xleft

[C#]繪制函數圖像.可拖動,可縮放,可調整精度

欸嘿,這就是程序圖了,通過?標拖拽可以移動,?標滾輪可以縮放,右下?還可以選擇要繪制的函數.項?倉庫鏈接在?章末尾

基本原理:

Graphics繪圖,不?我說了吧?如果你不是很懂,留?,我會專門寫?篇?章來介紹Graphics.

帶?求值,沒啥難的.線是?個個點連起來的,也就是:

然后,標尺,也是?個個線唄,那個數字的話,就是這個:

填充?三?的話,就是這個:

關于優化:

?先是計算問題,保證僅僅計算需要顯?的區域,區域外的坐標不予以計算,以節省資源.

然后是閃屏問題,使?BufferedGraphics,既能解決閃屏問題,?不會像Bitmap緩沖那樣閃屏.

關于繪圖閃屏問題,?上有很多解決?案,最核?的,??是雙緩沖,也就是先將圖繪制到緩沖區,再將緩沖區的內容繪制到屏幕上.

實現雙緩沖有兩種?式,?就是通過創建?個Bitmap,將圖畫到Bitmap上,然后畫完之后,再將Bitmap畫到屏幕上

(age()),缺點是會造成撕裂問題.

第?種?式是BufferedGraphics,這是?個?Bitmap更好?的東西,不會造成撕裂.

封裝?下:

using;

using;

using;

using;

namespace

{

publicstaticclassFuncDraw

{

///

///根據數字坐標獲取像素位置

///

///x坐標

///y坐標

///原點位置

///原點位置

///縮放

///像素位置

publicstaticPointGetPointFromCoords(doublexCoord,doubleyCoord,intxOfft,intyOfft,doublescale)

{

returnnewPoint((int)(xCoord*scale+xOfft),(int)(-yCoord*scale+yOfft));

}

///

///

///

///數字坐標

///原點位置

///縮放

///像素位置

publicstaticPointGetPointFromCoords(PointFcoords,Pointofft,doublescale)

{

returnnewPoint((int)(coords.X*scale+offt.X),(int)(-coords.Y*scale+offt.Y));

}

///

///根據像素位置獲取數字坐標

///

///?平位置

///豎直位置

///原點位置

///原點位置

///縮放

///輸出:數字X坐標

///輸出:數字Y坐標

publicstaticvoidGetCoordsFromPoint(intx,inty,intxOfft,intyOfft,doublescale,outdoublexCoord,outdoubleyCoord)

{

xCoord=(x-xOfft)/scale;

yCoord=-((y-yOfft)/scale);

return;

}

///

///根據像素長度返回數字

///

///像素長度

///縮放

///數字

publicstaticdoubleGetNumberFromPixel(intlength,doublescale)

{

returnlength/scale;

}

///

///根據數字來獲取它距離原點的像素長度

///

///數字

///縮放

///像素長度

publicstaticdoubleGetPixelFromNumber(intnumber,doublescale)

{

returnnumber*scale;

}

///

///畫函數圖像

///

///要畫的函數

///X的取值

///繪圖Graphics

///畫線所?的Pen

///畫函數的區域

///原點的位置

///原點的位置

///縮放參數

publicstaticvoidDrawFunc(Funcfunc,IEnumerableinputs,Graphicsgraphics,Penpen,RectangledrawArea,intxOfft,i

ntyOfft,doublescale)

{

double[]nums=y();

Point[]coords=newPoint[];

intdrawAreaLeft=drawArea.X,

drawAreaRight=drawAreaLeft+,

drawAreaTop=drawArea.Y,

drawAreaBottom=drawAreaTop+;

doubley;

for(inti=0,len=;i

拆箱,所以這樣效率??些

{

y=(nums[i]);

coords[i]=GetPointFromCoords(nums[i],y,xOfft,yOfft,scale);

}

boolpoint1xIn1,

point1xIn2,

point1yIn1,

point1yIn2,

point2xIn1,

point2xIn2,

point2yIn1,

point2yIn2;

for(inti=1,len=;i

{

Pointpoint1=coords[i-1];

Pointpoint2=coords[i];

point1xIn1=point1.X>=drawAreaLeft;

point1xIn2=point1.X<=drawAreaRight;

point1yIn1=point1.Y>=drawAreaTop;

point1yIn2=point1.Y<=drawAreaBottom;

point2xIn1=point2.X>=drawAreaLeft;

point2xIn2=point2.X<=drawAreaRight;

point2yIn1=point2.Y>=drawAreaTop;

point2yIn2=point2.Y<=drawAreaBottom;

if((!(point1xIn1&&point2xIn1))||(!(point1xIn2&&point2xIn2))||(!(point1yIn1&&point2yIn1))||(!(point1yIn2&&point2yIn2)))

continue;

if(!point1xIn1)

point1=newPoint(drawAreaLeft,(int)(point1.Y+(point2.Y-point1.Y)*((double)drawAreaLeft-point1.X)/(point2.X-point1.X)));//這?是

有?些奇妙優化的,不要刪去.否則將導致某些函數?法繪制.

elif(!point2xIn1)

point2=newPoint(drawAreaLeft,(int)(point2.Y+(point1.Y-point2.Y)*((double)drawAreaLeft-point2.X)/(point1.X-point2.X)));

if(!point1xIn2)

point1=newPoint(drawAreaRight,(int)(point2.Y+(point1.Y-point2.Y)*((double)drawAreaRight-point2.X)/(point1.X-point2.X)));

elif(!point2xIn2)

point2=newPoint(drawAreaRight,(int)(point1.Y+(point2.Y-point1.Y)*((double)drawAreaRight-point1.X)/(point2.X-point1.X)));

if(!point1yIn1)

point1=newPoint((int)(point1.X+(point2.X-point1.X)*((double)drawAreaTop-point1.Y)/(point2.Y-point1.Y)),drawAreaTop);

elif(!point2yIn1)

point2=newPoint((int)(point2.X+(point1.X-point2.X)*((double)drawAreaTop-point2.Y)/(point1.Y-point2.Y)),drawAreaTop);

if(!point1yIn2)

point1=newPoint((int)(point2.X+(point1.X-point2.X)*((double)drawAreaBottom-point2.Y)/(point1.Y-point2.Y)),drawAreaBottom);

elif(!point2yIn2)

point2=newPoint((int)(point1.X+(point2.X-point1.X)*((double)drawAreaBottom-point1.Y)/(point2.Y-point1.Y)),drawAreaBottom);

ne(pen,point1,point2);

}

}

///

///畫?個坐標軸

///

///x軸要畫的數

///y軸要畫的數

///繪圖Graphics

///填充坐標軸三?所使?的Brush

///畫坐標軸所使?的Pen

///畫坐標數字所使?的Font

///畫坐標軸的區域

///原點的位置

///遠點的位置

///坐標軸上?豎線的長度

///縮放參數

///是否繪出數字

publicstaticvoidDrawShaft(IEnumerablexNumbers,IEnumerableyNumbers,Graphicsgraphics,Brushbrush,Penpen,Fontfont,

RectangledrawArea,intxOfft,intyOfft,intbarLength,doublescale,booltext)

{

ActiondrawText;

if(text)

drawText=(point,num)=>ring(ng("F2"),font,brush,point);//使?委托,那么接下來就不需要進?多余的對text的

判斷,?直接Invoke就?亍

el

drawText=(point,num)=>{};

Point

yTop=newPoint(xOfft,drawArea.Y),

yBottom=newPoint(xOfft,drawArea.Y+),//確認軸的位置

xLeft=newPoint(drawArea.X,yOfft),

xRight=newPoint(drawArea.X+,yOfft);

ne(pen,yTop,yBottom);//畫軸

ne(pen,xLeft,xRight);

inttriangleHeight=(int)((/3)*barLength);//坐標軸末端?三?的?度

Point[]

triangle1=newPoint[]{yTop,newPoint(yTop.X-barLength,yTop.Y+triangleHeight),newPoint(yTop.X+barLength,yTop.Y+triangleHeight)

},

triangle2=newPoint[]{xRight,newPoint(xRight.X-triangleHeight,xRight.Y+barLength),newPoint(xRight.X-triangleHeight,xRight.Y-barLe

ngth)};

lygon(brush,triangle1);//畫三?

lygon(brush,triangle2);

foreach(doublexinxNumbers)

{

PointnumBa=GetPointFromCoords(x,0,xOfft,yOfft,scale);

PointnumEnd=newPoint(numBa.X,numBa.Y-barLength);

ne(pen,numBa,numEnd);//畫x軸數

drawText(numBa,x);

drawText(numBa,x);

}

foreach(doubleyinyNumbers)

{

PointnumBa=GetPointFromCoords(0,y,xOfft,yOfft,scale);

PointnumEnd=newPoint(numBa.X+barLength,numBa.Y);

ne(pen,numBa,numEnd);//畫y軸數

drawText(numBa,y);

}

}

}

}

注意事項:

Graphics在繪制某些超級遠的東西時,例如這個坐標時(2147483647,2147483647),總之就是?常?,那可能會不能繪制,報

Overflow異常(已解決)

還有?些要?的內容:

CSDN?章:

CSDN?章:

更新記錄:

最新版本已經?持?定義函數表達式

項?:

項?倉庫: