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Subject: AAFont精度采样 [Print This Page]

Author: croslq Time: 2005-10-18 08:59 Subject: AAFont精度采样

zjy，你的字体精度采样哪段的确做得好。
下面一段
  BytesLineGray := (GrayBmp.Width + 3) div 4 * 4; //扫描线宽度
  BytesLineMask := (FMaskPathBmp.Width + 3) div 4 * 4;

  pS1 := GrayBmp.ScanLine[0];          //源灰度图
  pS2 := PByteArray(Integer(pS1) - BytesLineGray);
  pS3 := PByteArray(Integer(pS2) - BytesLineGray);
  pS4 := PByteArray(Integer(pS3) - BytesLineGray);
  pDes := FMaskPathBmp.ScanLine[0];
//  pDes := PByteArray(Integer(FMaskBmp.scanLine[0]) + (FMaskBmp.Height - 1) * BytesLineMask);
//目标灰度为源矩形块的平均值
  case Quality of
aqHigh:
   begin                            //高精度4X4采样
      for i := 0 to FMaskPathBmp.Height - 1 do
      begin
      for j := 0 to FmaskPathBmp.Width - 1 do
      begin
         x := j * 4;
         pDes^[j] :=
            (pS1^[x] + pS1^[x + 1] + pS1^[x + 2] + pS1^[x + 3] +
            pS2^[x] + pS2^[x + 1] + pS2^[x + 2] + pS2^[x + 3] +
            pS3^[x] + pS3^[x + 1] + pS3^[x + 2] + pS3^[x + 3] +
            pS4^[x] + pS4^[x + 1] + pS4^[x + 2] + pS4^[x + 3]) shr 4;
      end;
      pS1 := PByteArray(Integer(pS4) - BytesLineGray);
      pS2 := PByteArray(Integer(pS1) - BytesLineGray);
      pS3 := PByteArray(Integer(pS2) - BytesLineGray);
      pS4 := PByteArray(Integer(pS3) - BytesLineGray);
      pDes := PByteArray(Integer(pDes) - BytesLineMask);
      end;
   end;
aqNormal:
   begin                            //普通精度3X3采样
      for i := 0 to FMaskPathBmp.Height - 1 do
      begin
      for j := 0 to FMaskPathBmp.Width - 1 do
      begin
         x := j * 3;
         pDes^[j] :=
            (pS1^[x] + pS1^[x + 1] + pS1^[x + 2] shr 1 +
            pS2^[x] + pS2^[x + 1] + pS2^[x + 2] +
            pS3^[x] shr 1 + pS3^[x + 1] + pS3^[x + 2]) shr 3;
      end;
      pS1 := PByteArray(Integer(pS3) - BytesLineGray);
      pS2 := PByteArray(Integer(pS1) - BytesLineGray);
      pS3 := PByteArray(Integer(pS2) - BytesLineGray);
      pDes := PByteArray(Integer(pDes) - BytesLineMask);
      end;
   end;
aqLow:
   begin                            //低精度2X2采样
      for i := 0 to FMaskPathBmp.Height - 1 do
      begin
      for j := 0 to FMaskPathBmp.Width - 1 do
      begin
         x := j * 2;
         pDes^[j] :=
            (pS1^[x] + pS1^[x + 1] +
            pS2^[x] + pS2^[x + 1]) shr 2;
      end;
      pS1 := PByteArray(Integer(pS2) - BytesLineGray);
      pS2 := PByteArray(Integer(pS1) - BytesLineGray);
      pDes := PByteArray(Integer(pDes) - BytesLineMask);
      end;
   end;
aqNone:
   begin                            //无平滑效果
      for i := 0 to FMaskPathBmp.Height - 1 do
      begin
      CopyMemory(pDes, pS1, FMaskPathBmp.Width);
      pS1 := PByteArray(Integer(pS1) - BytesLineGray);
      pDes := PByteArray(Integer(pDes) - BytesLineMask);
      end;
   end;
  end;

比起这段代码快多了。虽然下面这段代码更小，由于要在内循环内运行许多次加法除法运算，
速度要慢很多

for y := 0 to GrayBmp.Height Div Scale -1 do
begin
   DestScan := FMaskPathBmp.ScanLine[y];
   for x := 0 to GrayBmp.Width Div Scale -1 do
   begin
      tot := 0;

      for j := 0 to Scale - 1 do
      begin
      BigScan := pByteArray(GrayBmp.ScanLine[Scale * y + j] );
      for i := 0 to Scale -1 do
      begin
         tot := tot + BigScan[Scale * x+i];
      end;
      end;
      DestScan[x] := tot div (Scale * Scale);
   end;
end;

我找到一个MMX的，不过用你哪个也像是性能差不多

////////////////////////////////////////////////////////////////////////////////
// File:    PegtopResampleUtils.pas
// Version: 1.00
// Date:    16 Mar 2005 created 1.00
// Author:    Jens Gruschel (GRU)
// Copyright:  (c) 2005 Jens Gruschel
// Website: http://www.pegtop.net/delphi
////////////////////////////////////////////////////////////////////////////////
// Description:
// Procedures to resample bitmaps using MMX.
////////////////////////////////////////////////////////////////////////////////
// License:
// Please read the license.txt file that comes with this software
// and visit http://www.pegtop.net/delphi
////////////////////////////////////////////////////////////////////////////////
// Documentation / Installation:
// Please read the readme.txt file that comes with this software
// and visit http://www.pegtop.net/delphi
////////////////////////////////////////////////////////////////////////////////

unit PegtopResampleUtils;

interface

uses
  Windows;

// Bitmap resampling (without clipping):
procedure PegtopResample2x32MMX(const DestOrigin: Pointer; const DestPitch: Integer; const DestRect: TRect;
  const SourceOrigin: Pointer; const SourcePitch: Integer; const SourceX, SourceY: Integer);
procedure PegtopResample4x32MMX(const DestOrigin: Pointer; const DestPitch: Integer; const DestRect: TRect;
  const SourceOrigin: Pointer; const SourcePitch: Integer; const SourceX, SourceY: Integer);

implementation

////////////////////////////////////////////////////////////////////////////////
// Bitmap resampling (without clipping)
////////////////////////////////////////////////////////////////////////////////

procedure PegtopResample2x32MMX(const DestOrigin: Pointer; const DestPitch: Integer; const DestRect: TRect;
  const SourceOrigin: Pointer; const SourcePitch: Integer; const SourceX, SourceY: Integer);
var
  W, Y: Integer;
  DestQ: Pointer;
  SourceQ: Pointer;
begin
  DestQ := Pointer(Integer(DestOrigin) + DestRect.Top * DestPitch + DestRect.Left * 4);
  SourceQ := Pointer(Integer(SourceOrigin) + SourceY * SourcePitch + SourceX * 4);
  W := DestRect.Right - DestRect.Left;
  asm
// we need mm0 to be zero during the whole loop:
db $0F,$EF,$C0          /// pxor    mm0, mm0
  end;
  for Y := DestRect.Top to DestRect.Bottom - 1 do begin
asm
   mov    eax, SourceQ
   mov    edx, DestQ
   mov    ecx, W
   @xloop:
      // source pixels (0,0) and (1,0):
      db $0F,$6F,$08          /// movq    mm1, [eax]
      db $0F,$6F,$D1          /// movq    mm2, mm1
      db $0F,$60,$C8          /// punpcklbw mm1, mm0
      db $0F,$68,$D0          /// punpckhbw mm2, mm0
      db $0F,$DD,$CA          /// paddusw mm1, mm2
      // source pixels (0,1) and (1,1):
      add    eax, SourcePitch
      db $0F,$6F,$10          /// movq    mm2, [eax]
      db $0F,$6F,$DA          /// movq    mm3, mm2
      db $0F,$60,$D0          /// punpcklbw mm2, mm0
      db $0F,$68,$D8          /// punpckhbw mm3, mm0
      db $0F,$DD,$CA          /// paddusw mm1, mm2
      db $0F,$DD,$CB          /// paddusw mm1, mm3
      // set average color (divide by 4):
      db $0F,$71,$D1,$02    /// psrlw mm1, 2
      db $0F,$67,$C8          /// packuswb  mm1, mm0
      db $0F,$7E,$0A          /// movd    [edx], mm1
      // next source pixel block:
      sub    eax, SourcePitch
      add    eax, 8
      // next destination pixel:
      add    edx, 4
      dec ecx
   jnz @xloop
end;
DestQ := Pointer(Integer(DestQ) + DestPitch);
SourceQ := Pointer(Integer(SourceQ) + SourcePitch + SourcePitch);
  end;
  asm
// finish MMX usage:
db $0F,$77             /// emms
  end;
end;

procedure PegtopResample4x32MMX(const DestOrigin: Pointer; const DestPitch: Integer; const DestRect: TRect;
  const SourceOrigin: Pointer; const SourcePitch: Integer; const SourceX, SourceY: Integer);
var
  W, Y: Integer;
  DestQ: Pointer;
  SourceQ: Pointer;
  BlockStep: Integer;
begin
  DestQ := Pointer(Integer(DestOrigin) + DestRect.Top * DestPitch + DestRect.Left * 4);
  SourceQ := Pointer(Integer(SourceOrigin) + SourceY * SourcePitch + SourceX * 4);
  BlockStep := SourcePitch * 4 - 16;
  W := DestRect.Right - DestRect.Left;
  asm
// we need mm0 to be zero during the whole loop:
db $0F,$EF,$C0          /// pxor    mm0, mm0
  end;
  for Y := DestRect.Top to DestRect.Bottom - 1 do begin
asm
   mov    eax, SourceQ
   mov    edx, DestQ
   mov    ecx, W
   @xloop:
      push ecx
      db $0F,$EF,$C9          /// pxor    mm1, mm1
      // process 4 lines of source bitmap:
      mov ecx, 4
      @ploop:
      // source pixels (0,p) and (1,p):
      db $0F,$6F,$10          /// movq    mm2, [eax]
      db $0F,$6F,$DA          /// movq    mm3, mm2
      db $0F,$60,$D0          /// punpcklbw mm2, mm0
      db $0F,$68,$D8          /// punpckhbw mm3, mm0
      db $0F,$DD,$CA          /// paddusw mm1, mm2
      db $0F,$DD,$CB          /// paddusw mm1, mm3
      // source pixels (2,p) and (3,p):
      add    eax, 8
      db $0F,$6F,$10          /// movq    mm2, [eax]
      db $0F,$6F,$DA          /// movq    mm3, mm2
      db $0F,$60,$D0          /// punpcklbw mm2, mm0
      db $0F,$68,$D8          /// punpckhbw mm3, mm0
      db $0F,$DD,$CA          /// paddusw mm1, mm2
      db $0F,$DD,$CB          /// paddusw mm1, mm3
      // next source line:
      sub    eax, 8
      add    eax, SourcePitch
      dec ecx
      jnz @ploop
      // set average color (divide by 16):
      db $0F,$71,$D1,$04    /// psrlw mm1, 4
      db $0F,$67,$C8          /// packuswb  mm1, mm0
      db $0F,$7E,$0A          /// movd    [edx], mm1
      // next source pixel block:
      sub    eax, BlockStep
      // next destination pixel:
      add    edx, 4
      pop ecx
      dec ecx
   jnz @xloop
end;
DestQ := Pointer(Integer(DestQ) + DestPitch);
SourceQ := Pointer(Integer(SourceQ) + SourcePitch * 4);
  end;
  asm
// finish MMX usage:
db $0F,$77             /// emms
  end;
end;

end.

[ Last edited by croslq on 2005-10-18 at 09:06 ]

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