/*
 * Copyright (c) 2014-2024 Broadcom. All Rights Reserved.
 * The term “Broadcom” refers to Broadcom Inc.
 * and/or its subsidiaries.
 * SPDX-License-Identifier: MIT
 */

#include "util/u_inlines.h"
#include "util/u_memory.h"
#include "util/u_bitmask.h"
#include "translate/translate.h"

#include "svga_context.h"
#include "svga_cmd.h"
#include "svga_shader.h"
#include "svga_tgsi.h"
#include "svga_streamout.h"
#include "svga_format.h"

/**
 * If we fail to compile a geometry shader we'll use a dummy/fallback shader
 * that simply emits the incoming vertices.
 */
static const struct tgsi_token *
get_dummy_geometry_shader(void)
{
   //XXX
   return NULL;
}


struct svga_shader_variant *
svga_get_compiled_dummy_geometry_shader(struct svga_context *svga,
                                        struct svga_shader *shader,
                                        const struct svga_compile_key *key)
{
   const struct tgsi_token *dummy = get_dummy_geometry_shader();
   struct svga_shader_variant *variant;
   struct svga_geometry_shader *gs = (struct svga_geometry_shader *)shader;

   if (!dummy)
      return NULL;

   FREE((void *) gs->base.tokens);
   gs->base.tokens = dummy;
   svga_tgsi_scan_shader(&gs->base);
   variant = svga_tgsi_compile_shader(svga, shader, key);

   return variant;
}


static void
make_gs_key(struct svga_context *svga, struct svga_compile_key *key)
{
   struct svga_geometry_shader *gs = svga->curr.gs;

   memset(key, 0, sizeof *key);

   /*
    * SVGA_NEW_TEXTURE_BINDING | SVGA_NEW_SAMPLER
    */
   svga_init_shader_key_common(svga, MESA_SHADER_GEOMETRY, &gs->base, key);

   memcpy(key->generic_remap_table, gs->generic_remap_table,
          sizeof(gs->generic_remap_table));

   key->gs.vs_generic_outputs = svga->curr.vs->base.info.generic_outputs_mask;

   key->gs.need_prescale = svga->state.hw_clear.prescale[0].enabled;

   key->gs.writes_psize = gs->base.info.writes_psize;
   key->gs.wide_point = gs->wide_point;
   key->gs.writes_viewport_index = gs->base.info.writes_viewport_index;
   if (key->gs.writes_viewport_index) {
      key->gs.num_prescale = svga->state.hw_clear.num_prescale;
   } else {
      key->gs.num_prescale = 1;
   }
   key->sprite_coord_enable = svga->curr.rast->templ.sprite_coord_enable;
   key->sprite_origin_lower_left = (svga->curr.rast->templ.sprite_coord_mode
                                    == PIPE_SPRITE_COORD_LOWER_LEFT);

   /* SVGA_NEW_RAST */
   key->clip_plane_enable = svga->curr.rast->templ.clip_plane_enable;

   /* Mark this as the last shader in the vertex processing stage */
   key->last_vertex_stage = 1;
}


static enum pipe_error
emit_hw_gs(struct svga_context *svga, uint64_t dirty)
{
   struct svga_shader_variant *variant;
   struct svga_geometry_shader *gs = svga->curr.gs;
   enum pipe_error ret = PIPE_OK;
   struct svga_compile_key key;

   assert(svga_have_vgpu10(svga));

   SVGA_STATS_TIME_PUSH(svga_sws(svga), SVGA_STATS_TIME_EMITGS);

   /* If there's a user-defined GS, we should have a pointer to a derived
    * GS.  This should have been resolved in update_tgsi_transform().
    */
   if (svga->curr.user_gs)
      assert(svga->curr.gs);

   if (!gs) {
      if (svga->state.hw_draw.gs != NULL) {

         /** The previous geometry shader is made inactive.
          *  Needs to unbind the geometry shader.
          */
         ret = svga_set_shader(svga, SVGA3D_SHADERTYPE_GS, NULL);
         if (ret != PIPE_OK)
            goto done;
         svga->state.hw_draw.gs = NULL;
      }
      goto done;
   }

   /* If there is stream output info for this geometry shader, then use
    * it instead of the one from the vertex shader.
    */
   if (svga_have_gs_streamout(svga)) {
      ret = svga_set_stream_output(svga, gs->base.stream_output);
      if (ret != PIPE_OK) {
         goto done;
      }
   }
   else if (!svga_have_vs_streamout(svga)) {
      /* turn off stream out */
      ret = svga_set_stream_output(svga, NULL);
      if (ret != PIPE_OK) {
         goto done;
      }
   }

   /* SVGA_NEW_NEED_SWTNL */
   if (svga->state.sw.need_swtnl && !svga_have_vgpu10(svga)) {
      /* No geometry shader is needed */
      variant = NULL;
   }
   else {
      make_gs_key(svga, &key);

      /* See if we already have a GS variant that matches the key */
      variant = svga_search_shader_key(&gs->base, &key);

      if (!variant) {
         ret = svga_compile_shader(svga, &gs->base, &key, &variant);
         if (ret != PIPE_OK)
            goto done;
      }
   }

   if (variant != svga->state.hw_draw.gs) {
      /* Bind the new variant */
      ret = svga_set_shader(svga, SVGA3D_SHADERTYPE_GS, variant);
      if (ret != PIPE_OK)
         goto done;

      svga->rebind.flags.gs = false;
      svga->dirty |= SVGA_NEW_GS_VARIANT;
      svga->state.hw_draw.gs = variant;
   }

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

struct svga_tracked_state svga_hw_gs =
{
   "geometry shader (hwtnl)",
   (SVGA_NEW_VS |
    SVGA_NEW_FS |
    SVGA_NEW_GS |
    SVGA_NEW_TEXTURE_BINDING |
    SVGA_NEW_SAMPLER |
    SVGA_NEW_RAST |
    SVGA_NEW_NEED_SWTNL |
    SVGA_NEW_GS_RAW_BUFFER),
   emit_hw_gs
};
