| |
| /* |
| * Mesa 3-D graphics library |
| * Version: 3.5 |
| * |
| * Copyright (C) 1999-2001 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. |
| * |
| * Authors: |
| * Keith Whitwell <keith_whitwell@yahoo.com> |
| */ |
| |
| /* Template to build clipping routines to support t_dd_imm_primtmp.h. |
| * |
| * The TAG(draw_line) and TAG(draw_triangle) routines are called in |
| * clipping and fallback scenarios, and when the native hardware |
| * primitive (eg polygons) is unavailable. |
| */ |
| |
| |
| #define CLIP_DOTPROD(K, A, B, C, D) \ |
| (CLIP_X(K)*A + CLIP_Y(K)*B + \ |
| CLIP_Z(K)*C + CLIP_W(K)*D) |
| |
| #define POLY_CLIP( PLANE, A, B, C, D ) \ |
| do { \ |
| if (mask & PLANE) { \ |
| TNL_VERTEX **indata = inlist[in]; \ |
| TNL_VERTEX **outdata = inlist[in ^= 1]; \ |
| TNL_VERTEX *J = indata[0]; \ |
| GLfloat dpJ = CLIP_DOTPROD(J, A, B, C, D ); \ |
| GLuint outcount = 0; \ |
| GLuint i; \ |
| \ |
| indata[n] = indata[0]; /* prevent rotation of vertices */ \ |
| for (i = 1; i <= n; i++) { \ |
| TNL_VERTEX *I = indata[i]; \ |
| GLfloat dpI = CLIP_DOTPROD(idx, A, B, C, D ); \ |
| \ |
| if (!NEGATIVE(dpPrev)) { \ |
| outdata[outcount++] = J; \ |
| } \ |
| \ |
| if (DIFFERENT_SIGNS(dpI, dpJ)) { \ |
| TNL_VERTEX *O = verts++; \ |
| outdata[outcount++] = O; \ |
| if (NEGATIVE(dpI)) { \ |
| /* Going out of bounds. Avoid division by zero as we \ |
| * know dp != dpPrev from DIFFERENT_SIGNS, above. \ |
| */ \ |
| GLfloat t = dpI / (dpI - dpJ); \ |
| INTERP( ctx, t, O, I, J ); \ |
| } else { \ |
| /* Coming back in. \ |
| */ \ |
| GLfloat t = dpJ / (dpJ - dpI); \ |
| INTERP( ctx, t, O, J, I ); \ |
| } \ |
| } \ |
| \ |
| J = I; \ |
| dpJ = dpI; \ |
| } \ |
| \ |
| if (outcount < 3) \ |
| return; \ |
| \ |
| nr = outcount; \ |
| } \ |
| } while (0) |
| |
| |
| #define LINE_CLIP(PLANE, A, B, C, D ) \ |
| do { \ |
| if (mask & PLANE) { \ |
| GLfloat dpI = CLIP_DOTPROD( I, A, B, C, D ); \ |
| GLfloat dpJ = CLIP_DOTPROD( J, A, B, C, D ); \ |
| \ |
| if (DIFFERENT_SIGNS(dpI, dpJ)) { \ |
| TNL_VERTEX *O = verts++; \ |
| if (NEGATIVE(dpJ)) { \ |
| GLfloat t = dpI / (dpI - dpJ); \ |
| INTERP( ctx, t, O, I, J ); \ |
| J = O; \ |
| } else { \ |
| GLfloat t = dpJ / (dpJ - dpI); \ |
| INTERP( ctx, t, O, J, I ); \ |
| I = O; \ |
| } \ |
| } \ |
| else if (NEGATIVE(dpI)) \ |
| return; \ |
| } \ |
| } while (0) |
| |
| |
| |
| /* Clip a line against the viewport and user clip planes. |
| */ |
| static void TAG(clip_draw_line)( GLcontext *ctx, |
| TNL_VERTEX *I, |
| TNL_VERTEX *J, |
| GLuint mask ) |
| { |
| LOCAL_VARS; |
| GET_INTERP_FUNC; |
| TNL_VERTEX tmp[MAX_CLIPPED_VERTICES]; |
| TNL_VERTEX *verts = tmp; |
| TNL_VERTEX *pv = J; |
| |
| LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
| LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
| LINE_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
| LINE_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
| LINE_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
| LINE_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
| |
| if ((ctx->_TriangleCaps & DD_FLATSHADE) && J != pv) |
| COPY_PV( ctx, J, pv ); |
| |
| DRAW_LINE( I, J ); |
| } |
| |
| |
| /* Clip a triangle against the viewport and user clip planes. |
| */ |
| static void TAG(clip_draw_triangle)( GLcontext *ctx, |
| TNL_VERTEX *v0, |
| TNL_VERTEX *v1, |
| TNL_VERTEX *v2, |
| GLuint mask ) |
| { |
| LOCAL_VARS; |
| GET_INTERP_FUNC; |
| TNL_VERTEX tmp[MAX_CLIPPED_VERTICES]; |
| TNL_VERTEX *verts = tmp; |
| TNL_VERTEX *(inlist[2][MAX_CLIPPED_VERTICES]); |
| TNL_VERTEX **out; |
| GLuint in = 0; |
| GLuint n = 3; |
| GLuint i; |
| |
| ASSIGN_3V(inlist, v2, v0, v1 ); /* pv rotated to slot zero */ |
| |
| POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
| POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
| POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
| POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
| POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
| POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
| |
| if ((ctx->_TriangleCaps & DD_FLATSHADE) && v2 != inlist[0]) |
| COPY_PV( ctx, inlist[0], v2 ); |
| |
| out = inlist[in]; |
| DRAW_POLYGON( out, n ); |
| } |
| |
| |
| static __inline void TAG(draw_triangle)( GLcontext *ctx, |
| TNL_VERTEX *v0, |
| TNL_VERTEX *v1, |
| TNL_VERTEX *v2 ) |
| { |
| LOCAL_VARS; |
| GLubyte ormask = (v0->mask | v1->mask | v2->mask); |
| |
| if ( !ormask ) { |
| DRAW_TRI( v0, v1, v2 ); |
| } else if ( !(v0->mask & v1->mask & v2->mask) ) { |
| TAG(clip_draw_triangle)( ctx, v0, v1, v2, ormask ); |
| } |
| } |
| |
| static __inline void TAG(draw_line)( GLcontext *ctx, |
| TNL_VERTEX *v0, |
| TNL_VERTEX *v1 ) |
| { |
| LOCAL_VARS; |
| GLubyte ormask = (v0->mask | v1->mask); |
| |
| if ( !ormask ) { |
| DRAW_LINE( v0, v1 ); |
| } else if ( !(v0->mask & v1->mask) ) { |
| TAG(clip_draw_line)( ctx, v0, v1, ormask ); |
| } |
| } |
| |
