006a9e008b
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
1330 lines
50 KiB
C
1330 lines
50 KiB
C
/*
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* Mesa 3-D graphics library
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* Version: 6.1
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*
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* Copyright (C) 1999-2004 Brian Paul All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* Triangle Rasterizer Template
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*
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* This file is #include'd to generate custom triangle rasterizers.
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*
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* The following macros may be defined to indicate what auxillary information
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* must be interplated across the triangle:
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* INTERP_Z - if defined, interpolate vertex Z values
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* INTERP_W - if defined, interpolate vertex W values
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* INTERP_FOG - if defined, interpolate fog values
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* INTERP_RGB - if defined, interpolate RGB values
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* INTERP_ALPHA - if defined, interpolate Alpha values (req's INTERP_RGB)
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* INTERP_SPEC - if defined, interpolate specular RGB values
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* INTERP_INDEX - if defined, interpolate color index values
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* INTERP_INT_TEX - if defined, interpolate integer ST texcoords
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* (fast, simple 2-D texture mapping)
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* INTERP_TEX - if defined, interpolate set 0 float STRQ texcoords
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* NOTE: OpenGL STRQ = Mesa STUV (R was taken for red)
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* INTERP_MULTITEX - if defined, interpolate N units of STRQ texcoords
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*
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* When one can directly address pixels in the color buffer the following
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* macros can be defined and used to compute pixel addresses during
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* rasterization (see pRow):
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* PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
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* BYTES_PER_ROW - number of bytes per row in the color buffer
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* PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
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* Y==0 at bottom of screen and increases upward.
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*
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* Similarly, for direct depth buffer access, this type is used for depth
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* buffer addressing:
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* DEPTH_TYPE - either GLushort or GLuint
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*
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* Optionally, one may provide one-time setup code per triangle:
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* SETUP_CODE - code which is to be executed once per triangle
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* CLEANUP_CODE - code to execute at end of triangle
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*
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* The following macro MUST be defined:
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* RENDER_SPAN(span) - code to write a span of pixels.
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*
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* This code was designed for the origin to be in the lower-left corner.
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*
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* Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen!
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*
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*
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* Some notes on rasterization accuracy:
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*
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* This code uses fixed point arithmetic (the GLfixed type) to iterate
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* over the triangle edges and interpolate ancillary data (such as Z,
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* color, secondary color, etc). The number of fractional bits in
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* GLfixed and the value of SUB_PIXEL_BITS has a direct bearing on the
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* accuracy of rasterization.
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*
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* If SUB_PIXEL_BITS=4 then we'll snap the vertices to the nearest
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* 1/16 of a pixel. If we're walking up a long, nearly vertical edge
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* (dx=1/16, dy=1024) we'll need 4 + 10 = 14 fractional bits in
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* GLfixed to walk the edge without error. If the maximum viewport
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* height is 4K pixels, then we'll need 4 + 12 = 16 fractional bits.
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*
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* Historically, Mesa has used 11 fractional bits in GLfixed, snaps
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* vertices to 1/16 pixel and allowed a maximum viewport height of 2K
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* pixels. 11 fractional bits is actually insufficient for accurately
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* rasterizing some triangles. More recently, the maximum viewport
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* height was increased to 4K pixels. Thus, Mesa should be using 16
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* fractional bits in GLfixed. Unfortunately, there may be some issues
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* with setting FIXED_FRAC_BITS=16, such as multiplication overflow.
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* This will have to be examined in some detail...
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*
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* For now, if you find rasterization errors, particularly with tall,
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* sliver triangles, try increasing FIXED_FRAC_BITS and/or decreasing
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* SUB_PIXEL_BITS.
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*/
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/*
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* ColorTemp is used for intermediate color values.
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*/
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#if CHAN_TYPE == GL_FLOAT
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#define ColorTemp GLfloat
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#else
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#define ColorTemp GLint /* same as GLfixed */
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#endif
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/*
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* Walk triangle edges with GLfixed or GLdouble
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*/
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#if TRIANGLE_WALK_DOUBLE
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#define GLinterp GLdouble
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#define InterpToInt(X) ((GLint) (X))
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#define INTERP_ONE 1.0
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#else
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#define GLinterp GLfixed
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#define InterpToInt(X) FixedToInt(X)
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#define INTERP_ONE FIXED_ONE
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#endif
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/*
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* Either loop over all texture units, or just use unit zero.
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*/
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#ifdef INTERP_MULTITEX
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#define TEX_UNIT_LOOP(CODE) \
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{ \
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GLuint u; \
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for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { \
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if (ctx->Texture._EnabledCoordUnits & (1 << u)) { \
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CODE \
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} \
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} \
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}
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#define INTERP_TEX
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#elif defined(INTERP_TEX)
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#define TEX_UNIT_LOOP(CODE) \
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{ \
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const GLuint u = 0; \
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CODE \
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}
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#endif
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static void NAME(GLcontext *ctx, const SWvertex *v0,
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const SWvertex *v1,
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const SWvertex *v2 )
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{
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typedef struct {
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const SWvertex *v0, *v1; /* Y(v0) < Y(v1) */
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#if TRIANGLE_WALK_DOUBLE
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GLdouble dx; /* X(v1) - X(v0) */
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GLdouble dy; /* Y(v1) - Y(v0) */
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GLdouble dxdy; /* dx/dy */
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GLdouble adjy; /* adjust from v[0]->fy to fsy, scaled */
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GLdouble fsx; /* first sample point x coord */
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GLdouble fsy;
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GLdouble fx0; /*X of lower endpoint */
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#else
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GLfloat dx; /* X(v1) - X(v0) */
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GLfloat dy; /* Y(v1) - Y(v0) */
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GLfloat dxdy; /* dx/dy */
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GLfixed fdxdy; /* dx/dy in fixed-point */
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GLfloat adjy; /* adjust from v[0]->fy to fsy, scaled */
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GLfixed fsx; /* first sample point x coord */
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GLfixed fsy;
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GLfixed fx0; /* fixed pt X of lower endpoint */
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#endif
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GLint lines; /* number of lines to be sampled on this edge */
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} EdgeT;
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#ifdef INTERP_Z
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const GLint depthBits = ctx->Visual.depthBits;
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const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0;
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const GLfloat maxDepth = ctx->DepthMaxF;
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#define FixedToDepth(F) ((F) >> fixedToDepthShift)
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#endif
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EdgeT eMaj, eTop, eBot;
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GLfloat oneOverArea;
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const SWvertex *vMin, *vMid, *vMax; /* Y(vMin)<=Y(vMid)<=Y(vMax) */
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GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceSign;
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#if !TRIANGLE_WALK_DOUBLE
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const GLint snapMask = ~((FIXED_ONE / (1 << SUB_PIXEL_BITS)) - 1); /* for x/y coord snapping */
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#endif
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GLinterp vMin_fx, vMin_fy, vMid_fx, vMid_fy, vMax_fx, vMax_fy;
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struct sw_span span;
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INIT_SPAN(span, GL_POLYGON, 0, 0, 0);
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#ifdef INTERP_Z
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(void) fixedToDepthShift;
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#endif
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/*
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printf("%s()\n", __FUNCTION__);
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printf(" %g, %g, %g\n", v0->win[0], v0->win[1], v0->win[2]);
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printf(" %g, %g, %g\n", v1->win[0], v1->win[1], v1->win[2]);
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printf(" %g, %g, %g\n", v2->win[0], v2->win[1], v2->win[2]);
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*/
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/*
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ASSERT(v0->win[2] >= 0.0);
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ASSERT(v1->win[2] >= 0.0);
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ASSERT(v2->win[2] >= 0.0);
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*/
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/* Compute fixed point x,y coords w/ half-pixel offsets and snapping.
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* And find the order of the 3 vertices along the Y axis.
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*/
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{
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#if TRIANGLE_WALK_DOUBLE
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const GLdouble fy0 = v0->win[1] - 0.5;
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const GLdouble fy1 = v1->win[1] - 0.5;
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const GLdouble fy2 = v2->win[1] - 0.5;
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#else
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const GLfixed fy0 = FloatToFixed(v0->win[1] - 0.5F) & snapMask;
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const GLfixed fy1 = FloatToFixed(v1->win[1] - 0.5F) & snapMask;
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const GLfixed fy2 = FloatToFixed(v2->win[1] - 0.5F) & snapMask;
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#endif
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if (fy0 <= fy1) {
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if (fy1 <= fy2) {
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/* y0 <= y1 <= y2 */
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vMin = v0; vMid = v1; vMax = v2;
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vMin_fy = fy0; vMid_fy = fy1; vMax_fy = fy2;
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}
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else if (fy2 <= fy0) {
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/* y2 <= y0 <= y1 */
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vMin = v2; vMid = v0; vMax = v1;
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vMin_fy = fy2; vMid_fy = fy0; vMax_fy = fy1;
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}
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else {
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/* y0 <= y2 <= y1 */
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vMin = v0; vMid = v2; vMax = v1;
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vMin_fy = fy0; vMid_fy = fy2; vMax_fy = fy1;
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bf = -bf;
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}
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}
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else {
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if (fy0 <= fy2) {
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/* y1 <= y0 <= y2 */
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vMin = v1; vMid = v0; vMax = v2;
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vMin_fy = fy1; vMid_fy = fy0; vMax_fy = fy2;
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bf = -bf;
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}
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else if (fy2 <= fy1) {
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/* y2 <= y1 <= y0 */
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vMin = v2; vMid = v1; vMax = v0;
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vMin_fy = fy2; vMid_fy = fy1; vMax_fy = fy0;
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bf = -bf;
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}
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else {
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/* y1 <= y2 <= y0 */
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vMin = v1; vMid = v2; vMax = v0;
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vMin_fy = fy1; vMid_fy = fy2; vMax_fy = fy0;
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}
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}
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/* fixed point X coords */
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#if TRIANGLE_WALK_DOUBLE
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vMin_fx = vMin->win[0] + 0.5;
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vMid_fx = vMid->win[0] + 0.5;
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vMax_fx = vMax->win[0] + 0.5;
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#else
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vMin_fx = FloatToFixed(vMin->win[0] + 0.5F) & snapMask;
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vMid_fx = FloatToFixed(vMid->win[0] + 0.5F) & snapMask;
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vMax_fx = FloatToFixed(vMax->win[0] + 0.5F) & snapMask;
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#endif
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}
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/* vertex/edge relationship */
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eMaj.v0 = vMin; eMaj.v1 = vMax; /*TODO: .v1's not needed */
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eTop.v0 = vMid; eTop.v1 = vMax;
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eBot.v0 = vMin; eBot.v1 = vMid;
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/* compute deltas for each edge: vertex[upper] - vertex[lower] */
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#if TRIANGLE_WALK_DOUBLE
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eMaj.dx = vMax_fx - vMin_fx;
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eMaj.dy = vMax_fy - vMin_fy;
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eTop.dx = vMax_fx - vMid_fx;
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eTop.dy = vMax_fy - vMid_fy;
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eBot.dx = vMid_fx - vMin_fx;
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eBot.dy = vMid_fy - vMin_fy;
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#else
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eMaj.dx = FixedToFloat(vMax_fx - vMin_fx);
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eMaj.dy = FixedToFloat(vMax_fy - vMin_fy);
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eTop.dx = FixedToFloat(vMax_fx - vMid_fx);
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eTop.dy = FixedToFloat(vMax_fy - vMid_fy);
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eBot.dx = FixedToFloat(vMid_fx - vMin_fx);
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eBot.dy = FixedToFloat(vMid_fy - vMin_fy);
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#endif
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/* compute area, oneOverArea and perform backface culling */
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{
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#if TRIANGLE_WALK_DOUBLE
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const GLdouble area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
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#else
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const GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
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#endif
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/* Do backface culling */
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if (area * bf < 0.0)
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return;
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if (IS_INF_OR_NAN(area) || area == 0.0F)
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return;
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oneOverArea = 1.0F / area;
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}
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span.facing = ctx->_Facing; /* for 2-sided stencil test */
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/* Edge setup. For a triangle strip these could be reused... */
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{
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#if TRIANGLE_WALK_DOUBLE
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eMaj.fsy = CEILF(vMin_fy);
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eMaj.lines = (GLint) CEILF(vMax_fy - eMaj.fsy);
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#else
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eMaj.fsy = FixedCeil(vMin_fy);
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eMaj.lines = FixedToInt(FixedCeil(vMax_fy - eMaj.fsy));
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#endif
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if (eMaj.lines > 0) {
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eMaj.dxdy = eMaj.dx / eMaj.dy;
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#if TRIANGLE_WALK_DOUBLE
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eMaj.adjy = (eMaj.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */
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eMaj.fx0 = vMin_fx;
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eMaj.fsx = eMaj.fx0 + (eMaj.adjy * eMaj.dxdy) / (GLdouble) FIXED_SCALE;
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#else
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eMaj.fdxdy = SignedFloatToFixed(eMaj.dxdy);
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eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy); /* SCALED! */
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eMaj.fx0 = vMin_fx;
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eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * eMaj.dxdy);
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#endif
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}
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else {
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return; /*CULLED*/
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}
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#if TRIANGLE_WALK_DOUBLE
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eTop.fsy = CEILF(vMid_fy);
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eTop.lines = (GLint) CEILF(vMax_fy - eTop.fsy);
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#else
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eTop.fsy = FixedCeil(vMid_fy);
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eTop.lines = FixedToInt(FixedCeil(vMax_fy - eTop.fsy));
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#endif
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if (eTop.lines > 0) {
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eTop.dxdy = eTop.dx / eTop.dy;
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#if TRIANGLE_WALK_DOUBLE
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eTop.adjy = (eTop.fsy - vMid_fy) * FIXED_SCALE; /* SCALED! */
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eTop.fx0 = vMid_fx;
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eTop.fsx = eTop.fx0 + (eTop.adjy * eTop.dxdy) / (GLdouble) FIXED_SCALE;
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#else
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eTop.fdxdy = SignedFloatToFixed(eTop.dxdy);
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eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */
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eTop.fx0 = vMid_fx;
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eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * eTop.dxdy);
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#endif
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}
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#if TRIANGLE_WALK_DOUBLE
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eBot.fsy = CEILF(vMin_fy);
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eBot.lines = (GLint) CEILF(vMid_fy - eBot.fsy);
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#else
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eBot.fsy = FixedCeil(vMin_fy);
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eBot.lines = FixedToInt(FixedCeil(vMid_fy - eBot.fsy));
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#endif
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if (eBot.lines > 0) {
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eBot.dxdy = eBot.dx / eBot.dy;
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#if TRIANGLE_WALK_DOUBLE
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eBot.adjy = (eBot.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */
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eBot.fx0 = vMin_fx;
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eBot.fsx = eBot.fx0 + (eBot.adjy * eBot.dxdy) / (GLdouble) FIXED_SCALE;
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#else
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eBot.fdxdy = SignedFloatToFixed(eBot.dxdy);
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eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy); /* SCALED! */
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eBot.fx0 = vMin_fx;
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eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * eBot.dxdy);
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#endif
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}
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}
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/*
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* Conceptually, we view a triangle as two subtriangles
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* separated by a perfectly horizontal line. The edge that is
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* intersected by this line is one with maximal absolute dy; we
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* call it a ``major'' edge. The other two edges are the
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* ``top'' edge (for the upper subtriangle) and the ``bottom''
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* edge (for the lower subtriangle). If either of these two
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* edges is horizontal or very close to horizontal, the
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* corresponding subtriangle might cover zero sample points;
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* we take care to handle such cases, for performance as well
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* as correctness.
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*
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* By stepping rasterization parameters along the major edge,
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* we can avoid recomputing them at the discontinuity where
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* the top and bottom edges meet. However, this forces us to
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* be able to scan both left-to-right and right-to-left.
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* Also, we must determine whether the major edge is at the
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* left or right side of the triangle. We do this by
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* computing the magnitude of the cross-product of the major
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* and top edges. Since this magnitude depends on the sine of
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* the angle between the two edges, its sign tells us whether
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* we turn to the left or to the right when travelling along
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* the major edge to the top edge, and from this we infer
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* whether the major edge is on the left or the right.
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*
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* Serendipitously, this cross-product magnitude is also a
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* value we need to compute the iteration parameter
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* derivatives for the triangle, and it can be used to perform
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* backface culling because its sign tells us whether the
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* triangle is clockwise or counterclockwise. In this code we
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* refer to it as ``area'' because it's also proportional to
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* the pixel area of the triangle.
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*/
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{
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GLint scan_from_left_to_right; /* true if scanning left-to-right */
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#ifdef INTERP_INDEX
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GLfloat didx, didy;
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#endif
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/*
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* Execute user-supplied setup code
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*/
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#ifdef SETUP_CODE
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SETUP_CODE
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#endif
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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
|