From f51a32e82a907363a77d91b855e519f43191cad8 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Thu, 6 Apr 2006 22:07:01 +0000 Subject: [PATCH] Fix line clipping bug 6512. This fix is to discard the line if both dot products are negative. --- src/mesa/tnl/t_vb_cliptmp.h | 52 ++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 24 deletions(-) diff --git a/src/mesa/tnl/t_vb_cliptmp.h b/src/mesa/tnl/t_vb_cliptmp.h index ef034032f45..8d253c713e4 100644 --- a/src/mesa/tnl/t_vb_cliptmp.h +++ b/src/mesa/tnl/t_vb_cliptmp.h @@ -1,9 +1,8 @@ - /* * Mesa 3-D graphics library - * Version: 3.5 + * Version: 6.5.1 * - * Copyright (C) 1999-2001 Brian Paul All Rights Reserved. + * Copyright (C) 1999-2006 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"), @@ -29,9 +28,9 @@ #define CLIP_DOTPROD(K, A, B, C, D) X(K)*A + Y(K)*B + Z(K)*C + W(K)*D -#define POLY_CLIP( PLANE, A, B, C, D ) \ +#define POLY_CLIP( PLANE_BIT, A, B, C, D ) \ do { \ - if (mask & PLANE) { \ + if (mask & PLANE_BIT) { \ GLuint idxPrev = inlist[0]; \ GLfloat dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \ GLuint outcount = 0; \ @@ -81,29 +80,34 @@ do { \ } while (0) -#define LINE_CLIP(PLANE, A, B, C, D ) \ +#define LINE_CLIP(PLANE_BIT, A, B, C, D ) \ do { \ - if (mask & PLANE) { \ - GLfloat dp0 = CLIP_DOTPROD( v0, A, B, C, D ); \ - GLfloat dp1 = CLIP_DOTPROD( v1, A, B, C, D ); \ - \ - /* For regular clipping, we know from the clipmask that one of \ - * these must be negative (otherwise we wouldn't be here). For \ - * userclip, there is only a single bit for all active planes, \ - * so we can end up here when there is nothing to do, hence the \ - * second IS_NEGATIVE() test: \ + if (mask & PLANE_BIT) { \ + const GLfloat dp0 = CLIP_DOTPROD( v0, A, B, C, D ); \ + const GLfloat dp1 = CLIP_DOTPROD( v1, A, B, C, D ); \ + const GLboolean neg_dp0 = IS_NEGATIVE(dp0); \ + const GLboolean neg_dp1 = IS_NEGATIVE(dp1); \ + \ + /* For regular clipping, we know from the clipmask that one \ + * (or both) of these must be negative (otherwise we wouldn't \ + * be here). \ + * For userclip, there is only a single bit for all active \ + * planes, so we can end up here when there is nothing to do, \ + * hence the second IS_NEGATIVE() test: \ */ \ - if (IS_NEGATIVE(dp1)) { \ + if (neg_dp0 && neg_dp1) \ + return; /* both vertices outside clip plane: discard */ \ + \ + if (neg_dp1) { \ GLfloat t = dp1 / (dp1 - dp0); \ if (t > t1) t1 = t; \ - } else if (IS_NEGATIVE(dp0)) { \ + } else if (neg_dp0) { \ GLfloat t = dp0 / (dp0 - dp1); \ if (t > t0) t0 = t; \ } \ - \ if (t0 + t1 >= 1.0) \ - return; \ - } \ + return; /* discard */ \ + } \ } while (0) @@ -122,7 +126,6 @@ TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask ) GLfloat t1 = 0; GLuint p; - if (mask & 0x3f) { LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); @@ -133,7 +136,7 @@ TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask ) } if (mask & CLIP_USER_BIT) { - for (p=0;pConst.MaxClipPlanes; p++) { if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; @@ -161,6 +164,7 @@ TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask ) tnl->Driver.Render.CopyPV( ctx, newvert, v1 ); v1 = newvert; + newvert++; } else @@ -198,7 +202,7 @@ TAG(clip_tri)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask ) } if (mask & CLIP_USER_BIT) { - for (p=0;pConst.MaxClipPlanes; p++) { if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; @@ -249,7 +253,7 @@ TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3, } if (mask & CLIP_USER_BIT) { - for (p=0;pConst.MaxClipPlanes; p++) { if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; -- 2.30.2