summaryrefslogtreecommitdiff
path: root/src/mesa/tnl/t_vb_cliptmp.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/mesa/tnl/t_vb_cliptmp.h')
-rw-r--r--src/mesa/tnl/t_vb_cliptmp.h103
1 files changed, 88 insertions, 15 deletions
diff --git a/src/mesa/tnl/t_vb_cliptmp.h b/src/mesa/tnl/t_vb_cliptmp.h
index 618b8b3130..0d2183a9e6 100644
--- a/src/mesa/tnl/t_vb_cliptmp.h
+++ b/src/mesa/tnl/t_vb_cliptmp.h
@@ -80,6 +80,58 @@ do { \
} while (0)
+#define POLY_USERCLIP(PLANE) \
+do { \
+ if (mask & CLIP_USER_BIT) { \
+ GLuint idxPrev = inlist[0]; \
+ GLfloat dpPrev = VB->ClipDistancePtr[PLANE][idxPrev]; \
+ GLuint outcount = 0; \
+ GLuint i; \
+ \
+ inlist[n] = inlist[0]; /* prevent rotation of vertices */ \
+ for (i = 1; i <= n; i++) { \
+ GLuint idx = inlist[i]; \
+ GLfloat dp = VB->ClipDistancePtr[PLANE][idx]; \
+ \
+ if (!IS_NEGATIVE(dpPrev)) { \
+ outlist[outcount++] = idxPrev; \
+ } \
+ \
+ if (DIFFERENT_SIGNS(dp, dpPrev)) { \
+ if (IS_NEGATIVE(dp)) { \
+ /* Going out of bounds. Avoid division by zero as we \
+ * know dp != dpPrev from DIFFERENT_SIGNS, above. \
+ */ \
+ GLfloat t = dp / (dp - dpPrev); \
+ INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \
+ interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \
+ } else { \
+ /* Coming back in. \
+ */ \
+ GLfloat t = dpPrev / (dpPrev - dp); \
+ INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \
+ interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \
+ } \
+ outlist[outcount++] = newvert++; \
+ } \
+ \
+ idxPrev = idx; \
+ dpPrev = dp; \
+ } \
+ \
+ if (outcount < 3) \
+ return; \
+ \
+ { \
+ GLuint *tmp = inlist; \
+ inlist = outlist; \
+ outlist = tmp; \
+ n = outcount; \
+ } \
+ } \
+} while (0)
+
+
#define LINE_CLIP(PLANE_BIT, A, B, C, D ) \
do { \
if (mask & PLANE_BIT) { \
@@ -111,6 +163,37 @@ do { \
} while (0)
+#define LINE_USERCLIP(PLANE) \
+do { \
+ if (mask & CLIP_USER_BIT) { \
+ const GLfloat dp0 = VB->ClipDistancePtr[PLANE][v0]; \
+ const GLfloat dp1 = VB->ClipDistancePtr[PLANE][v1]; \
+ 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 (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 (neg_dp0) { \
+ GLfloat t = dp0 / (dp0 - dp1); \
+ if (t > t0) t0 = t; \
+ } \
+ if (t0 + t1 >= 1.0) \
+ return; /* discard */ \
+ } \
+} while (0)
+
+
/* Clip a line against the viewport and user clip planes.
*/
@@ -139,11 +222,7 @@ TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask )
if (mask & CLIP_USER_BIT) {
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];
- const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
- const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
- LINE_CLIP( CLIP_USER_BIT, a, b, c, d );
+ LINE_USERCLIP(p);
}
}
}
@@ -228,11 +307,7 @@ TAG(clip_tri)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask )
if (mask & CLIP_USER_BIT) {
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];
- const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
- const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
- POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
+ POLY_USERCLIP(p);
}
}
}
@@ -291,11 +366,7 @@ TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3,
if (mask & CLIP_USER_BIT) {
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];
- const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
- const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
- POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
+ POLY_USERCLIP(p);
}
}
}
@@ -317,4 +388,6 @@ TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3,
#undef SIZE
#undef TAG
#undef POLY_CLIP
+#undef POLY_USERCLIP
#undef LINE_CLIP
+#undef LINE_USERCLIP