svga: add new svga_state_tgsi_transform.c file

Signed-off-by: Brian Paul <brianp@vmware.com>

src/gallium/drivers/svga/svga_state_tgsi_transform.c

@@ -0,0 +1,293 @@
+/**********************************************************
+ * Copyright 2014 VMware, Inc.  All rights reserved.
+ *
+ * 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 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.
+ *
+ **********************************************************/
+
+#include "util/u_inlines.h"
+#include "util/u_memory.h"
+#include "util/u_bitmask.h"
+#include "util/u_simple_shaders.h"
+#include "tgsi/tgsi_ureg.h"
+#include "tgsi/tgsi_point_sprite.h"
+#include "tgsi/tgsi_dump.h"
+
+#include "svga_context.h"
+#include "svga_shader.h"
+#include "svga_tgsi.h"
+
+
+/**
+ * Bind a new GS.  This updates the derived current gs state, not the
+ * user-specified GS state.
+ */
+static void
+bind_gs_state(struct svga_context *svga,
+              struct svga_geometry_shader *gs)
+{
+   svga->curr.gs = gs;
+   svga->dirty |= SVGA_NEW_GS;
+}
+
+
+/**
+ * emulate_point_sprite searches the shader variants list to see it there is
+ * a shader variant with a token string that matches the emulation
+ * requirement. It there isn't, then it will use a tgsi utility
+ * tgsi_add_point_sprite to transform the original token string to support
+ * point sprite. A new geometry shader state will be created with the
+ * transformed token string and added to the shader variants list of the
+ * original geometry shader. The new geometry shader state will then be
+ * bound as the current geometry shader.
+ */
+static struct svga_shader *
+emulate_point_sprite(struct svga_context *svga,
+                     struct svga_shader *shader,
+                     const struct tgsi_token *tokens)
+{
+   struct svga_token_key key;
+   struct tgsi_token *new_tokens;
+   const struct tgsi_token *orig_tokens;
+   struct svga_geometry_shader *orig_gs = (struct svga_geometry_shader *)shader;
+   struct svga_geometry_shader *gs = NULL;
+   struct pipe_shader_state templ;
+   struct svga_stream_output *streamout = NULL;
+   int pos_out_index = -1;
+   int aa_point_coord_index = -1;
+
+   assert(tokens != NULL);
+
+   orig_tokens = tokens;
+
+   /* Create a token key */
+   memset(&key, 0, sizeof key);
+   key.gs.writes_psize = 1;
+   key.gs.sprite_coord_enable = svga->curr.rast->templ.sprite_coord_enable;
+
+   key.gs.sprite_origin_upper_left =
+      !(svga->curr.rast->templ.sprite_coord_mode == PIPE_SPRITE_COORD_LOWER_LEFT);
+
+   key.gs.aa_point = svga->curr.rast->templ.point_smooth;
+
+   if (orig_gs != NULL) {
+
+      /* Check if the original geometry shader has stream output and
+       * if position is one of the outputs.
+       */
+      streamout = orig_gs->base.stream_output;
+      if (streamout != NULL) {
+         pos_out_index = streamout->pos_out_index;
+         key.gs.point_pos_stream_out = pos_out_index != -1;
+      }
+
+      /* Search the shader lists to see if there is a variant that matches
+       * this token key.
+       */
+      gs = (struct svga_geometry_shader *)
+              svga_search_shader_token_key(&orig_gs->base, &key);
+   }
+
+   /* If there isn't, then call the tgsi utility tgsi_add_point_sprite
+    * to transform the original tokens to support point sprite.
+    * Flip the sprite origin as SVGA3D device only supports an
+    * upper-left origin.
+    */
+   if (!gs) {
+      new_tokens = tgsi_add_point_sprite(orig_tokens,
+                                         key.gs.sprite_coord_enable,
+                                         key.gs.sprite_origin_upper_left,
+                                         key.gs.point_pos_stream_out,
+                                         key.gs.aa_point ?
+                                            &aa_point_coord_index : NULL);
+
+      if (new_tokens == NULL) {
+         /* if no new tokens are generated for whatever reason, just return */
+         return NULL;
+      }
+
+      if (0) {
+         debug_printf("Before tgsi_add_point_sprite ---------------\n");
+         tgsi_dump(orig_tokens, 0);
+         debug_printf("After tgsi_add_point_sprite --------------\n");
+         tgsi_dump(new_tokens, 0);
+      }
+
+      templ.tokens = new_tokens;
+      templ.stream_output.num_outputs = 0;
+
+      if (streamout != NULL) {
+         templ.stream_output = streamout->info;
+         /* The tgsi_add_point_sprite utility adds an extra output
+          * for the original point position for stream output purpose.
+          * We need to replace the position output register index in the
+          * stream output declaration with the new register index.
+          */
+         if (pos_out_index != -1) {
+            assert(orig_gs != NULL);
+            templ.stream_output.output[pos_out_index].register_index =
+               orig_gs->base.info.num_outputs;
+         }
+      }
+
+      /* Create a new geometry shader state with the new tokens */
+      gs = svga->pipe.create_gs_state(&svga->pipe, &templ);
+
+      /* Don't need the token string anymore. There is a local copy
+       * in the shader state.
+       */
+      FREE(new_tokens);
+
+      if (!gs) {
+         return NULL;
+      }
+
+      gs->wide_point = TRUE;
+      gs->aa_point_coord_index = aa_point_coord_index;
+      gs->base.token_key = key;
+      gs->base.parent = &orig_gs->base;
+      gs->base.next = NULL;
+
+      /* Add the new geometry shader to the head of the shader list
+       * pointed to by the original geometry shader.
+       */
+      if (orig_gs != NULL) {
+         gs->base.next = orig_gs->base.next;
+         orig_gs->base.next = &gs->base;
+      }
+   }
+
+   /* Bind the new geometry shader state */
+   bind_gs_state(svga, gs);
+
+   return &gs->base;
+}
+
+/**
+ * Generate a geometry shader that emits a wide point by drawing a quad.
+ * This function first creates a passthrough geometry shader and then
+ * calls emulate_point_sprite() to transform the geometry shader to
+ * support point sprite.
+ */
+static struct svga_shader *
+add_point_sprite_shader(struct svga_context *svga)
+{
+   struct svga_vertex_shader *vs = svga->curr.vs;
+   struct svga_geometry_shader *orig_gs = vs->gs;
+   struct svga_geometry_shader *new_gs;
+   const struct tgsi_token *tokens;
+
+   if (orig_gs == NULL) {
+
+      /* If this is the first time adding a geometry shader to this
+       * vertex shader to support point sprite, then create
+       * a passthrough geometry shader first.
+       */
+      orig_gs = (struct svga_geometry_shader *)
+                   util_make_geometry_passthrough_shader(
+                      &svga->pipe, vs->base.info.num_outputs,
+                      vs->base.info.output_semantic_name,
+                      vs->base.info.output_semantic_index);
+
+      if (orig_gs == NULL)
+         return NULL;
+   }
+   else {
+      if (orig_gs->base.parent)
+         orig_gs = (struct svga_geometry_shader *)orig_gs->base.parent;
+   }
+   tokens = orig_gs->base.tokens;
+
+   /* Call emulate_point_sprite to find or create a transformed
+    * geometry shader for supporting point sprite.
+    */
+   new_gs = (struct svga_geometry_shader *)
+               emulate_point_sprite(svga, &orig_gs->base, tokens);
+
+   /* If this is the first time creating a geometry shader to
+    * support vertex point size, then add the new geometry shader
+    * to the vertex shader.
+    */
+   if (vs->gs == NULL) {
+      vs->gs = new_gs;
+   }
+
+   return &new_gs->base;
+}
+
+/* update_tgsi_transform provides a hook to transform a shader if needed.
+ */
+static enum pipe_error
+update_tgsi_transform(struct svga_context *svga, unsigned dirty)
+{
+   struct svga_geometry_shader *gs = svga->curr.user_gs;   /* current gs */
+   struct svga_vertex_shader *vs = svga->curr.vs;     /* currently bound vs */
+   struct svga_shader *orig_gs;                       /* original gs */
+   struct svga_shader *new_gs;                        /* new gs */
+
+   if (!svga_have_vgpu10(svga))
+      return PIPE_OK;
+
+   if (svga->curr.reduced_prim == PIPE_PRIM_POINTS) {
+      /* If the current prim type is POINTS and the current geometry shader
+       * emits wide points, transform the shader to emulate wide points using
+       * quads.
+       */
+      if (gs != NULL && (gs->base.info.writes_psize || gs->wide_point)) {
+         orig_gs = gs->base.parent ? gs->base.parent : &gs->base;
+         new_gs = emulate_point_sprite(svga, orig_gs, orig_gs->tokens);
+      }
+
+      /* If there is not an active geometry shader and the current vertex
+       * shader emits wide point then create a new geometry shader to emulate
+       * wide point.
+       */
+      else if (gs == NULL &&
+               (svga->curr.rast->pointsize > 1.0 ||
+                vs->base.info.writes_psize)) {
+         new_gs = add_point_sprite_shader(svga);
+      }
+      else {
+         /* use the user's GS */
+         bind_gs_state(svga, svga->curr.user_gs);
+      }
+   }
+   else if (svga->curr.gs != svga->curr.user_gs) {
+      /* If current primitive type is not POINTS, then make sure
+       * we don't bind to any of the generated geometry shader
+       */
+      bind_gs_state(svga, svga->curr.user_gs);
+   }
+   (void) new_gs;    /* silence the unused var warning */
+
+   return PIPE_OK;
+}
+
+struct svga_tracked_state svga_need_tgsi_transform =
+{
+   "transform shader for optimization",
+   (SVGA_NEW_VS |
+    SVGA_NEW_FS |
+    SVGA_NEW_GS |
+    SVGA_NEW_REDUCED_PRIMITIVE |
+    SVGA_NEW_RAST),
+   update_tgsi_transform
+};