/*
 * Copyright 2015 Advanced Micro Devices, Inc.
 *
 * 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
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS 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 "state_tracker/st_context.h"
#include "state_tracker/st_cb_bitmap.h"
#include "state_tracker/st_cb_copyimage.h"
#include "state_tracker/st_cb_fbo.h"
#include "state_tracker/st_texture.h"

#include "util/u_box.h"
#include "util/u_format.h"
#include "util/u_inlines.h"


/**
 * Return an equivalent canonical format without "X" channels.
 *
 * Copying between incompatible formats is easier when the format is
 * canonicalized, meaning that it is in a standard form.
 *
 * The returned format has the same component sizes and swizzles as
 * the source format, the type is changed to UINT or UNORM, depending on
 * which one has the most swizzle combinations in their group.
 *
 * If it's not an array format, return a memcpy-equivalent array format.
 *
 * The key feature is that swizzled versions of formats of the same
 * component size always return the same component type.
 *
 * X returns A.
 * Luminance, intensity, alpha, depth, stencil, and 8-bit and 16-bit packed
 * formats are not supported. (same as ARB_copy_image)
 */
static enum pipe_format
get_canonical_format(enum pipe_format format)
{
   const struct util_format_description *desc =
      util_format_description(format);

   /* Packed formats. Return the equivalent array format. */
   if (format == PIPE_FORMAT_R11G11B10_FLOAT ||
       format == PIPE_FORMAT_R9G9B9E5_FLOAT)
      return get_canonical_format(PIPE_FORMAT_R8G8B8A8_UINT);

   if (desc->nr_channels == 4 &&
       desc->channel[0].size == 10 &&
       desc->channel[1].size == 10 &&
       desc->channel[2].size == 10 &&
       desc->channel[3].size == 2) {
      if (desc->swizzle[0] == PIPE_SWIZZLE_X &&
          desc->swizzle[1] == PIPE_SWIZZLE_Y &&
          desc->swizzle[2] == PIPE_SWIZZLE_Z)
         return get_canonical_format(PIPE_FORMAT_R8G8B8A8_UINT);

      return PIPE_FORMAT_NONE;
   }

#define RETURN_FOR_SWIZZLE1(x, format) \
   if (desc->swizzle[0] == PIPE_SWIZZLE_##x) \
      return format

#define RETURN_FOR_SWIZZLE2(x, y, format) \
   if (desc->swizzle[0] == PIPE_SWIZZLE_##x && \
       desc->swizzle[1] == PIPE_SWIZZLE_##y) \
      return format

#define RETURN_FOR_SWIZZLE3(x, y, z, format) \
   if (desc->swizzle[0] == PIPE_SWIZZLE_##x && \
       desc->swizzle[1] == PIPE_SWIZZLE_##y && \
       desc->swizzle[2] == PIPE_SWIZZLE_##z) \
      return format

#define RETURN_FOR_SWIZZLE4(x, y, z, w, format) \
   if (desc->swizzle[0] == PIPE_SWIZZLE_##x && \
       desc->swizzle[1] == PIPE_SWIZZLE_##y && \
       desc->swizzle[2] == PIPE_SWIZZLE_##z && \
       desc->swizzle[3] == PIPE_SWIZZLE_##w) \
      return format

   /* Array formats. */
   if (desc->is_array) {
      switch (desc->nr_channels) {
      case 1:
         switch (desc->channel[0].size) {
         case 8:
            RETURN_FOR_SWIZZLE1(X, PIPE_FORMAT_R8_UINT);
            break;

         case 16:
            RETURN_FOR_SWIZZLE1(X, PIPE_FORMAT_R16_UINT);
            break;

         case 32:
            RETURN_FOR_SWIZZLE1(X, PIPE_FORMAT_R32_UINT);
            break;
         }
         break;

      case 2:
         switch (desc->channel[0].size) {
         case 8:
            /* All formats in each group must be of the same type.
             * We can't use UINT for R8G8 while using UNORM for G8R8.
             */
            RETURN_FOR_SWIZZLE2(X, Y, PIPE_FORMAT_R8G8_UNORM);
            RETURN_FOR_SWIZZLE2(Y, X, PIPE_FORMAT_G8R8_UNORM);
            break;

         case 16:
            RETURN_FOR_SWIZZLE2(X, Y, PIPE_FORMAT_R16G16_UNORM);
            RETURN_FOR_SWIZZLE2(Y, X, PIPE_FORMAT_G16R16_UNORM);
            break;

         case 32:
            RETURN_FOR_SWIZZLE2(X, Y, PIPE_FORMAT_R32G32_UINT);
            break;
         }
         break;

      case 3:
         switch (desc->channel[0].size) {
         case 8:
            RETURN_FOR_SWIZZLE3(X, Y, Z, PIPE_FORMAT_R8G8B8_UINT);
            break;

         case 16:
            RETURN_FOR_SWIZZLE3(X, Y, Z, PIPE_FORMAT_R16G16B16_UINT);
            break;

         case 32:
            RETURN_FOR_SWIZZLE3(X, Y, Z, PIPE_FORMAT_R32G32B32_UINT);
            break;
         }
         break;

      case 4:
         switch (desc->channel[0].size) {
         case 8:
            RETURN_FOR_SWIZZLE4(X, Y, Z, W, PIPE_FORMAT_R8G8B8A8_UNORM);
            RETURN_FOR_SWIZZLE4(X, Y, Z, 1, PIPE_FORMAT_R8G8B8A8_UNORM);
            RETURN_FOR_SWIZZLE4(Z, Y, X, W, PIPE_FORMAT_B8G8R8A8_UNORM);
            RETURN_FOR_SWIZZLE4(Z, Y, X, 1, PIPE_FORMAT_B8G8R8A8_UNORM);
            RETURN_FOR_SWIZZLE4(W, Z, Y, X, PIPE_FORMAT_A8B8G8R8_UNORM);
            RETURN_FOR_SWIZZLE4(W, Z, Y, 1, PIPE_FORMAT_A8B8G8R8_UNORM);
            RETURN_FOR_SWIZZLE4(Y, Z, W, X, PIPE_FORMAT_A8R8G8B8_UNORM);
            RETURN_FOR_SWIZZLE4(Y, Z, W, 1, PIPE_FORMAT_A8R8G8B8_UNORM);
            break;

         case 16:
            RETURN_FOR_SWIZZLE4(X, Y, Z, W, PIPE_FORMAT_R16G16B16A16_UINT);
            RETURN_FOR_SWIZZLE4(X, Y, Z, 1, PIPE_FORMAT_R16G16B16A16_UINT);
            break;

         case 32:
            RETURN_FOR_SWIZZLE4(X, Y, Z, W, PIPE_FORMAT_R32G32B32A32_UINT);
            RETURN_FOR_SWIZZLE4(X, Y, Z, 1, PIPE_FORMAT_R32G32B32A32_UINT);
            break;
         }
      }

      assert(!"unknown array format");
      return PIPE_FORMAT_NONE;
   }

   assert(!"unknown packed format");
   return PIPE_FORMAT_NONE;
}

/**
 * Return true if the swizzle is XYZW in case of a 4-channel format,
 * XY in case of a 2-channel format, or X in case of a 1-channel format.
 */
static bool
has_identity_swizzle(const struct util_format_description *desc)
{
   int i;

   for (i = 0; i < desc->nr_channels; i++)
      if (desc->swizzle[i] != PIPE_SWIZZLE_X + i)
         return false;

   return true;
}

/**
 * Return a canonical format for the given bits and channel size.
 */
static enum pipe_format
canonical_format_from_bits(unsigned bits, unsigned channel_size)
{
   switch (bits) {
   case 8:
      if (channel_size == 8)
         return get_canonical_format(PIPE_FORMAT_R8_UINT);
      break;

   case 16:
      if (channel_size == 8)
         return get_canonical_format(PIPE_FORMAT_R8G8_UINT);
      if (channel_size == 16)
         return get_canonical_format(PIPE_FORMAT_R16_UINT);
      break;

   case 32:
      if (channel_size == 8)
         return get_canonical_format(PIPE_FORMAT_R8G8B8A8_UINT);
      if (channel_size == 16)
         return get_canonical_format(PIPE_FORMAT_R16G16_UINT);
      if (channel_size == 32)
         return get_canonical_format(PIPE_FORMAT_R32_UINT);
      break;

   case 64:
      if (channel_size == 16)
         return get_canonical_format(PIPE_FORMAT_R16G16B16A16_UINT);
      if (channel_size == 32)
         return get_canonical_format(PIPE_FORMAT_R32G32_UINT);
      break;

   case 128:
      if (channel_size == 32)
         return get_canonical_format(PIPE_FORMAT_R32G32B32A32_UINT);
      break;
   }

   assert(!"impossible format");
   return PIPE_FORMAT_NONE;
}

static void
blit(struct pipe_context *pipe,
     struct pipe_resource *dst,
     enum pipe_format dst_format,
     unsigned dst_level,
     unsigned dstx, unsigned dsty, unsigned dstz,
     struct pipe_resource *src,
     enum pipe_format src_format,
     unsigned src_level,
     const struct pipe_box *src_box)
{
   struct pipe_blit_info blit = {{0}};

   blit.src.resource = src;
   blit.dst.resource = dst;
   blit.src.format = src_format;
   blit.dst.format = dst_format;
   blit.src.level = src_level;
   blit.dst.level = dst_level;
   blit.src.box = *src_box;
   u_box_3d(dstx, dsty, dstz, src_box->width, src_box->height,
            src_box->depth, &blit.dst.box);
   blit.mask = PIPE_MASK_RGBA;
   blit.filter = PIPE_TEX_FILTER_NEAREST;

   pipe->blit(pipe, &blit);
}

static void
swizzled_copy(struct pipe_context *pipe,
              struct pipe_resource *dst,
              unsigned dst_level,
              unsigned dstx, unsigned dsty, unsigned dstz,
              struct pipe_resource *src,
              unsigned src_level,
              const struct pipe_box *src_box)
{
   const struct util_format_description *src_desc, *dst_desc;
   unsigned bits;
   enum pipe_format blit_src_format, blit_dst_format;

   /* Get equivalent canonical formats. Those are always array formats and
    * copying between compatible canonical formats behaves either like
    * memcpy or like swizzled memcpy. The idea is that we won't have to care
    * about the channel type from this point on.
    * Only the swizzle and channel size.
    */
   blit_src_format = get_canonical_format(src->format);
   blit_dst_format = get_canonical_format(dst->format);

   assert(blit_src_format != PIPE_FORMAT_NONE);
   assert(blit_dst_format != PIPE_FORMAT_NONE);

   src_desc = util_format_description(blit_src_format);
   dst_desc = util_format_description(blit_dst_format);

   assert(src_desc->block.bits == dst_desc->block.bits);
   bits = src_desc->block.bits;

   if (dst_desc->channel[0].size == src_desc->channel[0].size) {
      /* Only the swizzle is different, which means we can just blit,
       * e.g. RGBA -> BGRA.
       */
   } else if (has_identity_swizzle(src_desc)) {
      /* Src is unswizzled and dst can be swizzled, so src is typecast
       * to an equivalent dst-compatible format.
       * e.g. R32 -> BGRA8 is realized as RGBA8 -> BGRA8
       */
      blit_src_format =
         canonical_format_from_bits(bits, dst_desc->channel[0].size);
   } else if (has_identity_swizzle(dst_desc)) {
      /* Dst is unswizzled and src can be swizzled, so dst is typecast
       * to an equivalent src-compatible format.
       * e.g. BGRA8 -> R32 is realized as BGRA8 -> RGBA8
       */
      blit_dst_format =
         canonical_format_from_bits(bits, src_desc->channel[0].size);
   } else {
      assert(!"This should have been handled by handle_complex_copy.");
      return;
   }

   blit(pipe, dst, blit_dst_format, dst_level, dstx, dsty, dstz,
        src, blit_src_format, src_level, src_box);
}

static bool
same_size_and_swizzle(const struct util_format_description *d1,
                      const struct util_format_description *d2)
{
   int i;

   if (d1->layout != d2->layout ||
       d1->nr_channels != d2->nr_channels ||
       d1->is_array != d2->is_array)
      return false;

   for (i = 0; i < d1->nr_channels; i++) {
      if (d1->channel[i].size != d2->channel[i].size)
         return false;

      if (d1->swizzle[i] <= PIPE_SWIZZLE_W &&
          d2->swizzle[i] <= PIPE_SWIZZLE_W &&
          d1->swizzle[i] != d2->swizzle[i])
         return false;
   }

   return true;
}

static struct pipe_resource *
create_texture(struct pipe_screen *screen, enum pipe_format format,
               unsigned nr_samples,
               unsigned width, unsigned height, unsigned depth)
{
   struct pipe_resource templ;

   memset(&templ, 0, sizeof(templ));
   templ.format = format;
   templ.width0 = width;
   templ.height0 = height;
   templ.depth0 = 1;
   templ.array_size = depth;
   templ.nr_samples = nr_samples;
   templ.usage = PIPE_USAGE_DEFAULT;
   templ.bind = PIPE_BIND_SAMPLER_VIEW | PIPE_BIND_RENDER_TARGET;

   if (depth > 1)
      templ.target = PIPE_TEXTURE_2D_ARRAY;
   else
      templ.target = PIPE_TEXTURE_2D;

   return screen->resource_create(screen, &templ);
}

/**
 * Handle complex format conversions using 2 blits with a temporary texture
 * in between, e.g. blitting from B10G10R10A2 to G16R16.
 *
 * This example is implemented this way:
 * 1) First, blit from B10G10R10A2 to R10G10B10A2, which is canonical, so it
 *    can be reinterpreted as a different canonical format of the same bpp,
 *    such as R16G16. This blit only swaps R and B 10-bit components.
 * 2) Finally, blit the result, which is R10G10B10A2, as R16G16 to G16R16.
 *    This blit only swaps R and G 16-bit components.
 */
static bool
handle_complex_copy(struct pipe_context *pipe,
                    struct pipe_resource *dst,
                    unsigned dst_level,
                    unsigned dstx, unsigned dsty, unsigned dstz,
                    struct pipe_resource *src,
                    unsigned src_level,
                    const struct pipe_box *src_box,
                    enum pipe_format noncanon_format,
                    enum pipe_format canon_format)
{
   struct pipe_box temp_box;
   struct pipe_resource *temp = NULL;
   const struct util_format_description *src_desc, *dst_desc;
   const struct util_format_description *canon_desc, *noncanon_desc;
   bool src_is_canon;
   bool src_is_noncanon;
   bool dst_is_canon;
   bool dst_is_noncanon;

   src_desc = util_format_description(src->format);
   dst_desc = util_format_description(dst->format);
   canon_desc = util_format_description(canon_format);
   noncanon_desc = util_format_description(noncanon_format);

   src_is_canon = same_size_and_swizzle(src_desc, canon_desc);
   dst_is_canon = same_size_and_swizzle(dst_desc, canon_desc);
   src_is_noncanon = same_size_and_swizzle(src_desc, noncanon_desc);
   dst_is_noncanon = same_size_and_swizzle(dst_desc, noncanon_desc);

   if (src_is_noncanon) {
      /* Simple case - only types differ (e.g. UNORM and UINT). */
      if (dst_is_noncanon) {
         blit(pipe, dst, noncanon_format, dst_level, dstx, dsty, dstz, src,
              noncanon_format, src_level, src_box);
         return true;
      }

      /* Simple case - only types and swizzles differ. */
      if (dst_is_canon) {
         blit(pipe, dst, canon_format, dst_level, dstx, dsty, dstz, src,
              noncanon_format, src_level, src_box);
         return true;
      }

      /* Use the temporary texture. Src is converted to a canonical format,
       * then proceed the generic swizzled_copy.
       */
      temp = create_texture(pipe->screen, canon_format, src->nr_samples,
                            src_box->width,
                            src_box->height, src_box->depth);

      u_box_3d(0, 0, 0, src_box->width, src_box->height, src_box->depth,
               &temp_box);

      blit(pipe, temp, canon_format, 0, 0, 0, 0, src, noncanon_format,
           src_level, src_box);
      swizzled_copy(pipe, dst, dst_level, dstx, dsty, dstz, temp, 0,
                    &temp_box);
      pipe_resource_reference(&temp, NULL);
      return true;
   }

   if (dst_is_noncanon) {
      /* Simple case - only types and swizzles differ. */
      if (src_is_canon) {
         blit(pipe, dst, noncanon_format, dst_level, dstx, dsty, dstz, src,
              canon_format, src_level, src_box);
         return true;
      }

      /* Use the temporary texture. First, use the generic copy, but use
       * a canonical format in the destination. Then convert */
      temp = create_texture(pipe->screen, canon_format, dst->nr_samples,
                            src_box->width,
                            src_box->height, src_box->depth);

      u_box_3d(0, 0, 0, src_box->width, src_box->height, src_box->depth,
               &temp_box);

      swizzled_copy(pipe, temp, 0, 0, 0, 0, src, src_level, src_box);
      blit(pipe, dst, noncanon_format, dst_level, dstx, dsty, dstz, temp,
           canon_format, 0, &temp_box);
      pipe_resource_reference(&temp, NULL);
      return true;
   }

   return false;
}

static void
copy_image(struct pipe_context *pipe,
           struct pipe_resource *dst,
           unsigned dst_level,
           unsigned dstx, unsigned dsty, unsigned dstz,
           struct pipe_resource *src,
           unsigned src_level,
           const struct pipe_box *src_box)
{
   if (src->format == dst->format ||
       util_format_is_compressed(src->format) ||
       util_format_is_compressed(dst->format)) {
      pipe->resource_copy_region(pipe, dst, dst_level, dstx, dsty, dstz,
                                 src, src_level, src_box);
      return;
   }

   /* Copying to/from B10G10R10*2 needs 2 blits with R10G10B10A2
    * as a temporary texture in between.
    */
   if (handle_complex_copy(pipe, dst, dst_level, dstx, dsty, dstz, src,
                           src_level, src_box, PIPE_FORMAT_B10G10R10A2_UINT,
                           PIPE_FORMAT_R10G10B10A2_UINT))
      return;

   /* Copying to/from G8R8 needs 2 blits with R8G8 as a temporary texture
    * in between.
    */
   if (handle_complex_copy(pipe, dst, dst_level, dstx, dsty, dstz, src,
                           src_level, src_box, PIPE_FORMAT_G8R8_UNORM,
                           PIPE_FORMAT_R8G8_UNORM))
      return;

   /* Copying to/from G16R16 needs 2 blits with R16G16 as a temporary texture
    * in between.
    */
   if (handle_complex_copy(pipe, dst, dst_level, dstx, dsty, dstz, src,
                           src_level, src_box, PIPE_FORMAT_G16R16_UNORM,
                           PIPE_FORMAT_R16G16_UNORM))
      return;

   /* Only allow non-identity swizzling on RGBA8 formats. */

   /* Simple copy, memcpy with swizzling, no format conversion. */
   swizzled_copy(pipe, dst, dst_level, dstx, dsty, dstz, src, src_level,
                 src_box);
}

static void
st_CopyImageSubData(struct gl_context *ctx,
                    struct gl_texture_image *src_image,
                    struct gl_renderbuffer *src_renderbuffer,
                    int src_x, int src_y, int src_z,
                    struct gl_texture_image *dst_image,
                    struct gl_renderbuffer *dst_renderbuffer,
                    int dst_x, int dst_y, int dst_z,
                    int src_width, int src_height)
{
   struct st_context *st = st_context(ctx);
   struct pipe_context *pipe = st->pipe;
   struct pipe_resource *src_res, *dst_res;
   struct pipe_box box;
   int src_level, dst_level;

   st_flush_bitmap_cache(st);

   if (src_image) {
      struct st_texture_image *src = st_texture_image(src_image);
      src_res = src->pt;
      src_level = src_image->Level;
      src_z += src_image->Face;
      if (src_image->TexObject->Immutable) {
         src_level += src_image->TexObject->MinLevel;
         src_z += src_image->TexObject->MinLayer;
      }
   } else {
      struct st_renderbuffer *src = st_renderbuffer(src_renderbuffer);
      src_res = src->texture;
      src_level = 0;
   }

   if (dst_image) {
      struct st_texture_image *dst = st_texture_image(dst_image);
      dst_res = dst->pt;
      dst_level = dst_image->Level;
      dst_z += dst_image->Face;
      if (dst_image->TexObject->Immutable) {
         dst_level += dst_image->TexObject->MinLevel;
         dst_z += dst_image->TexObject->MinLayer;
      }
   } else {
      struct st_renderbuffer *dst = st_renderbuffer(dst_renderbuffer);
      dst_res = dst->texture;
      dst_level = 0;
   }

   u_box_2d_zslice(src_x, src_y, src_z, src_width, src_height, &box);

   copy_image(pipe, dst_res, dst_level, dst_x, dst_y, dst_z,
              src_res, src_level, &box);
}

void
st_init_copy_image_functions(struct dd_function_table *functions)
{
   functions->CopyImageSubData = st_CopyImageSubData;
}