specialcase02.c

来自「WinCE 3.0 BSP, 包含Inter SA1110, Intel_815」· C语言 代码 · 共 135 行

//
// Windows CE Software Graphics Library
// specialcase02.c
//
// Copyright (c) 2000 Microsoft Corporation. All rights reserved.
//
// This source file contains the implementations of the special case blitting
// routines that target 2Bpp surfaces.
//
// Currently, those routines are:
//
// SrcCopy0202
// SolidFill02
// SrcAnd0202
// SrcInvert0202
// SrcPaint0202
// Text02 (!TODO!)
// AlphaText02 (!TODO!)

#include "pch.h"
#include "swg.h"

// These helper arrays and functions are used by the templated functions.

static const BYTE LeftFillMask[] =
{
    0xff,
    0x3f,
    0x0f,
    0x03
};

static const BYTE RightFillMask[] =
{
    0xff,
    0xc0,
    0xf0,
    0xfc
};

static BYTE *
GetBltBuffer(
  LONG ByteCount
  );

// We can reuse the 2Bpp SD special case blit template for SRCCOPY, SRCAND,
// SRCPAINT, and SRCINVERT.

#define FUNCTION                     SrcCopy0202
#define BYTE_OP(D, S)                (S)
#define BLOCK_OP(pD, pS, ByteCount)  (memcpy((pD), (pS), (ByteCount)))

#include ".\templates\SD0202.h"

#undef FUNCTION
#undef BYTE_OP
#undef BLOCK_OP

#define FUNCTION                     SrcAnd0202
#define BYTE_OP(D, S)                ((D) & (S))
#define DWORD_OP(D, S)               ((D) & (S))

#include ".\templates\SD0202.h"

#undef FUNCTION
#undef BYTE_OP
#undef DWORD_OP

#define FUNCTION                     SrcPaint0202
#define BYTE_OP(D, S)                ((D) | (S))
#define DWORD_OP(D, S)               ((D) | (S))

#include ".\templates\SD0202.h"

#undef FUNCTION
#undef BYTE_OP
#undef DWORD_OP

#define FUNCTION                     SrcInvert0202
#define BYTE_OP(D, S)                ((D) ^ (S))
#define DWORD_OP(D, S)               ((D) ^ (S))

#include ".\templates\SD0202.h"

#undef FUNCTION
#undef BYTE_OP
#undef DWORD_OP

// Likewise, the special case 2Bpp PD blit template for PATFILL.

#define FUNCTION                     SolidFill02
#define BYTE_OP(D, P)                (P)
#define BLOCK_OP(pD, P, ByteCount)   (memset((pD), (P), (ByteCount)))

#include ".\templates\PDC02.h" 
 
#undef FUNCTION
#undef BYTE_OP
#undef BLOCK_OP

BYTE *
GetBltBuffer(
  LONG ByteCount
  )
{
  // GetBltBuffer
  // This function is called in order to allocate a temporary buffer for 
  // the blitting functuion to realign bit data. Need to allocate a buffer
  // large enough for one scanline (plus a  little spare).  Note that we
  // only realloc when a wider blt comes along.

  static DWORD * Buffer = NULL;
  static LONG    BufferSize = -1;

  if (ByteCount > BufferSize) {

    BufferSize = ByteCount;

    // Allocate the buffer DWORD-aligned, even though we
    // return it as a BYTE*.  This way callers may perform
    // DWORD-stride operations.

    LocalFree(Buffer);
    Buffer = LocalAlloc(LMEM_FIXED, ((ByteCount + 3) >> 2) * sizeof(DWORD));

    // If allocation failed, try again next time.

    if (Buffer == NULL) {
      BufferSize = -1;
    }
  }

  return (BYTE *)Buffer;
}