diff options
author | daryll <daryll> | 1999-12-05 23:10:25 +0000 |
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committer | daryll <daryll> | 1999-12-05 23:10:25 +0000 |
commit | 18c2681f29278bfbba32425ed0c3aa0d23fefed0 (patch) | |
tree | c508a99a7784ec70684309134498c3dc7990618a /xc/extras/Mesa/src/tritemp.h | |
parent | 98a9d17c5ef18d418ea7769f3f1932ec7f98c3c3 (diff) |
First DRI release of 3dfx driver.
Diffstat (limited to 'xc/extras/Mesa/src/tritemp.h')
-rw-r--r-- | xc/extras/Mesa/src/tritemp.h | 1066 |
1 files changed, 1066 insertions, 0 deletions
diff --git a/xc/extras/Mesa/src/tritemp.h b/xc/extras/Mesa/src/tritemp.h new file mode 100644 index 000000000..bc38bc9b9 --- /dev/null +++ b/xc/extras/Mesa/src/tritemp.h @@ -0,0 +1,1066 @@ +/* $Id: tritemp.h,v 1.1 1999/12/05 23:10:27 daryll Exp $ */ + +/* + * Mesa 3-D graphics library + * Version: 3.1 + * + * Copyright (C) 1999 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +/* + * Triangle Rasterizer Template + * + * This file is #include'd to generate custom triangle rasterizers. + * + * The following macros may be defined to indicate what auxillary information + * must be interplated across the triangle: + * INTERP_Z - if defined, interpolate Z values + * INTERP_RGB - if defined, interpolate RGB values + * INTERP_SPEC - if defined, interpolate specular RGB values + * INTERP_ALPHA - if defined, interpolate Alpha values + * INTERP_INDEX - if defined, interpolate color index values + * INTERP_INT_ST - if defined, interpolate integer ST texcoords + * (fast, simple 2-D texture mapping) + * INTERP_STUV - if defined, interpolate set 0 float STRQ texcoords + * NOTE: OpenGL STRQ = Mesa STUV (R was taken for red) + * INTERP_STUV1 - if defined, interpolate set 1 float 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. + * + * Optionally, one may provide one-time setup code per triangle: + * SETUP_CODE - code which is to be executed once per triangle + * + * The following macro MUST be defined: + * INNER_LOOP(LEFT,RIGHT,Y) - code to write a span of pixels. + * Something like: + * + * for (x=LEFT; x<RIGHT;x++) { + * put_pixel(x,Y); + * // increment fixed point interpolants + * } + * + * This code was designed for the origin to be in the lower-left corner. + * + * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen! + */ + + +/*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/ +{ + typedef struct { + GLint v0, v1; /* Y(v0) < Y(v1) */ + GLfloat dx; /* X(v1) - X(v0) */ + GLfloat dy; /* Y(v1) - Y(v0) */ + GLfixed fdxdy; /* dx/dy in fixed-point */ + GLfixed fsx; /* first sample point x coord */ + GLfixed fsy; + GLfloat adjy; /* adjust from v[0]->fy to fsy, scaled */ + GLint lines; /* number of lines to be sampled on this edge */ + GLfixed fx0; /* fixed pt X of lower endpoint */ + } EdgeT; + + struct vertex_buffer *VB = ctx->VB; + EdgeT eMaj, eTop, eBot; + GLfloat oneOverArea; + int vMin, vMid, vMax; /* vertex indexes: Y(vMin)<=Y(vMid)<=Y(vMax) */ + float bf = ctx->backface_sign; + + /* find the order of the 3 vertices along the Y axis */ + { + GLfloat y0 = VB->Win.data[v0][1]; + GLfloat y1 = VB->Win.data[v1][1]; + GLfloat y2 = VB->Win.data[v2][1]; + + if (y0<=y1) { + if (y1<=y2) { + vMin = v0; vMid = v1; vMax = v2; /* y0<=y1<=y2 */ + } + else if (y2<=y0) { + vMin = v2; vMid = v0; vMax = v1; /* y2<=y0<=y1 */ + } + else { + vMin = v0; vMid = v2; vMax = v1; bf = -bf; /* y0<=y2<=y1 */ + } + } + else { + if (y0<=y2) { + vMin = v1; vMid = v0; vMax = v2; bf = -bf; /* y1<=y0<=y2 */ + } + else if (y2<=y1) { + vMin = v2; vMid = v1; vMax = v0; bf = -bf; /* y2<=y1<=y0 */ + } + else { + vMin = v1; vMid = v2; vMax = v0; /* y1<=y2<=y0 */ + } + } + } + + /* vertex/edge relationship */ + eMaj.v0 = vMin; eMaj.v1 = vMax; /*TODO: .v1's not needed */ + eTop.v0 = vMid; eTop.v1 = vMax; + eBot.v0 = vMin; eBot.v1 = vMid; + + /* compute deltas for each edge: vertex[v1] - vertex[v0] */ + eMaj.dx = VB->Win.data[vMax][0] - VB->Win.data[vMin][0]; + eMaj.dy = VB->Win.data[vMax][1] - VB->Win.data[vMin][1]; + eTop.dx = VB->Win.data[vMax][0] - VB->Win.data[vMid][0]; + eTop.dy = VB->Win.data[vMax][1] - VB->Win.data[vMid][1]; + eBot.dx = VB->Win.data[vMid][0] - VB->Win.data[vMin][0]; + eBot.dy = VB->Win.data[vMid][1] - VB->Win.data[vMin][1]; + + /* compute oneOverArea */ + { + GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy; + + /* Do backface culling */ + if ( + area * bf < 0 || + area * area < .0025 + ) + return; + + + oneOverArea = 1.0F / area; + } + + /* Edge setup. For a triangle strip these could be reused... */ + { + /* fixed point Y coordinates */ + GLfixed vMin_fx = FloatToFixed(VB->Win.data[vMin][0] + 0.5F); + GLfixed vMin_fy = FloatToFixed(VB->Win.data[vMin][1] - 0.5F); + GLfixed vMid_fx = FloatToFixed(VB->Win.data[vMid][0] + 0.5F); + GLfixed vMid_fy = FloatToFixed(VB->Win.data[vMid][1] - 0.5F); + GLfixed vMax_fy = FloatToFixed(VB->Win.data[vMax][1] - 0.5F); + + eMaj.fsy = FixedCeil(vMin_fy); + eMaj.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eMaj.fsy); + if (eMaj.lines > 0) { + GLfloat dxdy = eMaj.dx / eMaj.dy; + eMaj.fdxdy = SignedFloatToFixed(dxdy); + eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy); /* SCALED! */ + eMaj.fx0 = vMin_fx; + eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * dxdy); + } + else { + return; /*CULLED*/ + } + + eTop.fsy = FixedCeil(vMid_fy); + eTop.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eTop.fsy); + if (eTop.lines > 0) { + GLfloat dxdy = eTop.dx / eTop.dy; + eTop.fdxdy = SignedFloatToFixed(dxdy); + eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */ + eTop.fx0 = vMid_fx; + eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * dxdy); + } + + eBot.fsy = FixedCeil(vMin_fy); + eBot.lines = FixedToInt(vMid_fy + FIXED_ONE - FIXED_EPSILON - eBot.fsy); + if (eBot.lines > 0) { + GLfloat dxdy = eBot.dx / eBot.dy; + eBot.fdxdy = SignedFloatToFixed(dxdy); + eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy); /* SCALED! */ + eBot.fx0 = vMin_fx; + eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * dxdy); + } + } + + /* + * Conceptually, we view a triangle as two subtriangles + * separated by a perfectly horizontal line. The edge that is + * intersected by this line is one with maximal absolute dy; we + * call it a ``major'' edge. The other two edges are the + * ``top'' edge (for the upper subtriangle) and the ``bottom'' + * edge (for the lower subtriangle). If either of these two + * edges is horizontal or very close to horizontal, the + * corresponding subtriangle might cover zero sample points; + * we take care to handle such cases, for performance as well + * as correctness. + * + * By stepping rasterization parameters along the major edge, + * we can avoid recomputing them at the discontinuity where + * the top and bottom edges meet. However, this forces us to + * be able to scan both left-to-right and right-to-left. + * Also, we must determine whether the major edge is at the + * left or right side of the triangle. We do this by + * computing the magnitude of the cross-product of the major + * and top edges. Since this magnitude depends on the sine of + * the angle between the two edges, its sign tells us whether + * we turn to the left or to the right when travelling along + * the major edge to the top edge, and from this we infer + * whether the major edge is on the left or the right. + * + * Serendipitously, this cross-product magnitude is also a + * value we need to compute the iteration parameter + * derivatives for the triangle, and it can be used to perform + * backface culling because its sign tells us whether the + * triangle is clockwise or counterclockwise. In this code we + * refer to it as ``area'' because it's also proportional to + * the pixel area of the triangle. + */ + + { + GLint ltor; /* true if scanning left-to-right */ +#if INTERP_Z + GLfloat dzdx, dzdy; GLfixed fdzdx; +#endif +#if INTERP_RGB + GLfloat drdx, drdy; GLfixed fdrdx; + GLfloat dgdx, dgdy; GLfixed fdgdx; + GLfloat dbdx, dbdy; GLfixed fdbdx; +#endif +#if INTERP_SPEC + GLfloat dsrdx, dsrdy; GLfixed fdsrdx; + GLfloat dsgdx, dsgdy; GLfixed fdsgdx; + GLfloat dsbdx, dsbdy; GLfixed fdsbdx; +#endif +#if INTERP_ALPHA + GLfloat dadx, dady; GLfixed fdadx; +#endif +#if INTERP_INDEX + GLfloat didx, didy; GLfixed fdidx; +#endif +#if INTERP_INT_ST + GLfloat dsdx, dsdy; GLfixed fdsdx; + GLfloat dtdx, dtdy; GLfixed fdtdx; +#endif +#if INTERP_STUV + GLfloat dsdx, dsdy; + GLfloat dtdx, dtdy; + GLfloat dudx, dudy; + GLfloat dvdx, dvdy; +#endif +#if INTERP_STUV1 + GLfloat ds1dx, ds1dy; + GLfloat dt1dx, dt1dy; + GLfloat du1dx, du1dy; + GLfloat dv1dx, dv1dy; +#endif + + /* + * Execute user-supplied setup code + */ +#ifdef SETUP_CODE + SETUP_CODE +#endif + + ltor = (oneOverArea < 0.0F); + + /* compute d?/dx and d?/dy derivatives */ +#if INTERP_Z + { + GLfloat eMaj_dz, eBot_dz; + eMaj_dz = VB->Win.data[vMax][2] - VB->Win.data[vMin][2]; + eBot_dz = VB->Win.data[vMid][2] - VB->Win.data[vMin][2]; + dzdx = oneOverArea * (eMaj_dz * eBot.dy - eMaj.dy * eBot_dz); + if (dzdx>DEPTH_SCALE || dzdx<-DEPTH_SCALE) { + /* probably a sliver triangle */ + dzdx = 0.0; + dzdy = 0.0; + } + else { + dzdy = oneOverArea * (eMaj.dx * eBot_dz - eMaj_dz * eBot.dx); + } +#if DEPTH_BITS==16 + fdzdx = SignedFloatToFixed(dzdx); +#else + fdzdx = (GLint) dzdx; +#endif + } +#endif +#if INTERP_RGB + { + GLfloat eMaj_dr, eBot_dr; + eMaj_dr = (GLint) VB->ColorPtr->data[vMax][0] - (GLint) VB->ColorPtr->data[vMin][0]; + eBot_dr = (GLint) VB->ColorPtr->data[vMid][0] - (GLint) VB->ColorPtr->data[vMin][0]; + drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr); + fdrdx = SignedFloatToFixed(drdx); + drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx); + } + { + GLfloat eMaj_dg, eBot_dg; + eMaj_dg = (GLint) VB->ColorPtr->data[vMax][1] - (GLint) VB->ColorPtr->data[vMin][1]; + eBot_dg = (GLint) VB->ColorPtr->data[vMid][1] - (GLint) VB->ColorPtr->data[vMin][1]; + dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg); + fdgdx = SignedFloatToFixed(dgdx); + dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx); + } + { + GLfloat eMaj_db, eBot_db; + eMaj_db = (GLint) VB->ColorPtr->data[vMax][2] - (GLint) VB->ColorPtr->data[vMin][2]; + eBot_db = (GLint) VB->ColorPtr->data[vMid][2] - (GLint) VB->ColorPtr->data[vMin][2]; + dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db); + fdbdx = SignedFloatToFixed(dbdx); + dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx); + } +#endif +#if INTERP_SPEC + { + GLfloat eMaj_dsr, eBot_dsr; + eMaj_dsr = (GLint) VB->Specular[vMax][0] - (GLint) VB->Specular[vMin][0]; + eBot_dsr = (GLint) VB->Specular[vMid][0] - (GLint) VB->Specular[vMin][0]; + dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr); + fdsrdx = SignedFloatToFixed(dsrdx); + dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx); + } + { + GLfloat eMaj_dsg, eBot_dsg; + eMaj_dsg = (GLint) VB->Specular[vMax][1] - (GLint) VB->Specular[vMin][1]; + eBot_dsg = (GLint) VB->Specular[vMid][1] - (GLint) VB->Specular[vMin][1]; + dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg); + fdsgdx = SignedFloatToFixed(dsgdx); + dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx); + } + { + GLfloat eMaj_dsb, eBot_dsb; + eMaj_dsb = (GLint) VB->Specular[vMax][2] - (GLint) VB->Specular[vMin][2]; + eBot_dsb = (GLint) VB->Specular[vMid][2] - (GLint) VB->Specular[vMin][2]; + dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb); + fdsbdx = SignedFloatToFixed(dsbdx); + dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx); + } +#endif +#if INTERP_ALPHA + { + GLfloat eMaj_da, eBot_da; + eMaj_da = (GLint) VB->ColorPtr->data[vMax][3] - (GLint) VB->ColorPtr->data[vMin][3]; + eBot_da = (GLint) VB->ColorPtr->data[vMid][3] - (GLint) VB->ColorPtr->data[vMin][3]; + dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da); + fdadx = SignedFloatToFixed(dadx); + dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx); + } +#endif +#if INTERP_INDEX + { + GLfloat eMaj_di, eBot_di; + eMaj_di = (GLint) VB->IndexPtr->data[vMax] - (GLint) VB->IndexPtr->data[vMin]; + eBot_di = (GLint) VB->IndexPtr->data[vMid] - (GLint) VB->IndexPtr->data[vMin]; + didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di); + fdidx = SignedFloatToFixed(didx); + didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx); + } +#endif +#if INTERP_INT_ST + { + GLfloat eMaj_ds, eBot_ds; + eMaj_ds = (VB->TexCoordPtr[0]->data[vMax][0] - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE; + eBot_ds = (VB->TexCoordPtr[0]->data[vMid][0] - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE; + dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds); + fdsdx = SignedFloatToFixed(dsdx); + dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx); + } + if (VB->TexCoordPtr[0]->size > 1) + { + GLfloat eMaj_dt, eBot_dt; + eMaj_dt = (VB->TexCoordPtr[0]->data[vMax][1] - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE; + eBot_dt = (VB->TexCoordPtr[0]->data[vMid][1] - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE; + dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt); + fdtdx = SignedFloatToFixed(dtdx); + dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx); + } else { + dtdx = 0; + fdtdx = SignedFloatToFixed(dtdx); + dtdy = 0; + } + +#endif +#if INTERP_STUV + { + GLfloat wMax = VB->Win.data[vMax][3]; + GLfloat wMin = VB->Win.data[vMin][3]; + GLfloat wMid = VB->Win.data[vMid][3]; + GLfloat eMaj_ds, eBot_ds; + GLfloat eMaj_dt, eBot_dt; + GLfloat eMaj_du, eBot_du; + GLfloat eMaj_dv, eBot_dv; + + eMaj_ds = VB->TexCoordPtr[0]->data[vMax][0]*wMax - VB->TexCoordPtr[0]->data[vMin][0]*wMin; + eBot_ds = VB->TexCoordPtr[0]->data[vMid][0]*wMid - VB->TexCoordPtr[0]->data[vMin][0]*wMin; + dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds); + dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx); + + + if (VB->TexCoordPtr[0]->size > 1) + { + eMaj_dt = VB->TexCoordPtr[0]->data[vMax][1]*wMax - VB->TexCoordPtr[0]->data[vMin][1]*wMin; + eBot_dt = VB->TexCoordPtr[0]->data[vMid][1]*wMid - VB->TexCoordPtr[0]->data[vMin][1]*wMin; + dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt); + dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx); + } else { + dtdx = 0; + dtdy = 0; + } + + if (VB->TexCoordPtr[0]->size > 2) + { + eMaj_du = VB->TexCoordPtr[0]->data[vMax][2]*wMax - VB->TexCoordPtr[0]->data[vMin][2]*wMin; + eBot_du = VB->TexCoordPtr[0]->data[vMid][2]*wMid - VB->TexCoordPtr[0]->data[vMin][2]*wMin; + dudx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du); + dudy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx); + } else { + dudx = 0; + dudy = 0; + } + + if (VB->TexCoordPtr[0]->size > 3) + { + eMaj_dv = VB->TexCoordPtr[0]->data[vMax][3]*wMax - VB->TexCoordPtr[0]->data[vMin][3]*wMin; + eBot_dv = VB->TexCoordPtr[0]->data[vMid][3]*wMid - VB->TexCoordPtr[0]->data[vMin][3]*wMin; + dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); + dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx); + } else { + eMaj_dv = wMax - wMin; + eBot_dv = wMid - wMin; + dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); + dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx); + } + } +#endif +#if INTERP_STUV1 + { + GLfloat wMax = VB->Win.data[vMax][3]; + GLfloat wMin = VB->Win.data[vMin][3]; + GLfloat wMid = VB->Win.data[vMid][3]; + GLfloat eMaj_ds, eBot_ds; + GLfloat eMaj_dt, eBot_dt; + GLfloat eMaj_du, eBot_du; + GLfloat eMaj_dv, eBot_dv; + eMaj_ds = VB->TexCoordPtr[1]->data[vMax][0]*wMax - VB->TexCoordPtr[1]->data[vMin][0]*wMin; + eBot_ds = VB->TexCoordPtr[1]->data[vMid][0]*wMid - VB->TexCoordPtr[1]->data[vMin][0]*wMin; + ds1dx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds); + ds1dy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx); + + if (VB->TexCoordPtr[1]->size > 1) + { + eMaj_dt = VB->TexCoordPtr[1]->data[vMax][1]*wMax - VB->TexCoordPtr[1]->data[vMin][1]*wMin; + eBot_dt = VB->TexCoordPtr[1]->data[vMid][1]*wMid - VB->TexCoordPtr[1]->data[vMin][1]*wMin; + dt1dx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt); + dt1dy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx); + } + else + { + dt1dx = 0; + dt1dy = 0; + } + + if (VB->TexCoordPtr[1]->size > 2) + { + eMaj_du = VB->TexCoordPtr[1]->data[vMax][2]*wMax - VB->TexCoordPtr[1]->data[vMin][2]*wMin; + eBot_du = VB->TexCoordPtr[1]->data[vMid][2]*wMid - VB->TexCoordPtr[1]->data[vMin][2]*wMin; + du1dx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du); + du1dy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx); + } + else + { + du1dx = 0; + du1dy = 0; + } + + if (VB->TexCoordPtr[1]->size > 3) + { + eMaj_dv = VB->TexCoordPtr[1]->data[vMax][3]*wMax - VB->TexCoordPtr[1]->data[vMin][3]*wMin; + eBot_dv = VB->TexCoordPtr[1]->data[vMid][3]*wMid - VB->TexCoordPtr[1]->data[vMin][3]*wMin; + dv1dx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); + dv1dy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx); + } + else + { + eMaj_dv = wMax - wMin; + eBot_dv = wMid - wMin; + dv1dx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); + dv1dy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx); + } + } +#endif + + /* + * We always sample at pixel centers. However, we avoid + * explicit half-pixel offsets in this code by incorporating + * the proper offset in each of x and y during the + * transformation to window coordinates. + * + * We also apply the usual rasterization rules to prevent + * cracks and overlaps. A pixel is considered inside a + * subtriangle if it meets all of four conditions: it is on or + * to the right of the left edge, strictly to the left of the + * right edge, on or below the top edge, and strictly above + * the bottom edge. (Some edges may be degenerate.) + * + * The following discussion assumes left-to-right scanning + * (that is, the major edge is on the left); the right-to-left + * case is a straightforward variation. + * + * We start by finding the half-integral y coordinate that is + * at or below the top of the triangle. This gives us the + * first scan line that could possibly contain pixels that are + * inside the triangle. + * + * Next we creep down the major edge until we reach that y, + * and compute the corresponding x coordinate on the edge. + * Then we find the half-integral x that lies on or just + * inside the edge. This is the first pixel that might lie in + * the interior of the triangle. (We won't know for sure + * until we check the other edges.) + * + * As we rasterize the triangle, we'll step down the major + * edge. For each step in y, we'll move an integer number + * of steps in x. There are two possible x step sizes, which + * we'll call the ``inner'' step (guaranteed to land on the + * edge or inside it) and the ``outer'' step (guaranteed to + * land on the edge or outside it). The inner and outer steps + * differ by one. During rasterization we maintain an error + * term that indicates our distance from the true edge, and + * select either the inner step or the outer step, whichever + * gets us to the first pixel that falls inside the triangle. + * + * All parameters (z, red, etc.) as well as the buffer + * addresses for color and z have inner and outer step values, + * so that we can increment them appropriately. This method + * eliminates the need to adjust parameters by creeping a + * sub-pixel amount into the triangle at each scanline. + */ + + { + int subTriangle; + GLfixed fx, fxLeftEdge, fxRightEdge, fdxLeftEdge, fdxRightEdge; + GLfixed fdxOuter; + int idxOuter; + float dxOuter; + GLfixed fError, fdError; + float adjx, adjy; + GLfixed fy; + int iy; +#ifdef PIXEL_ADDRESS + PIXEL_TYPE *pRow; + int dPRowOuter, dPRowInner; /* offset in bytes */ +#endif +#if INTERP_Z + GLdepth *zRow; + int dZRowOuter, dZRowInner; /* offset in bytes */ + GLfixed fz, fdzOuter, fdzInner; +#endif +#if INTERP_RGB + GLfixed fr, fdrOuter, fdrInner; + GLfixed fg, fdgOuter, fdgInner; + GLfixed fb, fdbOuter, fdbInner; +#endif +#if INTERP_SPEC + GLfixed fsr, fdsrOuter, fdsrInner; + GLfixed fsg, fdsgOuter, fdsgInner; + GLfixed fsb, fdsbOuter, fdsbInner; +#endif +#if INTERP_ALPHA + GLfixed fa, fdaOuter, fdaInner; +#endif +#if INTERP_INDEX + GLfixed fi, fdiOuter, fdiInner; +#endif +#if INTERP_INT_ST + GLfixed fs, fdsOuter, fdsInner; + GLfixed ft, fdtOuter, fdtInner; +#endif +#if INTERP_STUV + GLfloat sLeft, dsOuter, dsInner; + GLfloat tLeft, dtOuter, dtInner; + GLfloat uLeft, duOuter, duInner; + GLfloat vLeft, dvOuter, dvInner; +#endif +#if INTERP_STUV1 + GLfloat s1Left, ds1Outer, ds1Inner; + GLfloat t1Left, dt1Outer, dt1Inner; + GLfloat u1Left, du1Outer, du1Inner; + GLfloat v1Left, dv1Outer, dv1Inner; +#endif + + for (subTriangle=0; subTriangle<=1; subTriangle++) { + EdgeT *eLeft, *eRight; + int setupLeft, setupRight; + int lines; + + if (subTriangle==0) { + /* bottom half */ + if (ltor) { + eLeft = &eMaj; + eRight = &eBot; + lines = eRight->lines; + setupLeft = 1; + setupRight = 1; + } + else { + eLeft = &eBot; + eRight = &eMaj; + lines = eLeft->lines; + setupLeft = 1; + setupRight = 1; + } + } + else { + /* top half */ + if (ltor) { + eLeft = &eMaj; + eRight = &eTop; + lines = eRight->lines; + setupLeft = 0; + setupRight = 1; + } + else { + eLeft = &eTop; + eRight = &eMaj; + lines = eLeft->lines; + setupLeft = 1; + setupRight = 0; + } + if (lines==0) return; + } + + if (setupLeft && eLeft->lines>0) { + GLint vLower; + GLfixed fsx = eLeft->fsx; + fx = FixedCeil(fsx); + fError = fx - fsx - FIXED_ONE; + fxLeftEdge = fsx - FIXED_EPSILON; + fdxLeftEdge = eLeft->fdxdy; + fdxOuter = FixedFloor(fdxLeftEdge - FIXED_EPSILON); + fdError = fdxOuter - fdxLeftEdge + FIXED_ONE; + idxOuter = FixedToInt(fdxOuter); + dxOuter = (float) idxOuter; + (void) dxOuter; + + fy = eLeft->fsy; + iy = FixedToInt(fy); + + adjx = (float)(fx - eLeft->fx0); /* SCALED! */ + adjy = eLeft->adjy; /* SCALED! */ + (void) adjx; /* silence compiler warnings */ + (void) adjy; /* silence compiler warnings */ + + vLower = eLeft->v0; + (void) vLower; /* silence compiler warnings */ + +#ifdef PIXEL_ADDRESS + { + pRow = PIXEL_ADDRESS( FixedToInt(fxLeftEdge), iy ); + dPRowOuter = -((int)BYTES_PER_ROW) + idxOuter * sizeof(PIXEL_TYPE); + /* negative because Y=0 at bottom and increases upward */ + } +#endif + /* + * Now we need the set of parameter (z, color, etc.) values at + * the point (fx, fy). This gives us properly-sampled parameter + * values that we can step from pixel to pixel. Furthermore, + * although we might have intermediate results that overflow + * the normal parameter range when we step temporarily outside + * the triangle, we shouldn't overflow or underflow for any + * pixel that's actually inside the triangle. + */ + +#if INTERP_Z + { + GLfloat z0, tmp; + z0 = VB->Win.data[vLower][2] + ctx->PolygonZoffset; +#if DEPTH_BITS==16 + /* interpolate fixed-pt values */ + tmp = (z0 * FIXED_SCALE + dzdx * adjx + dzdy * adjy) + FIXED_HALF; + if (tmp < MAX_GLUINT/2) + fz = (GLfixed) tmp; + else + fz = MAX_GLUINT/2; + fdzOuter = SignedFloatToFixed(dzdy + dxOuter * dzdx); +#else + (void) tmp; + /* interpolate depth values exactly */ + fz = (GLint) (z0 + dzdx*FixedToFloat(adjx) + dzdy*FixedToFloat(adjy)); + fdzOuter = (GLint) (dzdy + dxOuter * dzdx); +#endif + zRow = Z_ADDRESS( ctx, FixedToInt(fxLeftEdge), iy ); + dZRowOuter = (ctx->Buffer->Width + idxOuter) * sizeof(GLdepth); + } +#endif +#if INTERP_RGB + fr = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][0]) + drdx * adjx + drdy * adjy) + + FIXED_HALF; + fdrOuter = SignedFloatToFixed(drdy + dxOuter * drdx); + + fg = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][1]) + dgdx * adjx + dgdy * adjy) + + FIXED_HALF; + fdgOuter = SignedFloatToFixed(dgdy + dxOuter * dgdx); + + fb = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][2]) + dbdx * adjx + dbdy * adjy) + + FIXED_HALF; + fdbOuter = SignedFloatToFixed(dbdy + dxOuter * dbdx); +#endif +#if INTERP_SPEC + fsr = (GLfixed)(IntToFixed(VB->Specular[vLower][0]) + dsrdx * adjx + dsrdy * adjy) + + FIXED_HALF; + fdsrOuter = SignedFloatToFixed(dsrdy + dxOuter * dsrdx); + + fsg = (GLfixed)(IntToFixed(VB->Specular[vLower][1]) + dsgdx * adjx + dsgdy * adjy) + + FIXED_HALF; + fdsgOuter = SignedFloatToFixed(dsgdy + dxOuter * dsgdx); + + fsb = (GLfixed)(IntToFixed(VB->Specular[vLower][2]) + dsbdx * adjx + dsbdy * adjy) + + FIXED_HALF; + fdsbOuter = SignedFloatToFixed(dsbdy + dxOuter * dsbdx); +#endif +#if INTERP_ALPHA + fa = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][3]) + dadx * adjx + dady * adjy) + + FIXED_HALF; + fdaOuter = SignedFloatToFixed(dady + dxOuter * dadx); +#endif +#if INTERP_INDEX + fi = (GLfixed)(VB->IndexPtr->data[vLower] * FIXED_SCALE + didx * adjx + + didy * adjy) + FIXED_HALF; + fdiOuter = SignedFloatToFixed(didy + dxOuter * didx); +#endif +#if INTERP_INT_ST + { + GLfloat s0, t0; + s0 = VB->TexCoordPtr[0]->data[vLower][0] * S_SCALE; + fs = (GLfixed)(s0 * FIXED_SCALE + dsdx * adjx + dsdy * adjy) + FIXED_HALF; + fdsOuter = SignedFloatToFixed(dsdy + dxOuter * dsdx); + + if (VB->TexCoordPtr[0]->size > 1) + { + t0 = VB->TexCoordPtr[0]->data[vLower][1] * T_SCALE; + ft = (GLfixed)(t0 * FIXED_SCALE + dtdx * adjx + dtdy * adjy) + FIXED_HALF; + fdtOuter = SignedFloatToFixed(dtdy + dxOuter * dtdx); + } + else + { + t0 = 0; + ft = (GLfixed) FIXED_HALF; + fdtOuter = SignedFloatToFixed(0); + } + } +#endif +#if INTERP_STUV + { + GLfloat invW = VB->Win.data[vLower][3]; + GLfloat s0, t0, u0, v0; + s0 = VB->TexCoordPtr[0]->data[vLower][0] * invW; + sLeft = s0 + (dsdx * adjx + dsdy * adjy) * (1.0F/FIXED_SCALE); + dsOuter = dsdy + dxOuter * dsdx; + if (VB->TexCoordPtr[0]->size > 1) + { + t0 = VB->TexCoordPtr[0]->data[vLower][1] * invW; + tLeft = t0 + (dtdx * adjx + dtdy * adjy) * (1.0F/FIXED_SCALE); + dtOuter = dtdy + dxOuter * dtdx; + } else { + tLeft = dtOuter = 0; + } + if (VB->TexCoordPtr[0]->size > 2) + { + u0 = VB->TexCoordPtr[0]->data[vLower][2] * invW; + uLeft = u0 + (dudx * adjx + dudy * adjy) * (1.0F/FIXED_SCALE); + duOuter = dudy + dxOuter * dudx; + } else { + uLeft = duOuter = 0; + } + if (VB->TexCoordPtr[0]->size > 3) + { + v0 = VB->TexCoordPtr[0]->data[vLower][3] * invW; + } else { + v0 = invW; + } + vLeft = v0 + (dvdx * adjx + dvdy * adjy) * (1.0F/FIXED_SCALE); + dvOuter = dvdy + dxOuter * dvdx; + } +#endif +#if INTERP_STUV1 + { + GLfloat invW = VB->Win.data[vLower][3]; + GLfloat s0, t0, u0, v0; + s0 = VB->TexCoordPtr[1]->data[vLower][0] * invW; + s1Left = s0 + (ds1dx * adjx + ds1dy * adjy) * (1.0F/FIXED_SCALE); + ds1Outer = ds1dy + dxOuter * ds1dx; + if (VB->TexCoordPtr[0]->size > 1) + { + t0 = VB->TexCoordPtr[1]->data[vLower][1] * invW; + t1Left = t0 + (dt1dx * adjx + dt1dy * adjy) * (1.0F/FIXED_SCALE); + dt1Outer = dt1dy + dxOuter * dt1dx; + } else { + t1Left = dt1Outer = 0; + } + if (VB->TexCoordPtr[0]->size > 2) + { + u0 = VB->TexCoordPtr[1]->data[vLower][2] * invW; + u1Left = u0 + (du1dx * adjx + du1dy * adjy) * (1.0F/FIXED_SCALE); + du1Outer = du1dy + dxOuter * du1dx; + } else { + u1Left = du1Outer = 0; + } + if (VB->TexCoordPtr[0]->size > 3) + { + v0 = VB->TexCoordPtr[1]->data[vLower][3] * invW; + } else { + v0 = invW; + } + v1Left = v0 + (dv1dx * adjx + dv1dy * adjy) * (1.0F/FIXED_SCALE); + dv1Outer = dv1dy + dxOuter * dv1dx; + } +#endif + + } /*if setupLeft*/ + + + if (setupRight && eRight->lines>0) { + fxRightEdge = eRight->fsx - FIXED_EPSILON; + fdxRightEdge = eRight->fdxdy; + } + + if (lines==0) { + continue; + } + + + /* Rasterize setup */ +#ifdef PIXEL_ADDRESS + dPRowInner = dPRowOuter + sizeof(PIXEL_TYPE); +#endif +#if INTERP_Z + dZRowInner = dZRowOuter + sizeof(GLdepth); + fdzInner = fdzOuter + fdzdx; +#endif +#if INTERP_RGB + fdrInner = fdrOuter + fdrdx; + fdgInner = fdgOuter + fdgdx; + fdbInner = fdbOuter + fdbdx; +#endif +#if INTERP_SPEC + fdsrInner = fdsrOuter + fdsrdx; + fdsgInner = fdsgOuter + fdsgdx; + fdsbInner = fdsbOuter + fdsbdx; +#endif +#if INTERP_ALPHA + fdaInner = fdaOuter + fdadx; +#endif +#if INTERP_INDEX + fdiInner = fdiOuter + fdidx; +#endif +#if INTERP_INT_ST + fdsInner = fdsOuter + fdsdx; + fdtInner = fdtOuter + fdtdx; +#endif +#if INTERP_STUV + dsInner = dsOuter + dsdx; + dtInner = dtOuter + dtdx; + duInner = duOuter + dudx; + dvInner = dvOuter + dvdx; +#endif +#if INTERP_STUV1 + ds1Inner = ds1Outer + ds1dx; + dt1Inner = dt1Outer + dt1dx; + du1Inner = du1Outer + du1dx; + dv1Inner = dv1Outer + dv1dx; +#endif + + while (lines>0) { + /* initialize the span interpolants to the leftmost value */ + /* ff = fixed-pt fragment */ +#if INTERP_Z + GLfixed ffz = fz; + /*GLdepth *zp = zRow;*/ +#endif +#if INTERP_RGB + GLfixed ffr = fr, ffg = fg, ffb = fb; +#endif +#if INTERP_SPEC + GLfixed ffsr = fsr, ffsg = fsg, ffsb = fsb; +#endif +#if INTERP_ALPHA + GLfixed ffa = fa; +#endif +#if INTERP_INDEX + GLfixed ffi = fi; +#endif +#if INTERP_INT_ST + GLfixed ffs = fs, fft = ft; +#endif +#if INTERP_STUV + GLfloat ss = sLeft, tt = tLeft, uu = uLeft, vv = vLeft; +#endif +#if INTERP_STUV1 + GLfloat ss1 = s1Left, tt1 = t1Left, uu1 = u1Left, vv1 = v1Left; +#endif + GLint left = FixedToInt(fxLeftEdge); + GLint right = FixedToInt(fxRightEdge); + +#if INTERP_RGB + { + /* need this to accomodate round-off errors */ + GLfixed ffrend = ffr+(right-left-1)*fdrdx; + GLfixed ffgend = ffg+(right-left-1)*fdgdx; + GLfixed ffbend = ffb+(right-left-1)*fdbdx; + if (ffrend<0) ffr -= ffrend; + if (ffgend<0) ffg -= ffgend; + if (ffbend<0) ffb -= ffbend; + if (ffr<0) ffr = 0; + if (ffg<0) ffg = 0; + if (ffb<0) ffb = 0; + } +#endif +#if INTERP_SPEC + { + /* need this to accomodate round-off errors */ + GLfixed ffsrend = ffsr+(right-left-1)*fdsrdx; + GLfixed ffsgend = ffsg+(right-left-1)*fdsgdx; + GLfixed ffsbend = ffsb+(right-left-1)*fdsbdx; + if (ffsrend<0) ffsr -= ffsrend; + if (ffsgend<0) ffsg -= ffsgend; + if (ffsbend<0) ffsb -= ffsbend; + if (ffsr<0) ffsr = 0; + if (ffsg<0) ffsg = 0; + if (ffsb<0) ffsb = 0; + } +#endif +#if INTERP_ALPHA + { + GLfixed ffaend = ffa+(right-left-1)*fdadx; + if (ffaend<0) ffa -= ffaend; + if (ffa<0) ffa = 0; + } +#endif +#if INTERP_INDEX + if (ffi<0) ffi = 0; +#endif + + INNER_LOOP( left, right, iy ); + + /* + * Advance to the next scan line. Compute the + * new edge coordinates, and adjust the + * pixel-center x coordinate so that it stays + * on or inside the major edge. + */ + iy++; + lines--; + + fxLeftEdge += fdxLeftEdge; + fxRightEdge += fdxRightEdge; + + + fError += fdError; + if (fError >= 0) { + fError -= FIXED_ONE; +#ifdef PIXEL_ADDRESS + pRow = (PIXEL_TYPE*) ((GLubyte*)pRow + dPRowOuter); +#endif +#if INTERP_Z + zRow = (GLdepth*) ((GLubyte*)zRow + dZRowOuter); + fz += fdzOuter; +#endif +#if INTERP_RGB + fr += fdrOuter; fg += fdgOuter; fb += fdbOuter; +#endif +#if INTERP_SPEC + fsr += fdsrOuter; fsg += fdsgOuter; fsb += fdsbOuter; +#endif +#if INTERP_ALPHA + fa += fdaOuter; +#endif +#if INTERP_INDEX + fi += fdiOuter; +#endif +#if INTERP_INT_ST + fs += fdsOuter; ft += fdtOuter; +#endif +#if INTERP_STUV + sLeft += dsOuter; + tLeft += dtOuter; + uLeft += duOuter; + vLeft += dvOuter; +#endif +#if INTERP_STUV1 + s1Left += ds1Outer; + t1Left += dt1Outer; + u1Left += du1Outer; + v1Left += dv1Outer; +#endif + } + else { +#ifdef PIXEL_ADDRESS + pRow = (PIXEL_TYPE*) ((GLubyte*)pRow + dPRowInner); +#endif +#if INTERP_Z + zRow = (GLdepth*) ((GLubyte*)zRow + dZRowInner); + fz += fdzInner; +#endif +#if INTERP_RGB + fr += fdrInner; fg += fdgInner; fb += fdbInner; +#endif +#if INTERP_SPEC + fsr += fdsrInner; fsg += fdsgInner; fsb += fdsbInner; +#endif +#if INTERP_ALPHA + fa += fdaInner; +#endif +#if INTERP_INDEX + fi += fdiInner; +#endif +#if INTERP_INT_ST + fs += fdsInner; ft += fdtInner; +#endif +#if INTERP_STUV + sLeft += dsInner; + tLeft += dtInner; + uLeft += duInner; + vLeft += dvInner; +#endif +#if INTERP_STUV1 + s1Left += ds1Inner; + t1Left += dt1Inner; + u1Left += du1Inner; + v1Left += dv1Inner; +#endif + } + } /*while lines>0*/ + + } /* for subTriangle */ + + } + } +} + +#undef SETUP_CODE +#undef INNER_LOOP + +#undef PIXEL_TYPE +#undef BYTES_PER_ROW +#undef PIXEL_ADDRESS + +#undef INTERP_Z +#undef INTERP_RGB +#undef INTERP_SPEC +#undef INTERP_ALPHA +#undef INTERP_INDEX +#undef INTERP_INT_ST +#undef INTERP_STUV +#undef INTERP_STUV1 + +#undef S_SCALE +#undef T_SCALE |