|
//定义SinCos函数： 同时计算sin(Angle)和cos(Angle)的内嵌x86汇编函数
void __declspec(naked) __stdcall SinCos(const double Angle,double& sina,double& cosa)
{
asm
{
fld qword ptr [esp+4]//Angle
mov eax,[esp+12]//&sina
mov edx,[esp+16]//&cosa
fsincos
fstp qword ptr [edx]
fstp qword ptr [eax]
ret 16
}
} |
3.用定点数代替浮点计算
void PicRotary2(const TPicRegion& Dst,const TPicRegion& Src,double RotaryAngle,double ZoomX,double ZoomY,double move_x,double move_y)
{
if ( (fabs(ZoomX*Src.width)<1.0e-4) || (fabs(ZoomY*Src.height)<1.0e-4) ) return; //太小的缩放比例认为已经不可见
double tmprZoomXY=1.0/(ZoomX*ZoomY);
double rZoomX=tmprZoomXY*ZoomY;
double rZoomY=tmprZoomXY*ZoomX;
double sinA,cosA;
SinCos(RotaryAngle,sinA,cosA);
long Ax_16=(long)(rZoomX*cosA*(1<<16));
long Ay_16=(long)(rZoomX*sinA*(1<<16));
long Bx_16=(long)(-rZoomY*sinA*(1<<16));
long By_16=(long)(rZoomY*cosA*(1<<16));
double rx0=Src.width*0.5; //(rx0,ry0)为旋转中心
double ry0=Src.height*0.5;
long Cx_16=(long)((-(rx0+move_x)*rZoomX*cosA+(ry0+move_y)*rZoomY*sinA+rx0)*(1<<16));
long Cy_16=(long)((-(rx0+move_x)*rZoomX*sinA-(ry0+move_y)*rZoomY*cosA+ry0)*(1<<16));
TARGB32* pDstLine=Dst.pdata;
long srcx0_16=(Cx_16);
long srcy0_16=(Cy_16);
for (long y=0;y
{
long srcx_16=srcx0_16;
long srcy_16=srcy0_16;
for (long x=0;x
{
long srcx=(srcx_16>>16);
long srcy=(srcy_16>>16);
if (PixelsIsInPic(Src,srcx,srcy))
pDstLine[x]=Pixels(Src,srcx,srcy);
srcx_16+=Ax_16;
srcy_16+=Ay_16;
}
srcx0_16+=Bx_16;
srcy0_16+=By_16;
((TUInt8*&)pDstLine)+=Dst.byte_width;
}
}
|
////////////////////////////////////////////////////////////////////////////////
//速度测试：
//==============================================================================
// PicRotary2 84.4 fps
////////////////////////////////////////////////////////////////////////////////
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 【责编:Kittoy】 |
