[游戏模版8] Win32 透明贴图

最新推荐文章于 2023-04-15 00:32:42 发布

转载最新推荐文章于 2023-04-15 00:32:42 发布 · 131 阅读

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原文链接：https://yq.aliyun.com/articles/357264

本文介绍了一种在C++游戏中实现图片透明效果的方法。通过使用Win32 API中的BitBlt函数配合特定的图片格式，实现了dra.bmp图片在背景图片上的透明显示。这种方法涉及到图像科学知识，并详细介绍了如何准备dra.bmp文件以达到预期的视觉效果。

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>_<:The same with previous introduction. In the InitInstance fanction make a little change:

>_<:Yes just add another picture "dra.bmp" and give the handle to dra.And then call function MyPaint(...)

1 hdc=GetDC(hWnd);
2 mdc=CreateCompatibleDC(hdc);
3 
4 bg=(HBITMAP)LoadImage(NULL,"bg.bmp",IMAGE_BITMAP,600,450,LR_LOADFROMFILE);
5 dra=(HBITMAP)LoadImage(NULL,"dra.bmp",IMAGE_BITMAP,64,124,LR_LOADFROMFILE);
6 //名、类型、大小、加载方式；
7 
8 MyPaint(hdc);
9 ReleaseDC(hWnd,hdc);

>_<:As following here is the MyPaint(...) function:

>_<:In this function :

firstly, move the picture "bg.bmp" to CompatibleDC mdc by its handle bg.
Then copy mdc to hdc. Until now there is no any change.
And then move dra to mdc,latter using twice BitBlt.

Here we can see:the seventh line, only use mdc's lower part do an operation SRCAND; the eighth line,use another part of mdc do an operation SRCPAINT. (Why through the two steps can achieve transparency? It involves some knowledge of image science, here will not introduce. )

>_<!However,one thing must be reminded:the picture of dra.bmp must use following style form:

Yes,the part that you don't want to show must use the black background and this part will be done the operation late than another part.And another part includes that you want to show must be black, you don't want to show must be white!

>_<:MyPaint(...)

1 void MyPaint(HDC hdc)
2 {
3     SelectObject(mdc,bg);
4     BitBlt(hdc,0,0,1366,768,mdc,0,0,SRCCOPY);//在窗口位置、大小、原图剪切位
5 
6     SelectObject(mdc,dra);
7     BitBlt(hdc,200,320,64,62,mdc,0,62,SRCAND);
8     BitBlt(hdc,200,320,64,62,mdc,0,0,SRCPAINT);
9 }