r600: add occlusion query support

Based on initial patch from Stephan Schmid <stephan_2303@gmx.de>.

Basic idea is to dump the zpass count at the start and end of the query
and subtract to get the total number of visible fragments.  HW writes
alternating qwords for up to 4 DBs.  On the first pass, we start at
buffer address + 0; on the second pass, we start at buffer address + 8
(bytes). The resulting buffer at the end of the query looks like:

qw[0]: db0 start
qw[1]: db0 end
...
qw[6]: db3 start
qw[7]: db3 end

The MSB of each qword is the valid bit and the lower 63 bits are
the zpass count for that DB.

OQ on RV740 is disabled at the moment as it only seems to report
results for half of its DBs.  This needs further investigation.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>

1 files changed, 27 insertions, 4 deletions

diff --git a/src/mesa/drivers/dri/r600/r600_context.c b/src/mesa/drivers/dri/r600/r600_context.c
index c1bf76deb8..6de151d51b 100644
--- a/src/mesa/drivers/dri/r600/r600_context.c
+++ b/src/mesa/drivers/dri/r600/r600_context.c
@@ -64,6 +64,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include "r600_cmdbuf.h"
 #include "r600_emit.h"
 #include "radeon_bocs_wrapper.h"
+#include "radeon_queryobj.h"
 
 #include "r700_state.h"
 #include "r700_ioctl.h"
@@ -73,11 +74,8 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include "utils.h"
 #include "xmlpool.h"		/* for symbolic values of enum-type options */
 
-/* hw_tcl_on derives from future_hw_tcl_on when its safe to change it. */
-int future_hw_tcl_on = 1;
-int hw_tcl_on = 1;
-
 #define need_GL_VERSION_2_0
+#define need_GL_ARB_occlusion_query
 #define need_GL_ARB_point_parameters
 #define need_GL_ARB_vertex_program
 #define need_GL_EXT_blend_equation_separate
@@ -98,6 +96,7 @@ static const struct dri_extension card_extensions[] = {
   /* *INDENT-OFF* */
   {"GL_ARB_depth_texture",		NULL},
   {"GL_ARB_fragment_program",		NULL},
+  {"GL_ARB_occlusion_query",            GL_ARB_occlusion_query_functions},
   {"GL_ARB_multitexture",		NULL},
   {"GL_ARB_point_parameters",		GL_ARB_point_parameters_functions},
   {"GL_ARB_shadow",			NULL},
@@ -204,6 +203,24 @@ static void r600_fallback(GLcontext *ctx, GLuint bit, GLboolean mode)
 		context->radeon.Fallback &= ~bit;
 }
 
+static void r600_emit_query_finish(radeonContextPtr radeon)
+{
+	context_t *context = (context_t*) radeon;
+	BATCH_LOCALS(&context->radeon);
+
+	struct radeon_query_object *query = radeon->query.current;
+
+	BEGIN_BATCH_NO_AUTOSTATE(4 + 2);
+	R600_OUT_BATCH(CP_PACKET3(R600_IT_EVENT_WRITE, 2));
+	R600_OUT_BATCH(ZPASS_DONE);
+	R600_OUT_BATCH(query->curr_offset + 8); /* hw writes qwords */
+	R600_OUT_BATCH(0x00000000);
+	R600_OUT_BATCH_RELOC(VGT_EVENT_INITIATOR, query->bo, 0, 0, RADEON_GEM_DOMAIN_GTT, 0);
+	END_BATCH();
+	assert(query->curr_offset < RADEON_QUERY_PAGE_SIZE);
+	query->emitted_begin = GL_FALSE;
+}
+
 static void r600_init_vtbl(radeonContextPtr radeon)
 {
 	radeon->vtbl.get_lock = r600_get_lock;
@@ -212,6 +229,7 @@ static void r600_init_vtbl(radeonContextPtr radeon)
 	radeon->vtbl.swtcl_flush = NULL;
 	radeon->vtbl.pre_emit_atoms = r600_vtbl_pre_emit_atoms;
 	radeon->vtbl.fallback = r600_fallback;
+	radeon->vtbl.emit_query_finish = r600_emit_query_finish;
 }
 
 static void r600InitConstValues(GLcontext *ctx, radeonScreenPtr screen)
@@ -302,6 +320,10 @@ static void r600InitGLExtensions(GLcontext *ctx)
 	{
 		_mesa_enable_extension(ctx, "GL_EXT_texture_compression_s3tc");
 	}
+
+	/* XXX: RV740 only seems to report results from half of its DBs */
+	if (r600->radeon.radeonScreen->chip_family == CHIP_FAMILY_RV740)
+		_mesa_disable_extension(ctx, "GL_ARB_occlusion_query");
 }
 
 /* Create the device specific rendering context.
@@ -340,6 +362,7 @@ GLboolean r600CreateContext(const __GLcontextModes * glVisual,
 	r700InitStateFuncs(&functions);
 	r600InitTextureFuncs(&functions);
 	r700InitShaderFuncs(&functions);
+	radeonInitQueryObjFunctions(&functions);
 	r700InitIoctlFuncs(&functions);
 	radeonInitBufferObjectFuncs(&functions);