/*
 * Copyright © Microsoft 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.
 */

#include "d3d12_context.h"
#include "d3d12_compiler.h"
#include "d3d12_debug.h"
#include "d3d12_format.h"
#include "d3d12_resource.h"
#include "d3d12_screen.h"

#include "util/u_blitter.h"
#include "util/format/u_format.h"

#include "nir_to_dxil.h"
#include "nir_builder.h"

static void
copy_buffer_region_no_barriers(struct d3d12_context *ctx,
                               struct d3d12_resource *dst,
                               uint64_t dst_offset,
                               struct d3d12_resource *src,
                               uint64_t src_offset,
                               uint64_t size)
{
   uint64_t dst_off, src_off;
   ID3D12Resource *dst_buf = d3d12_resource_underlying(dst, &dst_off);
   ID3D12Resource *src_buf = d3d12_resource_underlying(src, &src_off);

   ctx->cmdlist->CopyBufferRegion(dst_buf, dst_offset + dst_off,
                                  src_buf, src_offset + src_off,
                                  size);
}

static bool
is_resolve(const struct pipe_blit_info *info)
{
   return info->src.resource->nr_samples > 1 &&
          info->dst.resource->nr_samples <= 1;
}

static bool
resolve_supported(const struct pipe_blit_info *info)
{
   assert(is_resolve(info));

   // check for unsupported operations
   if (util_format_is_depth_or_stencil(info->src.format) &&
       info->mask != PIPE_MASK_Z) {
      return false;
   } else {
      if (util_format_get_mask(info->dst.format) != info->mask ||
          util_format_get_mask(info->src.format) != info->mask)
         return false;
   }

   if (info->filter != PIPE_TEX_FILTER_NEAREST ||
       info->scissor_enable ||
       info->num_window_rectangles > 0 ||
       info->alpha_blend)
      return false;

   // formats need to match
   struct d3d12_resource *src = d3d12_resource(info->src.resource);
   struct d3d12_resource *dst = d3d12_resource(info->dst.resource);
   if (src->dxgi_format != dst->dxgi_format)
      return false;

   if (util_format_is_pure_integer(src->base.format))
      return false;

   // sizes needs to match
   if (info->src.box.width != info->dst.box.width ||
       info->src.box.height != info->dst.box.height)
      return false;

   // can only resolve full subresource
   if (info->src.box.width != (int)u_minify(info->src.resource->width0,
                                            info->src.level) ||
       info->src.box.height != (int)u_minify(info->src.resource->height0,
                                             info->src.level) ||
       info->dst.box.width != (int)u_minify(info->dst.resource->width0,
                                            info->dst.level) ||
       info->dst.box.height != (int)u_minify(info->dst.resource->height0,
                                             info->dst.level))
      return false;

   return true;
}

static void
blit_resolve(struct d3d12_context *ctx, const struct pipe_blit_info *info)
{
   struct d3d12_batch *batch = d3d12_current_batch(ctx);
   struct d3d12_resource *src = d3d12_resource(info->src.resource);
   struct d3d12_resource *dst = d3d12_resource(info->dst.resource);

   d3d12_transition_resource_state(ctx, src,
                                   D3D12_RESOURCE_STATE_RESOLVE_SOURCE,
                                   D3D12_BIND_INVALIDATE_FULL);
   d3d12_transition_resource_state(ctx, dst,
                                   D3D12_RESOURCE_STATE_RESOLVE_DEST,
                                   D3D12_BIND_INVALIDATE_FULL);

   d3d12_apply_resource_states(ctx);

   d3d12_batch_reference_resource(batch, src);
   d3d12_batch_reference_resource(batch, dst);

   DXGI_FORMAT dxgi_format = d3d12_get_resource_srv_format(src->base.format, src->base.target);

   assert(src->dxgi_format == dst->dxgi_format);
   ctx->cmdlist->ResolveSubresource(
      d3d12_resource_resource(dst), info->dst.level,
      d3d12_resource_resource(src), info->src.level,
      dxgi_format);
}

static bool
formats_are_copy_compatible(enum pipe_format src, enum pipe_format dst)
{
   if (src == dst)
      return true;

   /* We can skip the stencil copy */
   if (util_format_get_depth_only(src) == dst ||
       util_format_get_depth_only(dst) == src)
      return true;

   return false;
}

static bool
box_fits(const struct pipe_box *box, const struct pipe_resource *res, int level)
{
   unsigned lwidth = u_minify(res->width0, level);
   unsigned lheight= u_minify(res->height0, level);
   unsigned ldepth = res->target == PIPE_TEXTURE_3D ? u_minify(res->depth0, level) :
                                                      res->array_size;

   unsigned wb = box->x;
   unsigned we = box->x + box->width;

   unsigned hb = box->y;
   unsigned he = box->y + box->height;

   unsigned db = box->z;
   unsigned de = box->z + box->depth;

   return (wb <= lwidth && we <= lwidth &&
           hb <= lheight && he <= lheight &&
           db <= ldepth && de <= ldepth);
}

static bool
direct_copy_supported(struct d3d12_screen *screen,
                      const struct pipe_blit_info *info,
                      bool have_predication)
{
   if (info->scissor_enable || info->alpha_blend ||
       (have_predication && info->render_condition_enable) ||
       MAX2(info->src.resource->nr_samples, 1) != MAX2(info->dst.resource->nr_samples, 1)) {
      return false;
   }

   if (!formats_are_copy_compatible(info->src.format, info->dst.format))
      return false;

   if (util_format_is_depth_or_stencil(info->src.format) && !(info->mask & PIPE_MASK_ZS)) {
      return false;
   }

   if (!util_format_is_depth_or_stencil(info->src.format)) {
      if (util_format_get_mask(info->dst.format) != info->mask ||
          util_format_get_mask(info->src.format) != info->mask)
         return false;
   }

   if (abs(info->src.box.height) != info->dst.box.height) {
      return false;
   }

   if (info->src.box.height != info->dst.box.height &&
       (!util_format_is_depth_or_stencil(info->src.format) ||
        screen->opts2.ProgrammableSamplePositionsTier ==
        D3D12_PROGRAMMABLE_SAMPLE_POSITIONS_TIER_NOT_SUPPORTED)) {
      return false;
   }

   if (!box_fits(&info->dst.box, info->dst.resource, info->dst.level)) {
      return false;
   }
   if (!box_fits(&info->src.box, info->src.resource, info->src.level)) {
      return false;
   }

   if (info->src.box.width != info->dst.box.width) {
      return false;
   }

   if (info->src.box.depth != info->dst.box.depth) {
      return false;
   }

   if ((screen->opts2.ProgrammableSamplePositionsTier ==
        D3D12_PROGRAMMABLE_SAMPLE_POSITIONS_TIER_NOT_SUPPORTED &&
        (info->src.resource->bind & PIPE_BIND_DEPTH_STENCIL ||
         info->dst.resource->bind & PIPE_BIND_DEPTH_STENCIL)) ||
        info->src.resource->nr_samples > 1) {

      if (info->dst.box.x != 0 ||
          info->dst.box.y != 0 ||
          info->dst.box.z != 0)
         return false;

      if (info->src.box.x != 0 ||
          info->src.box.y != 0 ||
          info->src.box.z != 0 ||
          info->src.box.width != (int)u_minify(info->src.resource->width0,
                                               info->src.level) ||
          info->src.box.height != (int)u_minify(info->src.resource->height0,
                                                info->src.level) ||
          info->src.box.depth != (int)u_minify(info->src.resource->depth0,
                                               info->src.level))
         return false;
   }

   return true;
}

inline static unsigned
get_subresource_id(enum pipe_texture_target target, unsigned subres, unsigned stride,
                   unsigned z, unsigned *updated_z)
{
   if (d3d12_subresource_id_uses_layer(target)) {
      subres += stride * z;
      if (updated_z)
         *updated_z = 0;
   }
   return subres;
}

static void
copy_subregion_no_barriers(struct d3d12_context *ctx,
                           struct d3d12_resource *dst,
                           unsigned dst_level,
                           unsigned dstx, unsigned dsty, unsigned dstz,
                           struct d3d12_resource *src,
                           unsigned src_level,
                           const struct pipe_box *psrc_box,
                           unsigned mask)
{
   UNUSED struct d3d12_screen *screen = d3d12_screen(ctx->base.screen);
   D3D12_TEXTURE_COPY_LOCATION src_loc, dst_loc;
   unsigned src_z = psrc_box->z;

   int src_subres_stride = src->base.last_level + 1;
   int dst_subres_stride = dst->base.last_level + 1;

   int src_array_size = src->base.array_size;
   int dst_array_size = dst->base.array_size;

   if (dst->base.target == PIPE_TEXTURE_CUBE)
      dst_array_size *= 6;

   if (src->base.target == PIPE_TEXTURE_CUBE)
      src_array_size *= 6;

   int stencil_src_res_offset = 1;
   int stencil_dst_res_offset = 1;

   int src_nres = 1;
   int dst_nres = 1;

   if (dst->base.format == PIPE_FORMAT_Z24_UNORM_S8_UINT ||
       dst->base.format == PIPE_FORMAT_S8_UINT_Z24_UNORM ||
       dst->base.format == PIPE_FORMAT_Z32_FLOAT_S8X24_UINT) {
      stencil_dst_res_offset = dst_subres_stride * dst_array_size;
      src_nres = 2;
   }

   if (src->base.format == PIPE_FORMAT_Z24_UNORM_S8_UINT ||
       src->base.format == PIPE_FORMAT_S8_UINT_Z24_UNORM ||
       dst->base.format == PIPE_FORMAT_Z32_FLOAT_S8X24_UINT) {
      stencil_src_res_offset = src_subres_stride * src_array_size;
      dst_nres = 2;
   }

   static_assert(PIPE_MASK_S == 0x20 && PIPE_MASK_Z == 0x10, "unexpected ZS format mask");
   int nsubres = MIN2(src_nres, dst_nres);
   unsigned subresource_copy_mask = nsubres > 1 ? mask >> 4 : 1;

   for (int subres = 0; subres < nsubres; ++subres) {

      if (!(subresource_copy_mask & (1 << subres)))
         continue;

      src_loc.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
      src_loc.SubresourceIndex = get_subresource_id(src->base.target, src_level, src_subres_stride, src_z, &src_z) +
                                 subres * stencil_src_res_offset;
      src_loc.pResource = d3d12_resource_resource(src);

      dst_loc.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
      dst_loc.SubresourceIndex = get_subresource_id(dst->base.target, dst_level, dst_subres_stride, dstz, &dstz) +
                                 subres * stencil_dst_res_offset;
      dst_loc.pResource = d3d12_resource_resource(dst);

      if (psrc_box->x == 0 && psrc_box->y == 0 && psrc_box->z == 0 &&
          psrc_box->width == (int)u_minify(src->base.width0, src_level) &&
          psrc_box->height == (int)u_minify(src->base.height0, src_level) &&
          psrc_box->depth == (int)u_minify(src->base.depth0, src_level)) {

         assert((dstx == 0 && dsty == 0 && dstz == 0) ||
                screen->opts2.ProgrammableSamplePositionsTier !=
                D3D12_PROGRAMMABLE_SAMPLE_POSITIONS_TIER_NOT_SUPPORTED ||
                (!util_format_is_depth_or_stencil(dst->base.format) &&
                 !util_format_is_depth_or_stencil(src->base.format) &&
                  dst->base.nr_samples <= 1 &&
                  src->base.nr_samples <= 1));

         ctx->cmdlist->CopyTextureRegion(&dst_loc, dstx, dsty, dstz,
                                         &src_loc, NULL);

      } else {
         D3D12_BOX src_box;
         src_box.left = psrc_box->x;
         src_box.right = MIN2(psrc_box->x + psrc_box->width, (int)u_minify(src->base.width0, src_level));
         src_box.top = psrc_box->y;
         src_box.bottom = MIN2(psrc_box->y + psrc_box->height, (int)u_minify(src->base.height0, src_level));
         src_box.front = src_z;
         src_box.back = src_z + psrc_box->depth;

         assert((screen->opts2.ProgrammableSamplePositionsTier !=
                 D3D12_PROGRAMMABLE_SAMPLE_POSITIONS_TIER_NOT_SUPPORTED ||
                 (!util_format_is_depth_or_stencil(dst->base.format) &&
                  !util_format_is_depth_or_stencil(src->base.format))) &&
                dst->base.nr_samples <= 1 &&
                src->base.nr_samples <= 1);

         ctx->cmdlist->CopyTextureRegion(&dst_loc, dstx, dsty, dstz,
                                         &src_loc, &src_box);
      }
   }
}

static void
copy_resource_y_flipped_no_barriers(struct d3d12_context *ctx,
                                    struct d3d12_resource *dst,
                                    unsigned dst_level,
                                    const struct pipe_box *pdst_box,
                                    struct d3d12_resource *src,
                                    unsigned src_level,
                                    const struct pipe_box *psrc_box,
                                    unsigned mask)
{
   if (D3D12_DEBUG_BLIT & d3d12_debug) {
      debug_printf("D3D12 BLIT as COPY: from %s@%d %dx%dx%d + %dx%dx%d\n",
                   util_format_name(src->base.format), src_level,
                   psrc_box->x, psrc_box->y, psrc_box->z,
                   psrc_box->width, psrc_box->height, psrc_box->depth);
      debug_printf("      to   %s@%d %dx%dx%d\n",
                   util_format_name(dst->base.format), dst_level,
                   pdst_box->x, pdst_box->y, pdst_box->z);
   }

   struct pipe_box src_box = *psrc_box;
   int src_inc = psrc_box->height > 0 ? 1 : -1;
   int dst_inc = pdst_box->height > 0 ? 1 : -1;
   src_box.height = 1;
   int rows_to_copy = abs(psrc_box->height);

   if (psrc_box->height < 0)
      --src_box.y;

   for (int y = 0, dest_y = pdst_box->y; y < rows_to_copy;
        ++y, src_box.y += src_inc, dest_y += dst_inc) {
      copy_subregion_no_barriers(ctx, dst, dst_level,
                                 pdst_box->x, dest_y, pdst_box->z,
                                 src, src_level, &src_box, mask);
   }
}

void
d3d12_direct_copy(struct d3d12_context *ctx,
                  struct d3d12_resource *dst,
                  unsigned dst_level,
                  const struct pipe_box *pdst_box,
                  struct d3d12_resource *src,
                  unsigned src_level,
                  const struct pipe_box *psrc_box,
                  unsigned mask)
{
   struct d3d12_batch *batch = d3d12_current_batch(ctx);

   unsigned src_subres = get_subresource_id(src->base.target, src_level, src->base.last_level + 1,
                                            psrc_box->z, nullptr);
   unsigned dst_subres = get_subresource_id(dst->base.target, dst_level, dst->base.last_level + 1,
                                            pdst_box->z, nullptr);

   if (D3D12_DEBUG_BLIT & d3d12_debug)
      debug_printf("BLIT: Direct copy from subres %d to subres  %d\n",
                   src_subres, dst_subres);

   d3d12_transition_subresources_state(ctx, src, src_subres, 1, 0, 1,
                                       d3d12_get_format_start_plane(src->base.format),
                                       d3d12_get_format_num_planes(src->base.format),
                                       D3D12_RESOURCE_STATE_COPY_SOURCE,
                                       D3D12_BIND_INVALIDATE_FULL);

   d3d12_transition_subresources_state(ctx, dst, dst_subres, 1, 0, 1,
                                       d3d12_get_format_start_plane(dst->base.format),
                                       d3d12_get_format_num_planes(dst->base.format),
                                       D3D12_RESOURCE_STATE_COPY_DEST,
                                       D3D12_BIND_INVALIDATE_FULL);

   d3d12_apply_resource_states(ctx);

   d3d12_batch_reference_resource(batch, src);
   d3d12_batch_reference_resource(batch, dst);

   if (src->base.target == PIPE_BUFFER) {
      copy_buffer_region_no_barriers(ctx, dst, pdst_box->x,
                                     src, psrc_box->x, psrc_box->width);
   } else if (psrc_box->height == pdst_box->height) {
      /* No flipping, we can forward this directly to resource_copy_region */
      copy_subregion_no_barriers(ctx, dst, dst_level,
                                 pdst_box->x, pdst_box->y, pdst_box->z,
                                 src, src_level, psrc_box, mask);
   } else {
      assert(psrc_box->height == -pdst_box->height);
      copy_resource_y_flipped_no_barriers(ctx, dst, dst_level, pdst_box,
                                          src, src_level, psrc_box, mask);
   }
}

static bool
is_same_resource(const struct pipe_blit_info *info)
{
   return d3d12_resource_resource(d3d12_resource(info->src.resource)) ==
             d3d12_resource_resource(d3d12_resource(info->dst.resource)) &&
          info->src.level == info->dst.level;
}

static struct pipe_resource *
create_staging_resource(struct d3d12_context *ctx,
                        struct d3d12_resource *src,
                        unsigned src_level,
                        const struct pipe_box *src_box,
                        struct pipe_box *dst_box,
                        unsigned mask)

{
   struct pipe_resource templ = {};
   struct pipe_resource *staging_res;
   struct pipe_box copy_src;

   u_box_3d(MIN2(src_box->x, src_box->x + src_box->width),
            MIN2(src_box->y, src_box->y + src_box->height),
            MIN2(src_box->z, src_box->z + src_box->depth),
            abs(src_box->width), abs(src_box->height), abs(src_box->depth),
            &copy_src);

   templ.format = src->base.format;
   templ.width0 = copy_src.width;
   templ.height0 = copy_src.height;
   templ.depth0 = copy_src.depth;
   templ.array_size = 1;
   templ.nr_samples = 1;
   templ.nr_storage_samples = 1;
   templ.usage = PIPE_USAGE_STAGING;
   templ.bind = util_format_is_depth_or_stencil(templ.format) ? PIPE_BIND_DEPTH_STENCIL : PIPE_BIND_RENDER_TARGET;
   templ.target = src->base.target;

   staging_res = ctx->base.screen->resource_create(ctx->base.screen, &templ);

   dst_box->x = 0;
   dst_box->y = 0;
   dst_box->z = 0;
   dst_box->width = copy_src.width;
   dst_box->height = copy_src.height;
   dst_box->depth = copy_src.depth;

   d3d12_direct_copy(ctx, d3d12_resource(staging_res), 0, dst_box,
                     src, src_level, &copy_src, mask);

   if (src_box->width < 0) {
      dst_box->x = dst_box->width;
      dst_box->width = src_box->width;
   }

   if (src_box->height < 0) {
      dst_box->y = dst_box->height;
      dst_box->height = src_box->height;
   }

   if (src_box->depth < 0) {
      dst_box->z = dst_box->depth;
      dst_box->depth = src_box->depth;
   }
   return staging_res;
}

static void
blit_same_resource(struct d3d12_context *ctx,
                   const struct pipe_blit_info *info)
{
   struct pipe_blit_info dst_info = *info;

   dst_info.src.level = 0;
   dst_info.src.resource = create_staging_resource(ctx, d3d12_resource(info->src.resource),
                                                   info->src.level,
                                                   &info->src.box,
                                                   &dst_info.src.box, PIPE_MASK_RGBAZS);
   ctx->base.blit(&ctx->base, &dst_info);
   pipe_resource_reference(&dst_info.src.resource, NULL);
}

static void
util_blit_save_state(struct d3d12_context *ctx)
{
   util_blitter_save_blend(ctx->blitter, ctx->gfx_pipeline_state.blend);
   util_blitter_save_depth_stencil_alpha(ctx->blitter, ctx->gfx_pipeline_state.zsa);
   util_blitter_save_vertex_elements(ctx->blitter, ctx->gfx_pipeline_state.ves);
   util_blitter_save_stencil_ref(ctx->blitter, &ctx->stencil_ref);
   util_blitter_save_rasterizer(ctx->blitter, ctx->gfx_pipeline_state.rast);
   util_blitter_save_fragment_shader(ctx->blitter, ctx->gfx_stages[PIPE_SHADER_FRAGMENT]);
   util_blitter_save_vertex_shader(ctx->blitter, ctx->gfx_stages[PIPE_SHADER_VERTEX]);
   util_blitter_save_geometry_shader(ctx->blitter, ctx->gfx_stages[PIPE_SHADER_GEOMETRY]);

   util_blitter_save_framebuffer(ctx->blitter, &ctx->fb);
   util_blitter_save_viewport(ctx->blitter, ctx->viewport_states);
   util_blitter_save_scissor(ctx->blitter, ctx->scissor_states);
   util_blitter_save_fragment_sampler_states(ctx->blitter,
                                             ctx->num_samplers[PIPE_SHADER_FRAGMENT],
                                             (void **)ctx->samplers[PIPE_SHADER_FRAGMENT]);
   util_blitter_save_fragment_sampler_views(ctx->blitter,
                                            ctx->num_sampler_views[PIPE_SHADER_FRAGMENT],
                                            ctx->sampler_views[PIPE_SHADER_FRAGMENT]);
   util_blitter_save_fragment_constant_buffer_slot(ctx->blitter, ctx->cbufs[PIPE_SHADER_FRAGMENT]);
   util_blitter_save_vertex_buffer_slot(ctx->blitter, ctx->vbs);
   util_blitter_save_sample_mask(ctx->blitter, ctx->gfx_pipeline_state.sample_mask);
   util_blitter_save_so_targets(ctx->blitter, ctx->gfx_pipeline_state.num_so_targets, ctx->so_targets);
}

static void
util_blit(struct d3d12_context *ctx,
          const struct pipe_blit_info *info)
{
   util_blit_save_state(ctx);

   util_blitter_blit(ctx->blitter, info);
}

static bool
resolve_stencil_supported(struct d3d12_context *ctx,
                          const struct pipe_blit_info *info)
{
   assert(is_resolve(info));

   if (!util_format_is_depth_or_stencil(info->src.format) ||
       !(info->mask & PIPE_MASK_S))
      return false;

   if (info->mask & PIPE_MASK_Z) {
      struct pipe_blit_info new_info = *info;
      new_info.mask = PIPE_MASK_Z;
      if (!resolve_supported(&new_info) &&
          !util_blitter_is_blit_supported(ctx->blitter, &new_info))
         return false;
   }

   struct pipe_blit_info new_info = *info;
   new_info.dst.format = PIPE_FORMAT_R8_UINT;
   return util_blitter_is_blit_supported(ctx->blitter, &new_info);
}

static struct pipe_resource *
create_tmp_resource(struct pipe_screen *screen,
                    const struct pipe_blit_info *info)
{
   struct pipe_resource tpl = {};
   tpl.width0 = info->dst.box.width;
   tpl.height0 = info->dst.box.height;
   tpl.depth0 = info->dst.box.depth;
   tpl.array_size = 1;
   tpl.format = PIPE_FORMAT_R8_UINT;
   tpl.target = info->dst.resource->target;
   tpl.nr_samples = info->dst.resource->nr_samples;
   tpl.nr_storage_samples = info->dst.resource->nr_storage_samples;
   tpl.usage = PIPE_USAGE_STREAM;
   tpl.bind = PIPE_BIND_RENDER_TARGET | PIPE_BIND_SAMPLER_VIEW;
   return screen->resource_create(screen, &tpl);
}

static void *
get_stencil_resolve_vs(struct d3d12_context *ctx)
{
   if (ctx->stencil_resolve_vs)
      return ctx->stencil_resolve_vs;

   nir_builder b = nir_builder_init_simple_shader(MESA_SHADER_VERTEX,
                                                  dxil_get_nir_compiler_options(),
                                                  "linear_blit_vs");

   const struct glsl_type *vec4 = glsl_vec4_type();
   nir_variable *pos_in = nir_variable_create(b.shader, nir_var_shader_in,
                                              vec4, "pos");

   nir_variable *pos_out = nir_variable_create(b.shader, nir_var_shader_out,
                                               vec4, "gl_Position");
   pos_out->data.location = VARYING_SLOT_POS;

   nir_store_var(&b, pos_out, nir_load_var(&b, pos_in), 0xf);

   struct pipe_shader_state state = {};
   state.type = PIPE_SHADER_IR_NIR;
   state.ir.nir = b.shader;
   ctx->stencil_resolve_vs = ctx->base.create_vs_state(&ctx->base, &state);

   return ctx->stencil_resolve_vs;
}

static void *
get_stencil_resolve_fs(struct d3d12_context *ctx, bool no_flip)
{
   if (!no_flip && ctx->stencil_resolve_fs)
      return ctx->stencil_resolve_fs;

   if (no_flip && ctx->stencil_resolve_fs_no_flip)
      return ctx->stencil_resolve_fs_no_flip;

   nir_builder b = nir_builder_init_simple_shader(MESA_SHADER_FRAGMENT,
                                                  dxil_get_nir_compiler_options(),
                                                  no_flip ? "stencil_resolve_fs_no_flip" : "stencil_resolve_fs");

   nir_variable *stencil_out = nir_variable_create(b.shader,
                                                   nir_var_shader_out,
                                                   glsl_uint_type(),
                                                   "stencil_out");
   stencil_out->data.location = FRAG_RESULT_COLOR;

   const struct glsl_type *sampler_type =
      glsl_sampler_type(GLSL_SAMPLER_DIM_MS, false, false, GLSL_TYPE_UINT);
   nir_variable *sampler = nir_variable_create(b.shader, nir_var_uniform,
                                               sampler_type, "stencil_tex");
   sampler->data.binding = 0;
   sampler->data.explicit_binding = true;

   nir_ssa_def *tex_deref = &nir_build_deref_var(&b, sampler)->dest.ssa;

   nir_variable *pos_in = nir_variable_create(b.shader, nir_var_shader_in,
                                              glsl_vec4_type(), "pos");
   pos_in->data.location = VARYING_SLOT_POS; // VARYING_SLOT_VAR0?
   nir_ssa_def *pos = nir_load_var(&b, pos_in);

   nir_ssa_def *pos_src;

   if (no_flip)
      pos_src = pos;
   else {
      nir_tex_instr *txs = nir_tex_instr_create(b.shader, 1);
      txs->op = nir_texop_txs;
      txs->sampler_dim = GLSL_SAMPLER_DIM_MS;
      txs->src[0].src_type = nir_tex_src_texture_deref;
      txs->src[0].src = nir_src_for_ssa(tex_deref);
      txs->is_array = false;
      txs->dest_type = nir_type_int;

      nir_ssa_dest_init(&txs->instr, &txs->dest, 2, 32, "tex");
      nir_builder_instr_insert(&b, &txs->instr);

      pos_src = nir_vec4(&b,
                         nir_channel(&b, pos, 0),
                         /*Height - pos_dest.y - 1*/
                         nir_fsub(&b,
                                  nir_fsub(&b,
                                           nir_channel(&b, nir_i2f32(&b, &txs->dest.ssa), 1),
                                           nir_channel(&b, pos, 1)),
                                  nir_imm_float(&b, 1.0)),
                         nir_channel(&b, pos, 2),
                         nir_channel(&b, pos, 3));
   }

   nir_tex_instr *tex = nir_tex_instr_create(b.shader, 3);
   tex->sampler_dim = GLSL_SAMPLER_DIM_MS;
   tex->op = nir_texop_txf_ms;
   tex->src[0].src_type = nir_tex_src_coord;
   tex->src[0].src = nir_src_for_ssa(nir_channels(&b, nir_f2i32(&b, pos_src), 0x3));
   tex->src[1].src_type = nir_tex_src_ms_index;
   tex->src[1].src = nir_src_for_ssa(nir_imm_int(&b, 0)); /* just use first sample */
   tex->src[2].src_type = nir_tex_src_texture_deref;
   tex->src[2].src = nir_src_for_ssa(tex_deref);
   tex->dest_type = nir_type_uint32;
   tex->is_array = false;
   tex->coord_components = 2;

   nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, "tex");
   nir_builder_instr_insert(&b, &tex->instr);

   nir_store_var(&b, stencil_out, nir_channel(&b, &tex->dest.ssa, 1), 0x1);

   struct pipe_shader_state state = {};
   state.type = PIPE_SHADER_IR_NIR;
   state.ir.nir = b.shader;
   void *result;
   if (no_flip) {
      result = ctx->base.create_fs_state(&ctx->base, &state);
      ctx->stencil_resolve_fs_no_flip = result;
   } else {
      result = ctx->base.create_fs_state(&ctx->base, &state);
      ctx->stencil_resolve_fs = result;
   }

   return result;
}

static void *
get_sampler_state(struct d3d12_context *ctx)
{
   if (ctx->sampler_state)
      return ctx->sampler_state;

   struct pipe_sampler_state state;
   memset(&state, 0, sizeof(state));
   state.wrap_s = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
   state.wrap_t = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
   state.wrap_r = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
   state.normalized_coords = 1;

   return ctx->sampler_state = ctx->base.create_sampler_state(&ctx->base, &state);
}

static struct pipe_resource *
resolve_stencil_to_temp(struct d3d12_context *ctx,
                        const struct pipe_blit_info *info)
{
   struct pipe_context *pctx = &ctx->base;
   struct pipe_resource *tmp = create_tmp_resource(pctx->screen, info);
   if (!tmp) {
      debug_printf("D3D12: failed to create stencil-resolve temp-resource\n");
      return NULL;
   }
   assert(tmp->nr_samples < 2);

   /* resolve stencil into tmp */
   struct pipe_surface dst_tmpl;
   util_blitter_default_dst_texture(&dst_tmpl, tmp, 0, 0);
   dst_tmpl.format = tmp->format;
   struct pipe_surface *dst_surf = pctx->create_surface(pctx, tmp, &dst_tmpl);
   if (!dst_surf) {
      debug_printf("D3D12: failed to create stencil-resolve dst-surface\n");
      return NULL;
   }

   struct pipe_sampler_view src_templ, *src_view;
   util_blitter_default_src_texture(ctx->blitter, &src_templ,
                                    info->src.resource, info->src.level);
   src_templ.format = util_format_stencil_only(info->src.format);
   src_view = pctx->create_sampler_view(pctx, info->src.resource, &src_templ);

   void *sampler_state = get_sampler_state(ctx);

   util_blit_save_state(ctx);
   pctx->set_sampler_views(pctx, PIPE_SHADER_FRAGMENT, 0, 1, 0, false, &src_view);
   pctx->bind_sampler_states(pctx, PIPE_SHADER_FRAGMENT, 0, 1, &sampler_state);
   util_blitter_custom_shader(ctx->blitter, dst_surf,
                              get_stencil_resolve_vs(ctx),
                              get_stencil_resolve_fs(ctx, info->src.box.height == info->dst.box.height));
   util_blitter_restore_textures(ctx->blitter);
   pipe_surface_reference(&dst_surf, NULL);
   pipe_sampler_view_reference(&src_view, NULL);
   return tmp;
}

static void
blit_resolve_stencil(struct d3d12_context *ctx,
                     const struct pipe_blit_info *info)
{
   assert(info->mask & PIPE_MASK_S);

   if (D3D12_DEBUG_BLIT & d3d12_debug)
      debug_printf("D3D12 BLIT: blit_resolve_stencil\n");

   if (info->mask & PIPE_MASK_Z) {
      /* resolve depth into dst */
      struct pipe_blit_info new_info = *info;
      new_info.mask = PIPE_MASK_Z;

      if (resolve_supported(&new_info))
         blit_resolve(ctx, &new_info);
      else
         util_blit(ctx, &new_info);
   }

   struct pipe_resource *tmp = resolve_stencil_to_temp(ctx, info);


   /* copy resolved stencil into dst */
   struct d3d12_resource *dst = d3d12_resource(info->dst.resource);
   d3d12_transition_subresources_state(ctx, d3d12_resource(tmp),
                                       0, 1, 0, 1, 0, 1,
                                       D3D12_RESOURCE_STATE_COPY_SOURCE,
                                       D3D12_BIND_INVALIDATE_NONE);
   d3d12_transition_subresources_state(ctx, dst,
                                       0, 1, 0, 1, 1, 1,
                                       D3D12_RESOURCE_STATE_COPY_DEST,
                                       D3D12_BIND_INVALIDATE_FULL);
   d3d12_apply_resource_states(ctx);

   struct d3d12_batch *batch = d3d12_current_batch(ctx);
   d3d12_batch_reference_resource(batch, d3d12_resource(tmp));
   d3d12_batch_reference_resource(batch, dst);

   D3D12_BOX src_box;
   src_box.left = src_box.top = src_box.front = 0;
   src_box.right = tmp->width0;
   src_box.bottom = tmp->height0;
   src_box.back = tmp->depth0;

   D3D12_TEXTURE_COPY_LOCATION src_loc;
   src_loc.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
   src_loc.SubresourceIndex = 0;
   src_loc.pResource = d3d12_resource_resource(d3d12_resource(tmp));

   D3D12_TEXTURE_COPY_LOCATION dst_loc;
   dst_loc.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
   dst_loc.SubresourceIndex = 1;
   dst_loc.pResource = d3d12_resource_resource(dst);

   ctx->cmdlist->CopyTextureRegion(&dst_loc, info->dst.box.x,
                                   info->dst.box.y, info->dst.box.z,
                                   &src_loc, &src_box);

   pipe_resource_reference(&tmp, NULL);
}

static bool
replicate_stencil_supported(struct d3d12_context *ctx,
                            const struct pipe_blit_info *info)
{
   if (!util_format_is_depth_or_stencil(info->src.format) ||
       !(info->mask & PIPE_MASK_S))
      return false;

   if (info->mask & PIPE_MASK_Z) {
      struct pipe_blit_info new_info = *info;
      new_info.mask = PIPE_MASK_Z;
      if (!util_blitter_is_blit_supported(ctx->blitter, &new_info))
         return false;
   }

   return true;
}

static void
blit_replicate_stencil(struct d3d12_context *ctx,
                       const struct pipe_blit_info *info)
{
   assert(info->mask & PIPE_MASK_S);

   if (D3D12_DEBUG_BLIT & d3d12_debug)
      debug_printf("D3D12 BLIT: blit_replicate_stencil\n");

   if (info->mask & PIPE_MASK_Z) {
      /* resolve depth into dst */
      struct pipe_blit_info new_info = *info;
      new_info.mask = PIPE_MASK_Z;
      util_blit(ctx, &new_info);
   }

   util_blit_save_state(ctx);
   util_blitter_stencil_fallback(ctx->blitter, info->dst.resource,
                                 info->dst.level,
                                 &info->dst.box,
                                 info->src.resource,
                                 info->src.level,
                                 &info->src.box,
                                 info->scissor_enable ? &info->scissor : NULL);
}

void
d3d12_blit(struct pipe_context *pctx,
           const struct pipe_blit_info *info)
{
   struct d3d12_context *ctx = d3d12_context(pctx);

   if (!info->render_condition_enable && ctx->current_predication) {
      if (D3D12_DEBUG_BLIT & d3d12_debug)
         debug_printf("D3D12 BLIT: Disable predication\n");
      ctx->cmdlist->SetPredication(nullptr, 0, D3D12_PREDICATION_OP_EQUAL_ZERO);
   }

   if (D3D12_DEBUG_BLIT & d3d12_debug) {
      debug_printf("D3D12 BLIT: from %s@%d msaa:%d %dx%dx%d + %dx%dx%d\n",
                   util_format_name(info->src.format), info->src.level,
                   info->src.resource->nr_samples,
                   info->src.box.x, info->src.box.y, info->src.box.z,
                   info->src.box.width, info->src.box.height, info->src.box.depth);
      debug_printf("            to   %s@%d msaa:%d %dx%dx%d + %dx%dx%d ",
                   util_format_name(info->dst.format), info->dst.level,
                   info->dst.resource->nr_samples,
                   info->dst.box.x, info->dst.box.y, info->dst.box.z,
                   info->dst.box.width, info->dst.box.height, info->dst.box.depth);
      debug_printf("| flags %s%s%s\n",
                   info->render_condition_enable ? "cond " : "",
                   info->scissor_enable ? "scissor " : "",
                   info->alpha_blend ? "blend" : "");
   }

   if (is_same_resource(info))
      blit_same_resource(ctx, info);
   else if (is_resolve(info)) {
      if (resolve_supported(info))
         blit_resolve(ctx, info);
      else if (util_blitter_is_blit_supported(ctx->blitter, info))
         util_blit(ctx, info);
      else if (resolve_stencil_supported(ctx, info))
         blit_resolve_stencil(ctx, info);
      else
         debug_printf("D3D12: resolve unsupported %s -> %s\n",
                    util_format_short_name(info->src.resource->format),
                    util_format_short_name(info->dst.resource->format));
   } else if (direct_copy_supported(d3d12_screen(pctx->screen), info,
                                    ctx->current_predication != nullptr))
      d3d12_direct_copy(ctx, d3d12_resource(info->dst.resource),
                        info->dst.level, &info->dst.box,
                        d3d12_resource(info->src.resource),
                        info->src.level, &info->src.box, info->mask);
   else if (util_blitter_is_blit_supported(ctx->blitter, info))
      util_blit(ctx, info);
   else if (replicate_stencil_supported(ctx, info))
      blit_replicate_stencil(ctx, info);
   else
      debug_printf("D3D12: blit unsupported %s -> %s\n",
                 util_format_short_name(info->src.resource->format),
                 util_format_short_name(info->dst.resource->format));

   if (!info->render_condition_enable && ctx->current_predication) {
      ctx->cmdlist->SetPredication(
               d3d12_resource_resource(ctx->current_predication), 0, D3D12_PREDICATION_OP_EQUAL_ZERO);
      if (D3D12_DEBUG_BLIT & d3d12_debug)
         debug_printf("D3D12 BLIT: Re-enable predication\n");
   }

}

static void
d3d12_resource_copy_region(struct pipe_context *pctx,
                           struct pipe_resource *pdst,
                           unsigned dst_level,
                           unsigned dstx, unsigned dsty, unsigned dstz,
                           struct pipe_resource *psrc,
                           unsigned src_level,
                           const struct pipe_box *psrc_box)
{
   struct d3d12_context *ctx = d3d12_context(pctx);
   struct d3d12_resource *dst = d3d12_resource(pdst);
   struct d3d12_resource *src = d3d12_resource(psrc);
   struct pipe_resource *staging_res = NULL;
   const struct pipe_box *src_box = psrc_box;
   struct pipe_box staging_box, dst_box;

   if (D3D12_DEBUG_BLIT & d3d12_debug) {
      debug_printf("D3D12 COPY: from %s@%d msaa:%d mips:%d %dx%dx%d + %dx%dx%d\n",
                   util_format_name(psrc->format), src_level, psrc->nr_samples,
                   psrc->last_level,
                   psrc_box->x, psrc_box->y, psrc_box->z,
                   psrc_box->width, psrc_box->height, psrc_box->depth);
      debug_printf("            to   %s@%d msaa:%d mips:%d %dx%dx%d\n",
                   util_format_name(pdst->format), dst_level, psrc->nr_samples,
                   psrc->last_level, dstx, dsty, dstz);
   }

   /* Use an intermediate resource if copying from/to the same subresource */
   if (d3d12_resource_resource(dst) == d3d12_resource_resource(src) && dst_level == src_level) {
      staging_res = create_staging_resource(ctx, src, src_level, psrc_box, &staging_box, PIPE_MASK_RGBAZS);
      src = d3d12_resource(staging_res);
      src_level = 0;
      src_box = &staging_box;
   }

   dst_box.x = dstx;
   dst_box.y = dsty;
   dst_box.z = dstz;
   dst_box.width = psrc_box->width;
   dst_box.height = psrc_box->height;

   d3d12_direct_copy(ctx, dst, dst_level, &dst_box,
                     src, src_level, src_box, PIPE_MASK_RGBAZS);

   if (staging_res)
      pipe_resource_reference(&staging_res, NULL);
}

void
d3d12_context_blit_init(struct pipe_context *ctx)
{
   ctx->resource_copy_region = d3d12_resource_copy_region;
   ctx->blit = d3d12_blit;
}