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authorCorbin Simpson <[email protected]>2009-12-18 19:42:02 -0800
committerCorbin Simpson <[email protected]>2009-12-18 19:49:14 -0800
commitf13a904c34cf7ac5aae3d50a1421259895fc9a08 (patch)
tree8cef153cda764a8a89d610c6c56fabfc9d56b376 /src/gallium/drivers/r300/r300_render.c
parentbf611cef29d664c2c2b56d2175c3a966c720e8b8 (diff)
r300g: Respect provoking vertex for trifans.
Fixes part of piglit's clipFlat test; next up is to get quads right.
Diffstat (limited to 'src/gallium/drivers/r300/r300_render.c')
-rw-r--r--src/gallium/drivers/r300/r300_render.c33
1 files changed, 31 insertions, 2 deletions
diff --git a/src/gallium/drivers/r300/r300_render.c b/src/gallium/drivers/r300/r300_render.c
index a0d67e76181..11c7ce859db 100644
--- a/src/gallium/drivers/r300/r300_render.c
+++ b/src/gallium/drivers/r300/r300_render.c
@@ -75,13 +75,40 @@ static boolean r300_nothing_to_draw(struct r300_context *r300)
r300->scissor_state->scissor.empty_area;
}
+static uint32_t r300_provoking_vertex_fixes(struct r300_context *r300,
+ unsigned mode)
+{
+ uint32_t color_control = r300->rs_state->color_control;
+
+ /* By default (see r300_state.c:r300_create_rs_state) color_control is
+ * initialized to provoking the first vertex.
+ *
+ * If we are provoking the first vertex, then there's a quirk in the
+ * specification for ARB_provoking_vertex that essentially makes the
+ * second vertex the correct one to provoke for triangle fans.
+ * (http://www.opengl.org/registry/specs/ARB/provoking_vertex.txt)
+ * Otherwise, force the last vertex, as GL standard. */
+
+ if (r300->rs_state->rs.flatshade_first) {
+ if (mode == PIPE_PRIM_TRIANGLE_FAN) {
+ color_control |= R300_GA_COLOR_CONTROL_PROVOKING_VERTEX_SECOND;
+ }
+ } else {
+ color_control |= R300_GA_COLOR_CONTROL_PROVOKING_VERTEX_LAST;
+ }
+
+ return color_control;
+}
+
static void r300_emit_draw_arrays(struct r300_context *r300,
unsigned mode,
unsigned count)
{
CS_LOCALS(r300);
- BEGIN_CS(6);
+ BEGIN_CS(8);
+ OUT_CS_REG(R300_GA_COLOR_CONTROL,
+ r300_provoking_vertex_fixes(r300, mode));
OUT_CS_REG(R300_VAP_VF_MIN_VTX_INDX, 0);
OUT_CS_REG(R300_VAP_VF_MAX_VTX_INDX, count - 1);
OUT_CS_PKT3(R300_PACKET3_3D_DRAW_VBUF_2, 0);
@@ -108,7 +135,9 @@ static void r300_emit_draw_elements(struct r300_context *r300,
assert((start * indexSize) % 4 == 0);
assert(offset_dwords == 0);
- BEGIN_CS(12);
+ BEGIN_CS(14);
+ OUT_CS_REG(R300_GA_COLOR_CONTROL,
+ r300_provoking_vertex_fixes(r300, mode));
OUT_CS_REG(R300_VAP_VF_MIN_VTX_INDX, minIndex);
OUT_CS_REG(R300_VAP_VF_MAX_VTX_INDX, maxIndex);
OUT_CS_PKT3(R300_PACKET3_3D_DRAW_INDX_2, 0);