diff options
author | Brian <[email protected]> | 2007-07-10 15:24:31 -0600 |
---|---|---|
committer | Brian <[email protected]> | 2007-07-10 15:24:31 -0600 |
commit | a49a23efc5e320d8c9aa6f4f39be855632aa5cb8 (patch) | |
tree | bc5c08c77ef7f626b19039888b930a13e94bf77a /src/mesa/pipe/draw | |
parent | 985e37eedb9e91fce00a08e3ba961a052d8fa898 (diff) |
Fix line clipping bug. New comments.
Need to use a new prim_header for the post-clipped line. Otherwise,
we were changing the header passed to us from the vb code. That messed
up the vertex pointers for the next line primitive.
Diffstat (limited to 'src/mesa/pipe/draw')
-rw-r--r-- | src/mesa/pipe/draw/draw_clip.c | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/src/mesa/pipe/draw/draw_clip.c b/src/mesa/pipe/draw/draw_clip.c index 10a6c1b823c..a1c4cf01f05 100644 --- a/src/mesa/pipe/draw/draw_clip.c +++ b/src/mesa/pipe/draw/draw_clip.c @@ -69,7 +69,7 @@ static void interp_attr( GLfloat *fdst, /* Interpolate between two vertices to produce a third. */ -static void interp( struct clipper *clip, +static void interp( const struct clipper *clip, struct vertex_header *dst, GLfloat t, const struct vertex_header *out, @@ -98,9 +98,7 @@ static void interp( struct clipper *clip, const GLfloat *pos = dst->clip; const GLfloat *scale = clip->stage.draw->viewport.scale; const GLfloat *trans = clip->stage.draw->viewport.translate; - GLfloat oow; - - oow = 1.0 / pos[3]; + const GLfloat oow = 1.0 / pos[3]; dst->data[0][0] = pos[0] * oow * scale[0] + trans[0]; dst->data[0][1] = pos[1] * oow * scale[1] + trans[1]; @@ -110,6 +108,9 @@ static void interp( struct clipper *clip, /* Other attributes + * Note: start at 1 to skip winpos (data[0]) and subtract one + * since there's two vertex attrib slots we want to ignore (the header + * and the clippos. */ for (j = 1; j < nr_attrs-1; j++) { interp_attr(dst->data[j], t, in->data[j], out->data[j]); @@ -295,13 +296,14 @@ do_clip_line( struct prim_stage *stage, struct prim_header *header, GLuint clipmask ) { - struct clipper *clipper = clipper_stage( stage ); + const struct clipper *clipper = clipper_stage( stage ); struct vertex_header *v0 = header->v[0]; struct vertex_header *v1 = header->v[1]; const GLfloat *pos0 = v0->clip; const GLfloat *pos1 = v1->clip; GLfloat t0 = 0; GLfloat t1 = 0; + struct prim_header newprim; /* XXX: Note stupid hack to deal with tnl's 8-bit clipmask. Remove * this once we correctly use 16bit masks for userclip planes. @@ -313,43 +315,47 @@ do_clip_line( struct prim_stage *stage, } while (clipmask) { - GLuint plane_idx = ffs(clipmask)-1; + const GLuint plane_idx = ffs(clipmask)-1; const GLfloat *plane = clipper->plane[plane_idx]; - - clipmask &= ~(1<<plane_idx); - const GLfloat dp0 = dot4( pos0, plane ); const GLfloat dp1 = dot4( pos1, plane ); if (dp1 < 0) { GLfloat t = dp1 / (dp1 - dp0); - if (t > t1) t1 = t; + t1 = MIN2(t1, t); } if (dp0 < 0) { GLfloat t = dp0 / (dp0 - dp1); - if (t > t0) t0 = t; + t0 = MIN2(t0, t); } if (t0 + t1 >= 1.0) return; /* discard */ + + clipmask &= ~(1 << plane_idx); /* turn off this plane's bit */ } if (v0->clipmask) { interp( clipper, stage->tmp[0], t0, v0, v1 ); - header->v[0] = stage->tmp[0]; + newprim.v[0] = stage->tmp[0]; + } + else { + newprim.v[0] = v0; } if (v1->clipmask) { interp( clipper, stage->tmp[1], t1, v1, v0 ); - header->v[1] = stage->tmp[1]; + newprim.v[1] = stage->tmp[1]; + } + else { + newprim.v[1] = v1; } - stage->next->line( stage->next, header ); + stage->next->line( stage->next, &newprim ); } - static void clip_begin( struct prim_stage *stage ) { struct clipper *clipper = clipper_stage(stage); @@ -361,7 +367,8 @@ static void clip_begin( struct prim_stage *stage ) stage->next->begin( stage->next ); } - + + static void clip_point( struct prim_stage *stage, struct prim_header *header ) |