[Glamor] [PATCH] Fix a bug for trapezoid clip
junyan.he at linux.intel.com
junyan.he at linux.intel.com
Thu Jun 14 18:00:15 PDT 2012
From: Junyan He <junyan.he at linux.intel.com>
We find in some cases the trapezoid will be render as a triangle and
the left edge and right edge will cross with each other just bellow
the top or over the bottom. The distance between the cross poind and
the top or bottom is less than pixman_fixed_1_minus_e, so after the
fixed converted to int, the cross point has the same value with the
top or botton and the triangle should not be affected. But in our
clip logic, the cross point will be clipped out. So add a logic
to fix this problem.
Signed-off-by: Junyan He <junyan.he at linux.intel.com>
---
src/glamor_priv.h | 2 +-
src/glamor_trapezoid.c | 115 ++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 108 insertions(+), 9 deletions(-)
diff --git a/src/glamor_priv.h b/src/glamor_priv.h
index 1b45a71..055077c 100644
--- a/src/glamor_priv.h
+++ b/src/glamor_priv.h
@@ -965,7 +965,7 @@ glamor_poly_line(DrawablePtr pDrawable, GCPtr pGC, int mode, int npt,
#define GLAMOR_PIXMAP_DYNAMIC_UPLOAD
#ifndef GLAMOR_GLES2
#define GLAMOR_GRADIENT_SHADER
-#define GLAMOR_TRAPEZOID_SHADER
+//#define GLAMOR_TRAPEZOID_SHADER
#endif
#define GLAMOR_TEXTURED_LARGE_PIXMAP 1
#if 0
diff --git a/src/glamor_trapezoid.c b/src/glamor_trapezoid.c
index cc6a706..6f85769 100644
--- a/src/glamor_trapezoid.c
+++ b/src/glamor_trapezoid.c
@@ -38,6 +38,8 @@
#ifdef GLAMOR_TRAPEZOID_SHADER
+#define DEBUG_CLIP_VTX 0
+
#define POINT_INSIDE_CLIP_RECT(point, rect) \
(point[0] >= IntToxFixed(rect->x1) \
&& point[0] <= IntToxFixed(rect->x2) \
@@ -45,6 +47,28 @@
&& point[1] <= IntToxFixed(rect->y2))
static xFixed
+_glamor_lines_crossfixedY (xLineFixed *l, xLineFixed *r)
+{
+ xFixed dx1 = l->p2.x - l->p1.x;
+ xFixed dx2 = r->p2.x - r->p1.x;
+ xFixed dy1 = l->p2.y - l->p1.y;
+ xFixed dy2 = r->p2.y - r->p1.y;
+ xFixed_32_32 tmp = (xFixed_32_32) dy2 * dy1;
+ xFixed_32_32 dividend1 = (tmp >> 32) * (l->p1.x - r->p1.x);
+ tmp = (xFixed_32_32) dx1 * dy2;
+ xFixed_32_32 dividend2 = (tmp >> 32) * l->p1.y;
+ tmp = (xFixed_32_32) dy1 * dx2;
+ xFixed_32_32 dividend3 = (tmp >> 32) * r->p1.y;
+ xFixed_32_32 divisor = ((xFixed_32_32) dx1 * (xFixed_32_32) dy2
+ - (xFixed_32_32) dy1 * (xFixed_32_32) dx2) >> 32;
+
+ if (divisor)
+ return (xFixed)((dividend2 - dividend1 - dividend3) / divisor);
+
+ return 0xFFFFFFFF;
+}
+
+static xFixed
_glamor_linefixedX (xLineFixed *l, xFixed y, Bool ceil)
{
xFixed dx = l->p2.x - l->p1.x;
@@ -67,22 +91,86 @@ _glamor_linefixedY (xLineFixed *l, xFixed x, Bool ceil)
}
static Bool
-point_inside_trapezoid(int point[2], xTrapezoid * trap)
+point_inside_trapezoid(int point[2], xTrapezoid * trap, xFixed cut_y)
{
int ret = TRUE;
int tmp;
- if (point[1] > trap->bottom
- || point[1] < trap->top)
+ if (point[1] > trap->bottom) {
+ ret = FALSE;
+ if (DEBUG_CLIP_VTX) {
+ ErrorF("Out of Trap bottom, point[1] = %d(0x%x)), "
+ "bottom = %d(0x%x)\n",
+ (unsigned int)xFixedToInt(point[1]), point[1],
+ (unsigned int)xFixedToInt(trap->bottom),
+ (unsigned int)trap->bottom);
+ }
+
+ return ret;
+ }
+
+ if (point[1] < trap->top) {
ret = FALSE;
+ if (DEBUG_CLIP_VTX) {
+ ErrorF("Out of Trap top, point[1] = %d(0x%x)), "
+ "top = %d(0x%x)\n",
+ (unsigned int)xFixedToInt(point[1]), point[1],
+ (unsigned int)xFixedToInt(trap->top),
+ (unsigned int)trap->top);
+ }
+
+ return ret;
+ }
tmp = _glamor_linefixedX (&trap->left, point[1], FALSE);
- if (point[0] < tmp)
+ if (point[0] < tmp) {
ret = FALSE;
+
+ if (abs(cut_y - trap->top) < pixman_fixed_1_minus_e &&
+ abs(point[1] - trap->top) < pixman_fixed_1_minus_e &&
+ tmp - point[0] < pixman_fixed_1_minus_e) {
+ ret = TRUE;
+ } else if (abs(cut_y - trap->bottom) < pixman_fixed_1_minus_e &&
+ point[1] - trap->bottom < pixman_fixed_1_minus_e &&
+ tmp - point[0] < pixman_fixed_1_minus_e) {
+ ret = TRUE;
+ }
+
+ if (DEBUG_CLIP_VTX && !ret) {
+ ErrorF("Out of Trap left, point[0] = %d(0x%x)), "
+ "left = %d(0x%x)\n",
+ (unsigned int)xFixedToInt(point[0]), point[0],
+ (unsigned int)xFixedToInt(tmp), (unsigned int)tmp);
+ }
+
+ if (!ret)
+ return ret;
+ }
tmp = _glamor_linefixedX (&trap->right, point[1], TRUE);
- if (point[0] > tmp)
+ if (point[0] > tmp) {
ret = FALSE;
+ if (abs(cut_y - trap->top) < pixman_fixed_1_minus_e &&
+ abs(point[1] - trap->top) < pixman_fixed_1_minus_e &&
+ point[0] - tmp < pixman_fixed_1_minus_e) {
+ ret = TRUE;
+ } else if (abs(cut_y - trap->bottom) < pixman_fixed_1_minus_e &&
+ abs(point[1] - trap->bottom) < pixman_fixed_1_minus_e &&
+ point[0] - tmp < pixman_fixed_1_minus_e) {
+ ret = TRUE;
+ }
+
+ if (DEBUG_CLIP_VTX && !ret) {
+ ErrorF("Out of Trap right, point[0] = %d(0x%x)), "
+ "right = %d(0x%x)\n",
+ (unsigned int)xFixedToInt(point[0]), point[0],
+ (unsigned int)xFixedToInt(tmp), (unsigned int)tmp);
+ }
+
+ if (!ret)
+ return ret;
+ }
+
return ret;
}
@@ -125,12 +213,11 @@ glamor_flush_composite_triangles(ScreenPtr screen)
glamor_put_dispatch(glamor_priv);
}
-#define DEBUG_CLIP_VTX 0
-
static Bool
_glamor_clip_trapezoid_vertex(xTrapezoid * trap, BoxPtr pbox,
int vertex[6], int *num)
{
+ xFixed edge_cross_y = 0xFFFFFFFF;
int tl[2];
int bl[2];
int tr[2];
@@ -217,7 +304,7 @@ _glamor_clip_trapezoid_vertex(xTrapezoid * trap, BoxPtr pbox,
#define ADD_VERTEX_IF_INSIDE(vtx) \
if(POINT_INSIDE_CLIP_RECT(vtx, pbox) \
- && point_inside_trapezoid(vtx, trap)){ \
+ && point_inside_trapezoid(vtx, trap, edge_cross_y)){ \
tmp_vtx[vertex_num] = xFixedToInt(vtx[0]); \
tmp_vtx[vertex_num + 1] = xFixedToInt(vtx[1]); \
vertex_num += 2; \
@@ -239,6 +326,18 @@ _glamor_clip_trapezoid_vertex(xTrapezoid * trap, BoxPtr pbox,
"the Rect\n"); \
}
+ /*Trap's right edge cut right edge. */
+ if((!IS_TRAP_EDGE_VERTICAL((&trap->left))) ||
+ (!IS_TRAP_EDGE_VERTICAL((&trap->right)))) {
+ edge_cross_y = _glamor_lines_crossfixedY((&trap->left), (&trap->right));
+ if (DEBUG_CLIP_VTX) {
+ ErrorF("Trap's left edge cut right edge at %d(0x%x), "
+ "trap_top = %x, trap_bottom = %x\n",
+ xFixedToInt(edge_cross_y), edge_cross_y,
+ (unsigned int)trap->top, (unsigned int)trap->bottom);
+ }
+ }
+
/*Trap's TopLeft, BottomLeft, TopRight and BottomRight. */
CACULATE_CUT_VERTEX(tl, 1, FALSE, trap->top, (&trap->left));
CACULATE_CUT_VERTEX(bl, 1, FALSE, trap->bottom, (&trap->left));
--
1.7.7.6
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