i965: create code path to handle primitive restart in hardware

For newer hardware we disable the VBO module's software handling
of primitive restart. We now handle primitive restarts in
brw_handle_primitive_restart.

The initial version of brw_handle_primitive_restart simply calls
vbo_sw_primitive_restart, and therefore still uses the VBO
module software primitive restart support.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

docs/GL3.txt

@@ -46,7 +46,7 @@ GLSL 1.40                                             missing: UBOS, inverse(),
                                                       highp change
 Instanced drawing (GL_ARB_draw_instanced)             DONE (i965, gallium, swrast)
 Buffer copying (GL_ARB_copy_buffer)                   DONE (i965, r300, r600, swrast)
-Primitive restart (GL_NV_primitive_restart)           DONE (r600)
+Primitive restart (GL_NV_primitive_restart)           DONE (i965, r600)
 16 vertex texture image units                         DONE
 Texture buffer objs (GL_ARB_texture_buffer_object)    needs GL3.1 enabling (i965)
 Rectangular textures (GL_ARB_texture_rectangle)       DONE (i965, r300, r600, swrast)

src/mesa/drivers/dri/i965/Makefile.sources

@@ -55,6 +55,7 @@ i965_C_FILES = \
 	brw_misc_state.c \
 	brw_optimize.c \
 	brw_program.c \
+	brw_primitive_restart.c \
 	brw_queryobj.c \
 	brw_sf.c \
 	brw_sf_emit.c \

src/mesa/drivers/dri/i965/brw_context.c

@@ -296,6 +296,8 @@ brwCreateContext(int api,
       brw->has_negative_rhw_bug = true;
    }
 
+   brw->prim_restart.in_progress = false;
+
    brw_init_state( brw );
 
    brw->curbe.last_buf = calloc(1, 4096);

src/mesa/drivers/dri/i965/brw_context.h

@@ -1040,6 +1040,11 @@ struct brw_context
 
    uint32_t render_target_format[MESA_FORMAT_COUNT];
    bool format_supported_as_render_target[MESA_FORMAT_COUNT];
+
+   /* PrimitiveRestart */
+   struct {
+      bool in_progress;
+   } prim_restart;
 };
 
 

src/mesa/drivers/dri/i965/brw_draw.c

@@ -545,6 +545,12 @@ void brw_draw_prims( struct gl_context *ctx,
    if (!_mesa_check_conditional_render(ctx))
       return;
 
+   /* Handle primitive restart if needed */
+   if (brw_handle_primitive_restart(ctx, prim, nr_prims, ib)) {
+      /* The draw was handled, so we can exit now */
+      return;
+   }
+
    if (!vbo_all_varyings_in_vbos(arrays)) {
       if (!index_bounds_valid)
 	 vbo_get_minmax_indices(ctx, prim, ib, &min_index, &max_index, nr_prims);

src/mesa/drivers/dri/i965/brw_draw.h

@@ -51,4 +51,11 @@ void brw_draw_destroy( struct brw_context *brw );
 void brw_init_current_values(struct gl_context *ctx,
 			     struct gl_client_array *arrays);
 
+/* brw_primitive_restart.c */
+GLboolean
+brw_handle_primitive_restart(struct gl_context *ctx,
+                             const struct _mesa_prim *prim,
+                             GLuint nr_prims,
+                             const struct _mesa_index_buffer *ib);
+
 #endif

src/mesa/drivers/dri/i965/brw_primitive_restart.c

@@ -0,0 +1,87 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Jordan Justen <jordan.l.justen@intel.com>
+ *
+ */
+
+#include "main/imports.h"
+#include "main/bufferobj.h"
+
+#include "brw_context.h"
+#include "brw_draw.h"
+
+/**
+ * Check if primitive restart is enabled, and if so, handle it properly.
+ *
+ * In some cases the support will be handled in software. When available
+ * hardware will handle primitive restart.
+ */
+GLboolean
+brw_handle_primitive_restart(struct gl_context *ctx,
+                             const struct _mesa_prim *prim,
+                             GLuint nr_prims,
+                             const struct _mesa_index_buffer *ib)
+{
+   struct brw_context *brw = brw_context(ctx);
+
+   /* We only need to handle cases where there is an index buffer. */
+   if (ib == NULL) {
+      return GL_FALSE;
+   }
+
+   /* If the driver has requested software handling of primitive restarts,
+    * then the VBO module has already taken care of things, and we can
+    * just draw as normal.
+    */
+   if (ctx->Const.PrimitiveRestartInSoftware) {
+      return GL_FALSE;
+   }
+
+   /* If we have set the in_progress flag, then we are in the middle
+    * of handling the primitive restart draw.
+    */
+   if (brw->prim_restart.in_progress) {
+      return GL_FALSE;
+   }
+
+   /* If PrimitiveRestart is not enabled, then we aren't concerned about
+    * handling this draw.
+    */
+   if (!(ctx->Array.PrimitiveRestart)) {
+      return GL_FALSE;
+   }
+
+   /* Signal that we are in the process of handling the
+    * primitive restart draw
+    */
+   brw->prim_restart.in_progress = true;
+
+   vbo_sw_primitive_restart(ctx, prim, nr_prims, ib);
+
+   brw->prim_restart.in_progress = false;
+
+   /* The primitive restart draw was completed, so return true. */
+   return GL_TRUE;
+}
+

src/mesa/drivers/dri/intel/intel_extensions.c

@@ -168,4 +168,8 @@ intelInitExtensions(struct gl_context *ctx)
    else if (driQueryOptionb(&intel->optionCache, "force_s3tc_enable")) {
       ctx->Extensions.EXT_texture_compression_s3tc = true;
    }
+
+   if (intel->gen >= 4) {
+      ctx->Extensions.NV_primitive_restart = true;
+   }
 }