/**********************************************************
 * Copyright 2008-2009 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_helpers.h"
#include "util/u_inlines.h"
#include "util/u_prim.h"
#include "util/u_prim_restart.h"

#include "svga_context.h"
#include "svga_draw.h"
#include "svga_shader.h"
#include "svga_surface.h"
#include "svga_swtnl.h"
#include "svga_debug.h"
#include "svga_resource_buffer.h"

/* Returns TRUE if we are currently using flat shading.
 */
static boolean
is_using_flat_shading(const struct svga_context *svga)
{
   return
      svga->state.hw_draw.fs ? svga->state.hw_draw.fs->uses_flat_interp : FALSE;
}


static enum pipe_error
retry_draw_range_elements(struct svga_context *svga,
                          struct pipe_resource *index_buffer,
                          unsigned index_size,
                          int index_bias,
                          unsigned min_index,
                          unsigned max_index,
                          enum pipe_prim_type prim,
                          unsigned start,
                          unsigned count,
                          unsigned start_instance,
                          unsigned instance_count)
{
   enum pipe_error ret;

   SVGA_STATS_TIME_PUSH(svga_sws(svga), SVGA_STATS_TIME_DRAWELEMENTS);

   for (unsigned try = 0; try < 2; try++) {
      ret = svga_hwtnl_draw_range_elements(svga->hwtnl,
                                           index_buffer, index_size,
                                           index_bias,
                                           min_index, max_index,
                                           prim, start, count,
                                           start_instance, instance_count);
      if (ret == PIPE_OK)
         break;
      svga_context_flush(svga, NULL);
   }

   SVGA_STATS_TIME_POP(svga_sws(svga));
   return ret;
}


static enum pipe_error
retry_draw_arrays(struct svga_context *svga,
                  enum pipe_prim_type prim, unsigned start, unsigned count,
                  unsigned start_instance, unsigned instance_count)
{
   enum pipe_error ret;

   SVGA_STATS_TIME_PUSH(svga_sws(svga), SVGA_STATS_TIME_DRAWARRAYS);

   for (unsigned try = 0; try < 2; try++) {
      ret = svga_hwtnl_draw_arrays(svga->hwtnl, prim, start, count,
                                   start_instance, instance_count);
      if (ret == PIPE_OK)
         break;
      svga_context_flush(svga, NULL);
   }

   SVGA_STATS_TIME_POP(svga_sws(svga));
   return ret;
}


/**
 * Determine if we need to implement primitive restart with a fallback
 * path which breaks the original primitive into sub-primitive at the
 * restart indexes.
 */
static boolean
need_fallback_prim_restart(const struct svga_context *svga,
                           const struct pipe_draw_info *info)
{
   if (info->primitive_restart && info->index_size) {
      if (!svga_have_vgpu10(svga))
         return TRUE;
      else if (!svga->state.sw.need_swtnl) {
         if (info->index_size == 1)
            return TRUE; /* no device support for 1-byte indexes */
         else if (info->index_size == 2)
            return info->restart_index != 0xffff;
         else
            return info->restart_index != 0xffffffff;
      }
   }

   return FALSE;
}


static void
svga_draw_vbo(struct pipe_context *pipe, const struct pipe_draw_info *info)
{
   struct svga_context *svga = svga_context(pipe);
   enum pipe_prim_type reduced_prim = u_reduced_prim(info->mode);
   unsigned count = info->count;
   enum pipe_error ret = 0;
   boolean needed_swtnl;
   struct pipe_resource *indexbuf =
      info->has_user_indices ? NULL : info->index.resource;

   SVGA_STATS_TIME_PUSH(svga_sws(svga), SVGA_STATS_TIME_DRAWVBO);

   svga->hud.num_draw_calls++;  /* for SVGA_QUERY_NUM_DRAW_CALLS */

   if (u_reduced_prim(info->mode) == PIPE_PRIM_TRIANGLES &&
       svga->curr.rast->templ.cull_face == PIPE_FACE_FRONT_AND_BACK)
      goto done;

   /* Upload a user index buffer. */
   unsigned index_offset = 0;
   if (info->index_size && info->has_user_indices &&
       !util_upload_index_buffer(pipe, info, &indexbuf, &index_offset)) {
      goto done;
   }

   /*
    * Mark currently bound target surfaces as dirty
    * doesn't really matter if it is done before drawing.
    *
    * TODO If we ever normaly return something other then
    * true we should not mark it as dirty then.
    */
   svga_mark_surfaces_dirty(svga_context(pipe));

   if (svga->curr.reduced_prim != reduced_prim) {
      svga->curr.reduced_prim = reduced_prim;
      svga->dirty |= SVGA_NEW_REDUCED_PRIMITIVE;
   }

   if (need_fallback_prim_restart(svga, info)) {
      enum pipe_error r;
      r = util_draw_vbo_without_prim_restart(pipe, info);
      assert(r == PIPE_OK);
      (void) r;
      goto done;
   }

   if (!u_trim_pipe_prim(info->mode, &count))
      goto done;

   needed_swtnl = svga->state.sw.need_swtnl;

   svga_update_state_retry(svga, SVGA_STATE_NEED_SWTNL);

   if (svga->state.sw.need_swtnl) {
      svga->hud.num_fallbacks++;  /* for SVGA_QUERY_NUM_FALLBACKS */
      if (!needed_swtnl) {
         /*
          * We're switching from HW to SW TNL.  SW TNL will require mapping all
          * currently bound vertex buffers, some of which may already be
          * referenced in the current command buffer as result of previous HW
          * TNL. So flush now, to prevent the context to flush while a referred
          * vertex buffer is mapped.
          */

         svga_context_flush(svga, NULL);
      }

      /* Avoid leaking the previous hwtnl bias to swtnl */
      svga_hwtnl_set_index_bias(svga->hwtnl, 0);
      ret = svga_swtnl_draw_vbo(svga, info, indexbuf, index_offset);
   }
   else {
      if (!svga_update_state_retry(svga, SVGA_STATE_HW_DRAW)) {
         static const char *msg = "State update failed, skipping draw call";
         debug_printf("%s\n", msg);
         pipe_debug_message(&svga->debug.callback, INFO, "%s", msg);
         goto done;
      }

      svga_hwtnl_set_fillmode(svga->hwtnl, svga->curr.rast->hw_fillmode);

      /** determine if flatshade is to be used after svga_update_state()
       *  in case the fragment shader is changed.
       */
      svga_hwtnl_set_flatshade(svga->hwtnl,
                               svga->curr.rast->templ.flatshade ||
                               is_using_flat_shading(svga),
                               svga->curr.rast->templ.flatshade_first);

      if (info->index_size && indexbuf) {
         unsigned offset;

         assert(index_offset % info->index_size == 0);
         offset = index_offset / info->index_size;

         ret = retry_draw_range_elements(svga,
                                         indexbuf,
                                         info->index_size,
                                         info->index_bias,
                                         info->min_index,
                                         info->max_index,
                                         info->mode,
                                         info->start + offset,
                                         count,
                                         info->start_instance,
                                         info->instance_count);
      }
      else {
         ret = retry_draw_arrays(svga, info->mode, info->start, count,
                                 info->start_instance, info->instance_count);
      }
   }

   /* XXX: Silence warnings, do something sensible here? */
   (void)ret;

   if (SVGA_DEBUG & DEBUG_FLUSH) {
      svga_hwtnl_flush_retry(svga);
      svga_context_flush(svga, NULL);
   }

done:
   if (info->index_size && info->index.resource != indexbuf)
      pipe_resource_reference(&indexbuf, NULL);
   SVGA_STATS_TIME_POP(svga_sws(svga));
}


void
svga_init_draw_functions(struct svga_context *svga)
{
   svga->pipe.draw_vbo = svga_draw_vbo;
}