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authorBrian Paul <brian.paul@tungstengraphics.com>2006-04-06 22:07:01 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2006-04-06 22:07:01 +0000
commitf51a32e82a907363a77d91b855e519f43191cad8 (patch)
tree6545b591ddc4ce34ccf0f209c9ab35eb75418130
parent05529fefa498cf2967494feb19a03fb2a2cccd01 (diff)
Fix line clipping bug 6512.
This fix is to discard the line if both dot products are negative.
-rw-r--r--src/mesa/tnl/t_vb_cliptmp.h52
1 files changed, 28 insertions, 24 deletions
diff --git a/src/mesa/tnl/t_vb_cliptmp.h b/src/mesa/tnl/t_vb_cliptmp.h
index ef034032f4..8d253c713e 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;p<MAX_CLIP_PLANES;p++) {
+ for (p = 0; p < ctx->Const.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;p<MAX_CLIP_PLANES;p++) {
+ for (p = 0; p < ctx->Const.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;p<MAX_CLIP_PLANES;p++) {
+ for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
const GLfloat a = ctx->Transform._ClipUserPlane[p][0];
const GLfloat b = ctx->Transform._ClipUserPlane[p][1];