32bpp_optimized.cpp

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/* $Id: 32bpp_optimized.cpp 13640 2008-06-26 16:47:29Z smatz $ */

#include "../stdafx.h"
#include "../zoom_func.h"
#include "../gfx_func.h"
#include "../debug.h"
#include "../core/math_func.hpp"
#include "../core/alloc_func.hpp"
#include "32bpp_optimized.hpp"

static FBlitter_32bppOptimized iFBlitter_32bppOptimized;

template <BlitterMode mode>
inline void Blitter_32bppOptimized::Draw(const Blitter::BlitterParams *bp, ZoomLevel zoom)
{
  const SpriteData *src = (const SpriteData *)bp->sprite;

  /* src_px : each line begins with uint32 n = 'number of bytes in this line',
   *          then n times is the Colour struct for this line */
  const Colour *src_px = (const Colour *)(src->data + src->offset[zoom][0]);
  /* src_n  : each line begins with uint32 n = 'number of bytes in this line',
   *          then interleaved stream of 'm' and 'n' channels. 'm' is remap,
   *          'n' is number of bytes with the same alpha channel class */
  const uint8  *src_n  = (const uint8  *)(src->data + src->offset[zoom][1]);

  /* skip upper lines in src_px and src_n */
  for (uint i = bp->skip_top; i != 0; i--) {
    src_px = (const Colour *)((const byte *)src_px + *(const uint32 *)src_px);
    src_n += *(uint32 *)src_n;
  }

  /* skip lines in dst */
  uint32 *dst = (uint32 *)bp->dst + bp->top * bp->pitch + bp->left;

  /* store so we don't have to access it via bp everytime (compiler assumes pointer aliasing) */
  const byte *remap = bp->remap;

  for (int y = 0; y < bp->height; y++) {
    /* next dst line begins here */
    uint32 *dst_ln = dst + bp->pitch;

    /* next src line begins here */
    const Colour *src_px_ln = (const Colour *)((const byte *)src_px + *(const uint32 *)src_px);
    src_px++;

    /* next src_n line begins here */
    const uint8 *src_n_ln = src_n + *(uint32 *)src_n;
    src_n += 4;

    /* we will end this line when we reach this point */
    uint32 *dst_end = dst + bp->skip_left;

    /* number of pixels with the same aplha channel class */
    uint n;

    while (dst < dst_end) {
      n = *src_n++;

      if (src_px->a == 0) {
        dst += n;
        src_px ++;
        src_n++;
      } else {
        if (dst + n > dst_end) {
          uint d = dst_end - dst;
          src_px += d;
          src_n += d;

          dst = dst_end - bp->skip_left;
          dst_end = dst + bp->width;

          n = min<uint>(n - d, (uint)bp->width);
          goto draw;
        }
        dst += n;
        src_px += n;
        src_n += n;
      }
    }

    dst -= bp->skip_left;
    dst_end -= bp->skip_left;

    dst_end += bp->width;

    while (dst < dst_end) {
      n = min<uint>(*src_n++, (uint)(dst_end - dst));

      if (src_px->a == 0) {
        dst += n;
        src_px++;
        src_n++;
        continue;
      }

      draw:;

      switch (mode) {
        case BM_COLOUR_REMAP:
          if (src_px->a == 255) {
            do {
              uint m = *src_n;
              /* In case the m-channel is zero, do not remap this pixel in any way */
              if (m == 0) {
                *dst = *src_px;
              } else {
                uint r = remap[m];
                if (r != 0) *dst = this->LookupColourInPalette(r);
              }
              dst++;
              src_px++;
              src_n++;
            } while (--n != 0);
          } else {
            do {
              uint m = *src_n;
              if (m == 0) {
                *dst = ComposeColourRGBANoCheck(src_px->r, src_px->g, src_px->b, src_px->a, *dst);
              } else {
                uint r = remap[m];
                if (r != 0) *dst = ComposeColourPANoCheck(this->LookupColourInPalette(r), src_px->a, *dst);
              }
              dst++;
              src_px++;
              src_n++;
            } while (--n != 0);
          }
          break;

        case BM_TRANSPARENT:
          /* TODO -- We make an assumption here that the remap in fact is transparency, not some color.
           *  This is never a problem with the code we produce, but newgrfs can make it fail... or at least:
           *  we produce a result the newgrf maker didn't expect ;) */

          /* Make the current color a bit more black, so it looks like this image is transparent */
          src_n += n;
          if (src_px->a == 255) {
            src_px += n;
            do {
              *dst = MakeTransparent(*dst, 3, 4);
              dst++;
            } while (--n != 0);
          } else {
            do {
              *dst = MakeTransparent(*dst, (256 * 4 - src_px->a), 256 * 4);
              dst++;
              src_px++;
            } while (--n != 0);
          }
          break;

        default:
          if (src_px->a == 255) {
            /* faster than memcpy(), n is usually low */
            src_n += n;
            do {
              *dst++ = *src_px++;
            } while (--n != 0);
          } else {
            src_n += n;
            do {
              *dst = ComposeColourRGBANoCheck(src_px->r, src_px->g, src_px->b, src_px->a, *dst);
              dst++;
              src_px++;
            } while (--n != 0);
          }
          break;
      }
    }

    dst = dst_ln;
    src_px = src_px_ln;
    src_n  = src_n_ln;
  }
}

void Blitter_32bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
{
  switch (mode) {
    default: NOT_REACHED();
    case BM_NORMAL:       Draw<BM_NORMAL>      (bp, zoom); return;
    case BM_COLOUR_REMAP: Draw<BM_COLOUR_REMAP>(bp, zoom); return;
    case BM_TRANSPARENT:  Draw<BM_TRANSPARENT> (bp, zoom); return;
  }
}

static const SpriteLoader::Sprite *ResizeSprite(const SpriteLoader::Sprite *sprite_src, ZoomLevel zoom)
{
  SpriteLoader::Sprite *sprite = MallocT<SpriteLoader::Sprite>(1);

  if (zoom == ZOOM_LVL_NORMAL) {
    memcpy(sprite, sprite_src, sizeof(*sprite));
    uint size = sprite_src->height * sprite_src->width;
    sprite->data = MallocT<SpriteLoader::CommonPixel>(size);
    memcpy(sprite->data, sprite_src->data, size * sizeof(SpriteLoader::CommonPixel));
    return sprite;
  }

  sprite->height = UnScaleByZoom(sprite_src->height, zoom);
  sprite->width  = UnScaleByZoom(sprite_src->width,  zoom);
  sprite->x_offs = UnScaleByZoom(sprite_src->x_offs, zoom);
  sprite->y_offs = UnScaleByZoom(sprite_src->y_offs, zoom);

  uint size = sprite->height * sprite->width;
  SpriteLoader::CommonPixel *dst = sprite->data = CallocT<SpriteLoader::CommonPixel>(size);

  const SpriteLoader::CommonPixel *src = (SpriteLoader::CommonPixel *)sprite_src->data;
  const SpriteLoader::CommonPixel *src_end = src + sprite_src->height * sprite_src->width;

  uint scaled_1 = ScaleByZoom(1, zoom);

  for (uint y = 0; y < sprite->height; y++) {
    if (src >= src_end) src = src_end - sprite_src->width;

    const SpriteLoader::CommonPixel *src_ln = src + sprite_src->width * scaled_1;
    for (uint x = 0; x < sprite->width; x++) {
      if (src >= src_ln) src = src_ln - 1;
      *dst = *src;
      dst++;
      src += scaled_1;
    }

    src = src_ln;
  }

  return sprite;
}

Sprite *Blitter_32bppOptimized::Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator)
{
  /* streams of pixels (a, r, g, b channels)
   *
   * stored in separated stream so data are always aligned on 4B boundary */
  Colour *dst_px_orig[ZOOM_LVL_COUNT];

  /* interleaved stream of 'm' channel and 'n' channel
   * 'n' is number if following pixels with the same alpha channel class
   * there are 3 classes: 0, 255, others
   *
   * it has to be stored in one stream so fewer registers are used -
   * x86 has problems with register allocation even with this solution */
  uint8  *dst_n_orig[ZOOM_LVL_COUNT];

  /* lengths of streams */
  uint32 lengths[ZOOM_LVL_COUNT][2];

  for (ZoomLevel z = ZOOM_LVL_BEGIN; z < ZOOM_LVL_END; z++) {
    const SpriteLoader::Sprite *src_orig = ResizeSprite(sprite, z);

    uint size = src_orig->height * src_orig->width;

    dst_px_orig[z] = CallocT<Colour>(size + src_orig->height * 2);
    dst_n_orig[z]  = CallocT<uint8>(size * 2 + src_orig->height * 4 * 2);

    uint32 *dst_px_ln = (uint32 *)dst_px_orig[z];
    uint32 *dst_n_ln  = (uint32 *)dst_n_orig[z];

    const SpriteLoader::CommonPixel *src = (const SpriteLoader::CommonPixel *)src_orig->data;

    for (uint y = src_orig->height; y > 0; y--) {
      Colour *dst_px = (Colour *)(dst_px_ln + 1);
      uint8 *dst_n = (uint8 *)(dst_n_ln + 1);

      uint8 *dst_len = dst_n++;

      uint last = 3;
      int len = 0;

      for (uint x = src_orig->width; x > 0; x--) {
        uint8 a = src->a;
        uint t = a > 0 && a < 255 ? 1 : a;

        if (last != t || len == 255) {
          if (last != 3) {
            *dst_len = len;
            dst_len = dst_n++;
          }
          len = 0;
        }

        last = t;
        len++;

        if (a != 0) {
          dst_px->a = a;
          *dst_n = src->m;
          if (src->m != 0) {
            /* Pre-convert the mapping channel to a RGB value */
            uint32 colour = this->LookupColourInPalette(src->m);
            dst_px->r = GB(colour, 16, 8);
            dst_px->g = GB(colour, 8,  8);
            dst_px->b = GB(colour, 0,  8);
          } else {
            dst_px->r = src->r;
            dst_px->g = src->g;
            dst_px->b = src->b;
          }
          dst_px++;
          dst_n++;
        } else if (len == 1) {
          dst_px++;
          *dst_n = src->m;
          dst_n++;
        }

        src++;
      }

      if (last != 3) {
        *dst_len = len;
      }

      dst_px = (Colour *)AlignPtr(dst_px, 4);
      dst_n  = (uint8 *)AlignPtr(dst_n, 4);

      *dst_px_ln = (uint8 *)dst_px - (uint8 *)dst_px_ln;
      *dst_n_ln  = (uint8 *)dst_n  - (uint8 *)dst_n_ln;

      dst_px_ln = (uint32 *)dst_px;
      dst_n_ln =  (uint32 *)dst_n;
    }

    lengths[z][0] = (byte *)dst_px_ln - (byte *)dst_px_orig[z]; // all are aligned to 4B boundary
    lengths[z][1] = (byte *)dst_n_ln  - (byte *)dst_n_orig[z];

    free(src_orig->data);
    free((void *)src_orig);
  }

  uint len = 0; // total length of data
  for (ZoomLevel z = ZOOM_LVL_BEGIN; z < ZOOM_LVL_END; z++) {
    len += lengths[z][0] + lengths[z][1];
  }

  Sprite *dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + sizeof(SpriteData) + len);

  dest_sprite->height = sprite->height;
  dest_sprite->width  = sprite->width;
  dest_sprite->x_offs = sprite->x_offs;
  dest_sprite->y_offs = sprite->y_offs;

  SpriteData *dst = (SpriteData *)dest_sprite->data;

  for (ZoomLevel z = ZOOM_LVL_BEGIN; z < ZOOM_LVL_END; z++) {
    dst->offset[z][0] = z == ZOOM_LVL_BEGIN ? 0 : lengths[z - 1][1] + dst->offset[z - 1][1];
    dst->offset[z][1] = lengths[z][0] + dst->offset[z][0];

    memcpy(dst->data + dst->offset[z][0], dst_px_orig[z], lengths[z][0]);
    memcpy(dst->data + dst->offset[z][1], dst_n_orig[z],  lengths[z][1]);

    free(dst_px_orig[z]);
    free(dst_n_orig[z]);
  }

  return dest_sprite;
}