Win32 API：貼圖技巧

若您覺得文章寫得不錯，請點選文章上的廣告，來支持小編，謝謝。

透空效果：

原圖

     // 背景圖

     SelectObject(mdc, bg);

     BitBlt(hdc, 0 ,0 , 600, 450, mdc, 0, 0, SRCCOPY);

     // 透空圖

     SelectObject(mdc, dra);

     BitBlt(hdc, 280, 320, 85, 99, mdc, 85, 0, SRCAND);

     BitBlt(hdc, 280, 320, 85, 99, mdc, 0, 0, SRCPAINT);

結果

半透明：

公式：半透明圖色彩 = 前景圖色彩 * 不透明度 + 背景圖色彩 * (1 -不透明度)

// 半透明處理，處理後將半透明圖存回result

HBITMAP bg, result;

     BITMAP bm1, bm2;

     unsigned char *px1, *px2;

     px1 = new unsigned char [bm1.bmHeight * bm1.bmWidthBytes];

     GetBitmapBits(bg, bm1.bmHeight * bm1.bmWidthBytes, px1);

     //處理前景圖

     result = (HBITMAP)LoadImage(NULL,"result.bmp", IMAGE_BITMAP, 298, 329, LR_LOADFROMFILE);

     GetObject(result, sizeof(BITMAP), &bm2);

     px2 = new unsigned char [bm2.bmHeight * bm2.bmWidthBytes];

     GetBitmapBits(result, bm2.bmHeight * bm2.bmWidthBytes, px2);

     int xend,yend;

     int x,y,i;                 //迴圈用變數

     int rgb_b;

     int PxBytes = bm1.bmBitsPixel / 8 ;

     xend = xstart + 298;

     yend = ystart + 329;

     //處理背景圖像素顏色

     for(y = ystart; y < yend; y++)

     {

           for(x = xstart; x < xend; x++)

           {

                rgb_b = y * bm1.bmWidthBytes + x * PxBytes ;

                px1[rgb_b] = px1[rgb_b] * 0.7;      

                px1[rgb_b+1] = px1[rgb_b+1] * 0.7;  

                px1[rgb_b+2] = px1[rgb_b+2] * 0.7;  

           }

     }

     //處理前景圖像素顏色

     for(y = 0; y < (bm2.bmHeight); y++)

     {

           for(x = 0; x < bm2.bmWidth; x++)

           {

                rgb_b = y * bm2.bmWidthBytes + x * PxBytes ;

                i = (ystart+y) * bm1.bmWidthBytes + (xstart+x) * PxBytes;

                px2[rgb_b]   = px2[rgb_b] * 0.3 + px1[i];

                px2[rgb_b+1] = px2[rgb_b+1] * 0.3 + px1[i+1];  

                px2[rgb_b+2] = px2[rgb_b+2] * 0.3 + px1[i+2];  

           }

     }

     SetBitmapBits(result, bm2.bmHeight * bm2.bmWidthBytes, px2);

     delete [] px1;

     delete [] px2;

結果

平面貼圖：用矩陣來存如下：0表示背景、1是第一種前景、2是第二種前景．．．

     int mapIndex[rows*cols] = { 2,2,2,2,0,1,0,1,

                                0,2,2,0,0,0,1,1, 

                                0,0,0,0,0,0,0,1, 

                                2,0,0,0,0,0,2,2, 

                                2,0,0,0,0,2,2,2, 

                                2,0,0,0,2,2,0,0, 

                                0,0,2,2,2,0,0,1, 

                                0,0,2,0,0,0,1,1 };

斜角地圖貼圖：一樣是用矩陣存，但貼圖的座標要更改

     int xstart,ystart;

     xstart = 32 * (rows-1);

     ystart = 0;

     //依mapIndex 陣列中的定義取出對應圖塊，進行地圖拼接

     for (i=0;i<rows*cols;i++)

     {

           SelectObject(bufdc,map[mapIndex[i]]);

           rowNum = i / cols;     //求列編號

           colNum = i % cols;     //求行編號

           x = xstart + colNum * 32 + rowNum * (-32); //求貼圖X 座標

           y = ystart + rowNum * 16 + colNum * 16;     //求貼圖Y 座標

          

           BitBlt(mdc,x,y,64,32,bufdc,64,0,SRCAND);

           BitBlt(mdc,x,y,64,32,bufdc,0,0,SRCPAINT);

     }