(vMid_fx - vMin_fx);
eBot.dy = FixedToFloat(vMid_fy - vMin_fy);
#endif
/* compute area, oneOverArea and perform backface culling */
{
#if TRIANGLE_WALK_DOUBLE
const GLdouble area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
#else
const GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
#endif
/* Do backface culling */
if (area * bf < 0.0)
return;
if (IS_INF_OR_NAN(area) || area == 0.0F)
return;
oneOverArea = 1.0F / area;
}
span.facing = ctx->_Facing; /* for 2-sided stencil test */
/* Edge setup. For a triangle strip these could be reused... */
{
#if TRIANGLE_WALK_DOUBLE
eMaj.fsy = CEILF(vMin_fy);
eMaj.lines = (GLint) CEILF(vMax_fy - eMaj.fsy);
#else
eMaj.fsy = FixedCeil(vMin_fy);
eMaj.lines = FixedToInt(FixedCeil(vMax_fy - eMaj.fsy));
#endif
if (eMaj.lines > 0) {
eMaj.dxdy = eMaj.dx / eMaj.dy;
#if TRIANGLE_WALK_DOUBLE
eMaj.adjy = (eMaj.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */
eMaj.fx0 = vMin_fx;
eMaj.fsx = eMaj.fx0 + (eMaj.adjy * eMaj.dxdy) / (GLdouble) FIXED_SCALE;
#else
eMaj.fdxdy = SignedFloatToFixed(eMaj.dxdy);
eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy); /* SCALED! */
eMaj.fx0 = vMin_fx;
eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * eMaj.dxdy);
#endif
}
else {
return; /*CULLED*/
}
#if TRIANGLE_WALK_DOUBLE
eTop.fsy = CEILF(vMid_fy);
eTop.lines = (GLint) CEILF(vMax_fy - eTop.fsy);
#else
eTop.fsy = FixedCeil(vMid_fy);
eTop.lines = FixedToInt(FixedCeil(vMax_fy - eTop.fsy));
#endif
if (eTop.lines > 0) {
eTop.dxdy = eTop.dx / eTop.dy;
#if TRIANGLE_WALK_DOUBLE
eTop.adjy = (eTop.fsy - vMid_fy) * FIXED_SCALE; /* SCALED! */
eTop.fx0 = vMid_fx;
eTop.fsx = eTop.fx0 + (eTop.adjy * eTop.dxdy) / (GLdouble) FIXED_SCALE;
#else
eTop.fdxdy = SignedFloatToFixed(eTop.dxdy);
eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */
eTop.fx0 = vMid_fx;
eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * eTop.dxdy);
#endif
}
#if TRIANGLE_WALK_DOUBLE
eBot.fsy = CEILF(vMin_fy);
eBot.lines = (GLint) CEILF(vMid_fy - eBot.fsy);
#else
eBot.fsy = FixedCeil(vMin_fy);
eBot.lines = FixedToInt(FixedCeil(vMid_fy - eBot.fsy));
#endif
if (eBot.lines > 0) {
eBot.dxdy = eBot.dx / eBot.dy;
#if TRIANGLE_WALK_DOUBLE
eBot.adjy = (eBot.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */
eBot.fx0 = vMin_fx;
eBot.fsx = eBot.fx0 + (eBot.adjy * eBot.dxdy) / (GLdouble) FIXED_SCALE;
#else
eBot.fdxdy = SignedFloatToFixed(eBot.dxdy);
eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy); /* SCALED! */
eBot.fx0 = vMin_fx;
eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * eBot.dxdy);
#endif
}
}
/*
* 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 scan_from_left_to_right; /* true if scanning left-to-right */
#ifdef INTERP_INDEX
GLfloat didx, didy;
#endif
/*
* Execute user-supplied setup code
*/
#ifdef SETUP_CODE
SETUP_CODE
#endif
scan_from_left_to_right = (oneOverArea < 0.0F);
/* compute d?/dx and d?/dy derivatives */
#ifdef INTERP_Z
span.interpMask |= SPAN_Z;
{
GLfloat eMaj_dz = vMax->win[2] - vMin->win[2];
GLfloat eBot_dz = vMid->win[2] - vMin->win[2];
span.dzdx = oneOverArea * (eMaj_dz * eBot.dy - eMaj.dy * eBot_dz);
if (span.dzdx > maxDepth || span.dzdx < -maxDepth) {
/* probably a sliver triangle */
span.dzdx = 0.0;
span.dzdy = 0.0;
}
else {
span.dzdy = oneOverArea * (eMaj.dx * eBot_dz - eMaj_dz * eBot.dx);
}
if (depthBits <= 16)
span.zStep = SignedFloatToFixed(span.dzdx);
else
span.zStep = (GLint) span.dzdx;
}
#endif
#ifdef INTERP_W
span.interpMask |= SPAN_W;
{
const GLfloat eMaj_dw = vMax->win[3] - vMin->win[3];
const GLfloat eBot_dw = vMid->win[3] - vMin->win[3];
span.dwdx = oneOverArea * (eMaj_dw * eBot.dy - eMaj.dy * eBot_dw);
span.dwdy = oneOverArea * (eMaj.dx * eBot_dw - eMaj_dw * eBot.dx);
}
#endif
#ifdef INTERP_FOG
span.interpMask |= SPAN_FOG;
{
# ifdef INTERP_W
const GLfloat wMax = vMax->win[3], wMin = vMin->win[3], wMid = vMid->win[3];
const GLfloat eMaj_dfog = vMax->fog * wMax - vMin->fog * wMin;
const GLfloat eBot_dfog = vMid->fog * wMid - vMin->fog * wMin;
# else
const GLfloat eMaj_dfog = vMax->fog - vMin->fog;
const GLfloat eBot_dfog = vMid->fog - vMin->fog;
# endif
span.dfogdx = oneOverArea * (eMaj_dfog * eBot.dy - eMaj.dy * eBot_dfog);
span.dfogdy = oneOverArea * (eMaj.dx * eBot_dfog - eMaj_dfog * eBot.dx);
span.fogStep = span.dfogdx;
}
#endif
#ifdef INTERP_RGB
span.interpMask |= SPAN_RGBA;
if (ctx->Light.ShadeModel == GL_SMOOTH) {
GLfloat eMaj_dr = (GLfloat) ((ColorTemp) vMax->color[RCOMP] - (ColorTemp) vMin->color[RCOMP]);
GLfloat eBot_dr = (GLfloat) ((ColorTemp) vMid->color[RCOMP] - (ColorTemp) vMin->color[RCOMP]);
GLfloat eMaj_dg = (GLfloat) ((ColorTemp) vMax->color[GCOMP] - (ColorTemp) vMin->color[GCOMP]);
GLfloat eBot_dg = (GLfloat) ((ColorTemp) vMid->color[GCOMP] - (ColorTemp) vMin->color[GCOMP]);
GLfloat eMaj_db = (GLfloat) ((ColorTemp) vMax->color[BCOMP] - (ColorTemp) vMin->color[BCOMP]);
GLfloat eBot_db = (GLfloat) ((ColorTemp) vMid->color[BCOMP] - (ColorTemp) vMin->color[BCOMP]);
# ifdef INTERP_ALPHA
GLfloat eMaj_da = (GLfloat) ((ColorTemp) vMax->color[ACOMP] - (ColorTemp) vMin->color[ACOMP]);
GLfloat eBot_da = (GLfloat) ((ColorTemp) vMid->color[ACOMP] - (ColorTemp) vMin->color[ACOMP]);
# endif
span.drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr);
span.drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx);
span.dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg);
span.dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx);
span.dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db);
span.dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx);
# if CHAN_TYPE == GL_FLOAT
span.redStep = span.drdx;
span.greenStep = span.dgdx;
span.blueStep = span.dbdx;
# else
span.redStep = SignedFloatToFixed(span.drdx);
span.greenStep = SignedFloatToFixed(span.dgdx);
span.blueStep = SignedFloatToFixed(span.dbdx);
# endif /* GL_FLOAT */
# ifdef INTERP_ALPHA
span.dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da);
span.dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx);
# if CHAN_TYPE == GL_FLOAT
span.alphaStep = span.dadx;
# else
span.alphaStep = SignedFloatToFixed(span.dadx);
# endif /* GL_FLOAT */
# endif /* INTERP_ALPHA */
}
else {
ASSERT (ctx->Light.ShadeModel == GL_FLAT);
span.interpMask |= SPAN_FLAT;
span.drdx = span.drdy = 0.0F;
span.dgdx = span.dgdy = 0.0F;
span.dbdx = span.dbdy = 0.0F;
# if CHAN_TYPE == GL_FLOAT
span.redStep = 0.0F;
span.greenStep = 0.0F;
span.blueStep = 0.0F;
# else
span.redStep = 0;
span.greenStep = 0;
span.blueStep = 0;
# endif /* GL_FLOAT */
# ifdef INTERP_ALPHA
span.dadx = span.dady = 0.0F;
# if CHAN_TYPE == GL_FLOAT
span.alphaStep = 0.0F;
# else
span.alphaStep = 0;
# endif /* GL_FLOAT */
# endif
}
#endif /* INTERP_RGB */
#ifdef INTERP_SPEC
span.interpMask |= SPAN_SPEC;
if (ctx->Light.ShadeModel == GL_SMOOTH) {
GLfloat eMaj_dsr = (GLfloat) ((ColorTemp) vMax->specular[RCOMP] - (ColorTemp) vMin->specular[RCOMP]);
GLfloat eBot_dsr = (GLfloat) ((ColorTemp) vMid->specular[RCOMP] - (ColorTemp) vMin->specular[RCOMP]);
GLfloat eMaj_dsg = (GLfloat) ((ColorTemp) vMax->specular[GCOMP] - (ColorTemp) vMin->specular[GCOMP]);
GLfloat eBot_dsg = (GLfloat) ((ColorTemp) vMid->specular[GCOMP] - (ColorTemp) vMin->specular[GCOMP]);
GLfloat eMaj_dsb = (GLfloat) ((ColorTemp) vMax->specular[BCOMP] - (ColorTemp) vMin->specular[BCOMP]);
GLfloat eBot_dsb = (GLfloat) ((ColorTemp) vMid->specular[BCOMP] - (ColorTemp) vMin->specular[BCOMP]);
span.dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr);
span.dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx);
span.dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg);
span.dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx);
span.dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb);
span.dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx);
# if CHAN_TYPE == GL_FLOAT
span.specRedStep = span.dsrdx;
span.specGreenStep = span.dsgdx;
span.specBlueStep = span.dsbdx;
# else
span.specRedStep = SignedFloatToFixed(span.dsrdx);
span.specGreenStep = SignedFloatToFixed(span.dsgdx);
span.specBlueStep = SignedFloatToFixed(span.dsbdx);
# endif
}
else {
span.dsrdx = span.dsrdy = 0.0F;
span.dsgdx = span.dsgdy = 0.0F;
span.dsbdx = span.dsbdy = 0.0F;
# if CHAN_TYPE == GL_FLOAT
span.specRedStep = 0.0F;
span.specGreenStep = 0.0F;
span.specBlueStep = 0.0F;
# else
span.specRedStep = 0;
span.specGreenStep = 0;
span.specBlueStep = 0;
# endif
}
#endif /* INTERP_SPEC */
#ifdef INTERP_INDEX
span.interpMask |= SPAN_INDEX;
if (ctx->Light.ShadeModel == GL_SMOOTH) {
GLfloat eMaj_di = vMax->index - vMin->index;
GLfloat eBot_di = vMid->index - vMin->index;
didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di);
didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx);
span.indexStep = SignedFloatToFixed(didx);
}
else {
span.interpMask |= SPAN_FLAT;
didx = didy = 0.0F;
span.indexStep = 0;
}
#endif
#ifdef INTERP_INT_TEX
span.interpMask |= SPAN_INT_TEXTURE;
{
GLfloat eMaj_ds = (vMax->texcoord[0][0] - vMin->texcoord[0][0]) * S_SCALE;
GLfloat eBot_ds = (vMid->texcoord[0][0] - vMin->texcoord[0][0]) * S_SCALE;
GLfloat eMaj_dt = (vMax->texcoord[0][1] - vMin->texcoord[0][1]) * T_SCALE;
GLfloat eBot_dt = (vMid->texcoord[0][1] - vMin->texcoord[0][1]) * T_SCALE;
span.texStepX[0][0] = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
span.texStepY[0][0] = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
span.texStepX[0][1] = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
span.texStepY[0][1] = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
span.intTexStep[0] = SignedFloatToFixed(span.texStepX[0][0]);
span.intTexStep[1] = SignedFloatToFixed(span.texStepX[0][1]);
}
#endif
#ifdef INTERP_TEX
span.interpMask |= SPAN_TEXTURE;
{
/* win[3] is 1/W */
const GLfloat wMax = vMax->win[3], wMin = vMin->win[3], wMid = vMid->win[3];
TEX_UNIT_LOOP(
GLfloat eMaj_ds = vMax->texcoord[u][0] * wMax - vMin->texcoord[u][0] * wMin;
GLfloat eBot_ds = vMid->texcoord[u][0] * wMid - vMin->texcoord[u][0] * wMin;
GLfloat eMaj_dt = vMax->texcoord[u][1] * wMax - vMin->texcoord[u][1] * wMin;
GLfloat eBot_dt = vMid->texcoord[u][1] * wMid - vMin->texcoord[u][1] * wMin;
GLfloat eMaj_du = vMax->texcoord[u][2] * wMax - vMin->texcoord[u][2] * wMin;
GLfloat eBot_du = vMid->texcoord[u][2] * wMid - vMin->texcoord[u][2] * wMin;
GLfloat eMaj_dv = vMax->texcoord[u][3] * wMax - vMin->texcoord[u][3] * wMin;
GLfloat eBot_dv = vMid->texcoord[u][3] * wMid - vMin->texcoord[u][3] * wMin;
span.texStepX[u][0] = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
span.texStepY[u][0] = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
span.texStepX[u][1] = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
span.texStepY[u][1] = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
span.texStepX[u][2] = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du);
span.texStepY[u][2] = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx);
span.texStepX[u][3] = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
span.texStepY[u][3] = 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.
*/
{
GLint subTriangle;
GLinterp fxLeftEdge = 0, fxRightEdge = 0;
GLinterp fdxLeftEdge = 0, fdxRightEdge = 0;
GLinterp fError = 0, fdError = 0;
#ifdef PIXEL_ADDRESS
PIXEL_TYPE *pRow = NULL;
GLint dPRowOuter = 0, dPRowInner; /* offset in bytes */
#endif
#ifdef INTERP_Z
# ifdef DEPTH_TYPE
DEPTH_TYPE *zRow = NULL;
GLint dZRowOuter = 0, dZRowInner; /* offset in bytes */
# endif
GLfixed zLeft = 0, fdzOuter = 0, fdzInner;
#endif
#ifdef INTERP_W
GLfloat wLeft = 0, dwOuter = 0, dwInner;
#endif
#ifdef INTERP_FOG
GLfloat fogLeft = 0, dfogOuter = 0, dfogInner;
#endif
#ifdef INTERP_RGB
ColorTemp rLeft = 0, fdrOuter = 0, fdrInner;
ColorTemp gLeft = 0, fdgOuter = 0, fdgInner;
ColorTemp bLeft = 0, fdbOuter = 0, fdbInner;
#endif
#ifdef INTERP_ALPHA
ColorTemp aLeft = 0, fdaOuter = 0, fdaInner;
#endif
#ifdef INTERP_SPEC
ColorTemp srLeft=0, dsrOuter=0, dsrInner;
ColorTemp sgLeft=0, dsgOuter=0, dsgInner;
ColorTemp sbLeft=0, dsbOuter=0, dsbInner;
#endif
#ifdef INTERP_INDEX
GLfixed iLeft=0, diOuter=0, diInner;
#endif
#ifdef INTERP_INT_TEX
GLfixed sLeft=0, dsOuter=0, dsInner;
GLfixed tLeft=0, dtOuter=0, dtInner;
#endif
#ifdef INTERP_TEX
GLfloat sLeft[MAX_TEXTURE_COORD_UNITS];
GLfloat tLeft[MAX_TEXTURE_COORD_UNITS];
GLfloat uLeft[MAX_TEXTURE_COORD_UNITS];
GLfloat vLeft[MAX_TEXTURE_COORD_UNITS];
GLfloat dsOuter[MAX_TEXTURE_COORD_UNITS], dsInner[MAX_TEXTURE_COORD_UNITS];
GLfloat dtOuter[MAX_TEXTURE_COORD_UNITS], dtInner[MAX_TEXTURE_COORD_UNITS];
GLfloat duOuter[MAX_TEXTURE_COORD_UNITS], duInner[MAX_TEXTURE_COORD_UNITS];
GLfloat dvOuter[MAX_TEXTURE_COORD_UNITS], dvInner[MAX_TEXTURE_COORD_UNITS];
#endif
for (subTriangle=0; subTriangle<=1; subTriangle++) {
EdgeT *eLeft, *eRight;
int setupLeft, setupRight;
int lines;
if (subTriangle==0) {
/* bottom half */
if (scan_from_left_to_right) {
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 (scan_from_left_to_right) {
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) {
const SWvertex *vLower = eLeft->v0;
#if TRIANGLE_WALK_DOUBLE
const GLdouble fsy = eLeft->fsy;
const GLdouble fsx = eLeft->fsx;
const GLdouble fx = CEILF(fsx);
const GLdouble adjx = (fx - eLeft->fx0) * FIXED_SCALE; /* SCALED! */
#else
const GLfixed fsy = eLeft->fsy;
const GLfixed fsx = eLeft->fsx; /* no fractional part */
const GLfixed fx = FixedCeil(fsx); /* no fractional part */
const GLfixed adjx = (GLinterp) (fx - eLeft->fx0); /* SCALED! */
#endif
const GLinterp adjy = (GLinterp) eLeft->adjy; /* SCALED! */
GLint idxOuter;
#if TRIANGLE_WALK_DOUBLE
GLdouble dxOuter;
fError = fx - fsx - 1.0;
fxLeftEdge = fsx;
fdxLeftEdge = eLeft->dxdy;
dxOuter = FLOORF(fdxLeftEdge);
fdError = dxOuter - fdxLeftEdge + 1.0;
idxOuter = (GLint) dxOuter;
span.y = (GLint) fsy;
#else
GLfloat dxOuter;
GLfixed fdxOuter;
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 = (GLfloat) idxOuter;
span.y = FixedToInt(fsy);
#endif
/* silence warnings on some compilers */
(void) dxOuter;
(void) adjx;
(void) adjy;
(void) vLower;
#ifdef PIXEL_ADDRESS
{
pRow = (PIXEL_TYPE *) PIXEL_ADDRESS(InterpToInt(fxLeftEdge), span.y);
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, fsy). 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 = vLower->win[2];
if (depthBits <= 16) {
/* interpolate fixed-pt values */
GLfloat tmp = (z0 * FIXED_SCALE + span.dzdx * adjx + span.dzdy * adjy) + FIXED_HALF;
if (tmp < MAX_GLUINT / 2)
zLeft = (GLfixed) tmp;
else
zLeft = MAX_GLUINT / 2;
fdzOuter = SignedFloatToFixed(span.dzdy + dxOuter * span.dzdx);
}
else {
/* interpolate depth values exactly */
zLeft = (GLint) (z0 + span.dzdx * FixedToFloat(adjx) + span.dzdy * FixedToFloat(adjy));
fdzOuter = (GLint) (span.dzdy + dxOuter * span.dzdx);
}
# ifdef DEPTH_TYPE
zRow = (DEPTH_TYPE *)
_swrast_zbuffer_address(ctx, InterpToInt(fxLeftEdge), span.y);
dZRowOuter = (ctx->DrawBuffer->Width + idxOuter) * sizeof(DEPTH_TYPE);
# endif
}
#endif
#ifdef INTERP_W
wLeft = vLower->win[3] + (span.dwdx * adjx + span.dwdy * adjy) * (1.0F/FIXED_SCALE);
dwOuter = span.dwdy + dxOuter * span.dwdx;
#endif
#ifdef INTERP_FOG
# ifdef INTERP_W
fogLeft = vLower->fog * vLower->win[3] + (span.dfogdx * adjx + span.dfogdy * adjy) * (1.0F/FIXED_SCALE);
# else
fogLeft = vLower->fog + (span.dfogdx * adjx + span.dfogdy * adjy) * (1.0F/FIXED_SCALE);
# endif
dfogOuter = span.dfogdy + dxOuter * span.dfogdx;
#endif
#ifdef INTERP_RGB
if (ctx->Light.ShadeModel == GL_SMOOTH) {
# if CHAN_TYPE == GL_FLOAT
rLeft = vLower->color[RCOMP] + (span.drdx * adjx + span.drdy * adjy) * (1.0F / FIXED_SCALE);
gLeft = vLower->color[GCOMP] + (span.dgdx * adjx + span.dgdy * adjy) * (1.0F / FIXED_SCALE);
bLeft = vLower->color[BCOMP] + (span.dbdx * adjx + span.dbdy * adjy) * (1.0F / FIXED_SCALE);
fdrOuter = span.drdy + dxOuter * span.drdx;
fdgOuter = span.dgdy + dxOuter * span.dgdx;
fdbOuter = span.dbdy + dxOuter * span.dbdx;
# else
rLeft = (GLint)(ChanToFixed(vLower->color[RCOMP]) + span.drdx * adjx + span.drdy * adjy) + FIXED_HALF;
gLeft = (GLint)(ChanToFixed(vLower->color[GCOMP]) + span.dgdx * adjx + span.dgdy * adjy) + FIXED_HALF;
bLeft = (GLint)(ChanToFixed(vLower->color[BCOMP]) + span.dbdx * adjx + span.dbdy * adjy) + FIXED_HALF;
fdrOuter = SignedFloatToFixed(span.drdy + dxOuter * span.drdx);
fdgOuter = SignedFloatToFixed(span.dgdy + dxOuter * span.dgdx);
fdbOuter = SignedFloatToFixed(span.dbdy + dxOuter * span.dbdx);
# endif
# ifdef INTERP_ALPHA
# if CHAN_TYPE == GL_FLOAT
aLeft = vLower->color[ACOMP] + (span.dadx * adjx + span.dady * adjy) * (1.0F / FIXED_SCALE);
fdaOuter = span.dady + dxOuter * span.dadx;
# else
aLeft = (GLint)(ChanToFixed(vLower->color[ACOMP]) + span.dadx * adjx + span.dady * adjy) + FIXED_HALF;
fdaOuter = SignedFloatToFixed(span.dady + dxOuter * span.dadx);
# endif
# endif
}
else {
ASSERT (ctx->Light.ShadeModel == GL_FLAT);
# if CHAN_TYPE == GL_FLOAT
rLeft = v2->color[RCOMP];
gLeft = v2->color[GCOMP];
bLeft = v2->color[BCOMP];
fdrOuter = fdgOuter = fdbOuter = 0.0F;
# else
rLeft = ChanToFixed(v2->color[RCOMP]);
gLeft = ChanToFixed(v2->color[GCOMP]);
bLeft = ChanToFixed(v2->color[BCOMP]);
fdrOuter = fdgOuter = fdbOuter = 0;
# endif
# ifdef INTERP_ALPHA
# if CHAN_TYPE == GL_FLOAT
aLeft = v2->color[ACOMP];
fdaOuter = 0.0F;
# else
aLeft = ChanToFixed(v2->color[ACOMP]);
fdaOuter = 0;
# endif
# endif
}
#endif
#ifdef INTERP_SPEC
if (ctx->Light.ShadeModel == GL_SMOOTH) {
# if CHAN_TYPE == GL_FLOAT
srLeft = vLower->specular[RCOMP] + (span.dsrdx * adjx + span.dsrdy * adjy) * (1.0F / FIXED_SCALE);
sgLeft = vLower->specular[GCOMP] + (span.dsgdx * adjx + span.dsgdy * adjy) * (1.0F / FIXED_SCALE);
sbLeft = vLower->specular[BCOMP] + (span.dsbdx * adjx + span.dsbdy * adjy) * (1.0F / FIXED_SCALE);
dsrOuter = span.dsrdy + dxOuter * span.dsrdx;
dsgOuter = span.dsgdy + dxOuter * span.dsgdx;
dsbOuter = span.dsbdy + dxOuter * span.dsbdx;
# else
srLeft = (GLfixed) (ChanToFixed(vLower->specular[RCOMP]) + span.dsrdx * adjx + span.dsrdy * adjy) + FIXED_HALF;
sgLeft = (GLfixed) (ChanToFixed(vLower->specular[GCOMP]) + span.dsgdx * adjx + span.dsgdy * adjy) + FIXED_HALF;
sbLeft = (GLfixed) (ChanToFixed(vLower->specular[BCOMP]) + span.dsbdx * adjx + span.dsbdy * adjy) + FIXED_HALF;
dsrOuter = SignedFloatToFixed(span.dsrdy + dxOuter * span.dsrdx);
dsgOuter = SignedFloatToFixed(span.dsgdy + dxOuter * span.dsgdx);
dsbOuter = SignedFloatToFixed(span.dsbdy + dxOuter * span.dsbdx);
# endif
}
else {
#if CHAN_TYPE == GL_FLOAT
srLeft = v2->specular[RCOMP];
sgLeft = v2->specular[GCOMP];
sbLeft = v2->specular[BCOMP];
dsrOuter = dsgOuter = dsbOuter = 0.0F;
# else
srLeft = ChanToFixed(v2->specular[RCOMP]);
sgLeft = ChanToFixed(v2->specular[GCOMP]);
sbLeft = ChanToFixed(v2->specular[BCOMP]);
dsrOuter = dsgOuter = dsbOuter = 0;
# endif
}
#endif
#ifdef INTERP_INDEX
if (ctx->Light.ShadeModel == GL_SMOOTH) {
iLeft = (GLfixed)(vLower->index * FIXED_SCALE
+ didx * adjx + didy * adjy) + FIXED_HALF;
diOuter = SignedFloatToFixed(didy + dxOuter * didx);
}
else {
iLeft = FloatToFixed(v2->index);
diOuter = 0;
}
#endif
#ifdef INTERP_INT_TEX
{
GLfloat s0, t0;
s0 = vLower->texcoord[0][0] * S_SCALE;
sLeft = (GLfixed)(s0 * FIXED_SCALE + span.texStepX[0][0] * adjx
+ span.texStepY[0][0] * adjy) + FIXED_HALF;
dsOuter = SignedFloatToFixed(span.texStepY[0][0] + dxOuter * span.texStepX[0][0]);
t0 = vLower->texcoord[0][1] * T_SCALE;
tLeft = (GLfixed)(t0 * FIXED_SCALE + span.texStepX[0][1] * adjx
+ span.texStepY[0][1] * adjy) + FIXED_HALF;
dtOuter = SignedFloatToFixed(span.texStepY[0][1] + dxOuter * span.texStepX[0][1]);
}
#endif
#ifdef INTERP_TEX
TEX_UNIT_LOOP(
const GLfloat invW = vLower->win[3];
const GLfloat s0 = vLower->texcoord[u][0] * invW;
const GLfloat t0 = vLower->texcoord[u][1] * invW;
const GLfloat u0 = vLower->texcoord[u][2] * invW;
const GLfloat v0 = vLower->texcoord[u][3] * invW;
sLeft[u] = s0 + (span.texStepX[u][0] * adjx + span.texStepY[u][0] * adjy) * (1.0F/FIXED_SCALE);
tLeft[u] = t0 + (span.texStepX[u][1] * adjx + span.texStepY[u][1] * adjy) * (1.0F/FIXED_SCALE);
uLeft[u] = u0 + (span.texStepX[u][2] * adjx + span.texStepY[u][2] * adjy) * (1.0F/FIXED_SCALE);
vLeft[u] = v0 + (span.texStepX[u][3] * adjx + span.texStepY[u][3] * adjy) * (1.0F/FIXED_SCALE);
dsOuter[u] = span.texStepY[u][0] + dxOuter * span.texStepX[u][0];
dtOuter[u] = span.texStepY[u][1] + dxOuter * span.texStepX[u][1];
duOuter[u] = span.texStepY[u][2] + dxOuter * span.texStepX[u][2];
dvOuter[u] = span.texStepY[u][3] + dxOuter * span.texStepX[u][3];
)
#endif
} /*if setupLeft*/
if (setupRight && eRight->lines>0) {
#if TRIANGLE_WALK_DOUBLE
fxRightEdge = eRight->fsx;
fdxRightEdge = eRight->dxdy;
#else
fxRightEdge = eRight->fsx - FIXED_EPSILON;
fdxRightEdge = eRight->fdxdy;
#endif
}
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 + span.zStep;
#endif
#ifdef INTERP_W
dwInner = dwOuter + span.dwdx;
#endif
#ifdef INTERP_FOG
dfogInner = dfogOuter + span.dfogdx;
#endif
#ifdef INTERP_RGB
fdrInner = fdrOuter + span.redStep;
fdgInner = fdgOuter + span.greenStep;
fdbInner = fdbOuter + span.blueStep;
#endif
#ifdef INTERP_ALPHA
fdaInner = fdaOuter + span.alphaStep;
#endif
#ifdef INTERP_SPEC
dsrInner = dsrOuter + span.specRedStep;
dsgInner = dsgOuter + span.specGreenStep;
dsbInner = dsbOuter + span.specBlueStep;
#endif
#ifdef INTERP_INDEX
diInner = diOuter + span.indexStep;
#endif
#ifdef INTERP_INT_TEX
dsInner = dsOuter + span.intTexStep[0];
dtInner = dtOuter + span.intTexStep[1];
#endif
#ifdef INTERP_TEX
TEX_UNIT_LOOP(
dsInner[u] = dsOuter[u] + span.texStepX[u][0];
dtInner[u] = dtOuter[u] + span.texStepX[u][1];
duInner[u] = duOuter[u] + span.texStepX[u][2];
dvInner[u] = dvOuter[u] + span.texStepX[u][3];
)
#endif
while (lines > 0) {
/* initialize the span interpolants to the leftmost value */
/* ff = fixed-pt fragment */
const GLint right = InterpToInt(fxRightEdge);
span.x = InterpToInt(fxLeftEdge);
if (right <= span.x)
span.end = 0;
else
span.end = right - span.x;
#ifdef INTERP_Z
span.z = zLeft;
#endif
#ifdef INTERP_W
span.w = wLeft;
#endif
#ifdef INTERP_FOG
span.fog = fogLeft;
#endif
#ifdef INTERP_RGB
span.red = rLeft;
span.green = gLeft;
span.blue = bLeft;
#endif
#ifdef INTERP_ALPHA
span.alpha = aLeft;
#endif
#ifdef INTERP_SPEC
span.specRed = srLeft;
span.specGreen = sgLeft;
span.specBlue = sbLeft;
#endif
#ifdef INTERP_INDEX
span.index = iLeft;
#endif
#ifdef INTERP_INT_TEX
span.intTex[0] = sLeft;
span.intTex[1] = tLeft;
#endif
#ifdef INTERP_TEX
TEX_UNIT_LOOP(
span.tex[u][0] = sLeft[u];
span.tex[u][1] = tLeft[u];
span.tex[u][2] = uLeft[u];
span.tex[u][3] = vLeft[u];
)
#endif
if (span.end > 1) {
/* Under rare circumstances, we might have to fudge the
* colors. XXX does this really happen anymore???
*/
const GLint len = span.end - 1;
(void) len;
#ifdef INTERP_RGB
{
GLfixed ffrend = span.red + len * span.redStep;
GLfixed ffgend = span.green + len * span.greenStep;
GLfixed ffbend = span.blue + len * span.blueStep;
if (ffrend < 0) {
span.red -= ffrend;
if (span.red < 0)
span.red = 0;
}
if (ffgend < 0) {
span.green -= ffgend;
if (span.green < 0)
span.green = 0;
}
if (ffbend < 0) {
span.blue -= ffbend;
if (span.blue < 0)
span.blue = 0;
}
}
#endif
#ifdef INTERP_ALPHA
{
GLfixed ffaend = span.alpha + len * span.alphaStep;
if (ffaend < 0) {
span.alpha -= ffaend;
if (span.alpha < 0)
span.alpha = 0;
}
}
#endif
#ifdef INTERP_SPEC
{
GLfixed ffsrend = span.specRed + len * span.specRedStep;
GLfixed ffsgend = span.specGreen + len * span.specGreenStep;
GLfixed ffsbend = span.specBlue + len * span.specBlueStep;
if (ffsrend < 0) {
span.specRed -= ffsrend;
if (span.specRed < 0)
span.specRed = 0;
}
if (ffsgend < 0) {
span.specGreen -= ffsgend;
if (span.specGreen < 0)
span.specGreen = 0;
}
if (ffsbend < 0) {
span.specBlue -= ffsbend;
if (span.specBlue < 0)
span.specBlue = 0;
}
}
#endif
#ifdef INTERP_INDEX
if (span.index < 0)
span.index = 0;
#endif
} /* span.end > 1 */
/* This is where we actually generate fragments */
if (span.end > 0) {
RENDER_SPAN( span );
}
/*
* 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.
*/
span.y++;
lines--;
fxLeftEdge += fdxLeftEdge;
fxRightEdge += fdxRightEdge;
fError += fdError;
if (fError >= 0) {
fError -= INTERP_ONE;
#ifdef PIXEL_ADDRESS
pRow = (PIXEL_TYPE *) ((GLubyte *) pRow + dPRowOuter);
#endif
#ifdef INTERP_Z
# ifdef DEPTH_TYPE
zRow = (DEPTH_TYPE *) ((GLubyte *) zRow + dZRowOuter);
# endif
zLeft += fdzOuter;
#endif
#ifdef INTERP_W
wLeft += dwOuter;
#endif
#ifdef INTERP_FOG
fogLeft += dfogOuter;
#endif
#ifdef INTERP_RGB
rLeft += fdrOuter;
gLeft += fdgOuter;
bLeft += fdbOuter;
#endif
#ifdef INTERP_ALPHA
aLeft += fdaOuter;
#endif
#ifdef INTERP_SPEC
srLeft += dsrOuter;
sgLeft += dsgOuter;
sbLeft += dsbOuter;
#endif
#ifdef INTERP_INDEX
iLeft += diOuter;
#endif
#ifdef INTERP_INT_TEX
sLeft += dsOuter;
tLeft += dtOuter;
#endif
#ifdef INTERP_TEX
TEX_UNIT_LOOP(
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
zLeft += fdzInner;
#endif
#ifdef INTERP_W
wLeft += dwInner;
#endif
#ifdef INTERP_FOG
fogLeft += dfogInner;
#endif
#ifdef INTERP_RGB
rLeft += fdrInner;
gLeft += fdgInner;
bLeft += fdbInner;
#endif
#ifdef INTERP_ALPHA
aLeft += fdaInner;
#endif
#ifdef INTERP_SPEC
srLeft += dsrInner;
sgLeft += dsgInner;
sbLeft += dsbInner;
#endif
#ifdef INTERP_INDEX
iLeft += diInner;
#endif
#ifdef INTERP_INT_TEX
sLeft += dsInner;
tLeft += dtInner;
#endif
#ifdef INTERP_TEX
TEX_UNIT_LOOP(
sLeft[u] += dsInner[u];
tLeft[u] += dtInner[u];
uLeft[u] += duInner[u];
vLeft[u] += dvInner[u];
)
#endif
}
} /*while lines>0*/
} /* for subTriangle */
}
#ifdef CLEANUP_CODE
CLEANUP_CODE
#endif
}
}
#undef SETUP_CODE
#undef CLEANUP_CODE
#undef RENDER_SPAN
#undef PIXEL_TYPE
#undef BYTES_PER_ROW
#undef PIXEL_ADDRESS
#undef INTERP_Z
#undef INTERP_W
#undef INTERP_FOG
#undef INTERP_RGB
#undef INTERP_ALPHA
#undef INTERP_SPEC
#undef INTERP_INDEX
#undef INTERP_INT_TEX
#undef INTERP_TEX
#undef INTERP_MULTITEX
#undef TEX_UNIT_LOOP
#undef S_SCALE
#undef T_SCALE
#undef FixedToDepth
#undef ColorTemp
#undef GLinterp
#undef InterpToInt
#undef INTERP_ONE
#undef NAME
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