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-rw-r--r--src/gallium/drivers/llvmpipe/lp_setup_tri.c79
1 files changed, 39 insertions, 40 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
index eeffbb5fee..0d57f13f61 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -228,7 +228,6 @@ do_triangle_ccw(struct lp_setup_context *setup,
struct lp_rast_triangle *tri;
int x[3];
int y[3];
- int area;
struct u_rect bbox;
unsigned tri_bytes;
int i;
@@ -312,21 +311,8 @@ do_triangle_ccw(struct lp_setup_context *setup,
tri->plane[1].dcdx = y[1] - y[2];
tri->plane[2].dcdx = y[2] - y[0];
- area = (tri->plane[0].dcdy * tri->plane[2].dcdx -
- tri->plane[2].dcdy * tri->plane[0].dcdx);
-
LP_COUNT(nr_tris);
- /* Cull non-ccw and zero-sized triangles.
- *
- * XXX: subject to overflow??
- */
- if (area <= 0) {
- lp_scene_putback_data( scene, tri_bytes );
- LP_COUNT(nr_culled_tris);
- return TRUE;
- }
-
/* Setup parameter interpolants:
*/
lp_setup_tri_coef( setup, &tri->inputs, v0, v1, v2, frontfacing );
@@ -635,23 +621,36 @@ fail:
/**
- * Draw triangle if it's CW, cull otherwise.
+ * Try to draw the triangle, restart the scene on failure.
*/
-static void triangle_cw( struct lp_setup_context *setup,
- const float (*v0)[4],
- const float (*v1)[4],
- const float (*v2)[4] )
+static void retry_triangle_ccw( struct lp_setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4],
+ boolean front)
{
- if (!do_triangle_ccw( setup, v1, v0, v2, !setup->ccw_is_frontface ))
+ if (!do_triangle_ccw( setup, v0, v1, v2, front ))
{
if (!lp_setup_flush_and_restart(setup))
return;
- if (!do_triangle_ccw( setup, v1, v0, v2, !setup->ccw_is_frontface ))
+ if (!do_triangle_ccw( setup, v0, v1, v2, front ))
return;
}
}
+static INLINE float
+calc_area(const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4])
+{
+ float dx01 = v0[0][0] - v1[0][0];
+ float dy01 = v0[0][1] - v1[0][1];
+ float dx20 = v2[0][0] - v0[0][0];
+ float dy20 = v2[0][1] - v0[0][1];
+ return dx01 * dy20 - dx20 * dy01;
+}
+
/**
* Draw triangle if it's CW, cull otherwise.
@@ -661,17 +660,23 @@ static void triangle_cw( struct lp_setup_context *setup,
const float (*v1)[4],
const float (*v2)[4] )
{
- if (!do_triangle_ccw( setup, v0, v1, v2, setup->ccw_is_frontface ))
- {
- if (!lp_setup_flush_and_restart(setup))
- return;
+ float area = calc_area(v0, v1, v2);
- if (!do_triangle_ccw( setup, v0, v1, v2, setup->ccw_is_frontface ))
- return;
- }
+ if (area < 0.0f)
+ retry_triangle_ccw(setup, v0, v2, v1, !setup->ccw_is_frontface);
}
+static void triangle_ccw( struct lp_setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4])
+{
+ float area = calc_area(v0, v1, v2);
+
+ if (area > 0.0f)
+ retry_triangle_ccw(setup, v0, v1, v2, setup->ccw_is_frontface);
+}
/**
* Draw triangle whether it's CW or CCW.
@@ -681,18 +686,12 @@ static void triangle_both( struct lp_setup_context *setup,
const float (*v1)[4],
const float (*v2)[4] )
{
- /* edge vectors e = v0 - v2, f = v1 - v2 */
- const float ex = v0[0][0] - v2[0][0];
- const float ey = v0[0][1] - v2[0][1];
- const float fx = v1[0][0] - v2[0][0];
- const float fy = v1[0][1] - v2[0][1];
-
- /* det = cross(e,f).z */
- const float det = ex * fy - ey * fx;
- if (det < 0.0f)
- triangle_ccw( setup, v0, v1, v2 );
- else if (det > 0.0f)
- triangle_cw( setup, v0, v1, v2 );
+ float area = calc_area(v0, v1, v2);
+
+ if (area > 0.0f)
+ retry_triangle_ccw( setup, v0, v1, v2, setup->ccw_is_frontface );
+ else if (area < 0.0f)
+ retry_triangle_ccw( setup, v0, v2, v1, !setup->ccw_is_frontface );
}