开源DirectDraw 2D引擎MCDX试用笔记（二）

清疚 2022-04-01 09:06 231阅读 0赞

刚吃了晚饭，看了会儿成龙的《重案组》，继续研究MCDX.  
  
今天把原来的泡泡堂人物素材用MCDX绘制看看，并仔细研究了一下CDXAnimation 类，发现运行结果并不是我想要的；首先我还是这样编写了代码：

![None.gif][]  playerTile  =  new  CDXTile(cdxControl1.Screen,  " player1.bmp " , 48 ,  57 ,  16 , MemTypes.SystemOnly);//16个图像帧  
![None.gif][] playerTile.ColorKey  =  Color.FromArgb( 255 ,  0 ,  255 ); //透明色＝紫色  
![None.gif][]  
![None.gif][] player  =  new  CDXSprite(playerTile, \- 1 );  
![None.gif][]  
![None.gif][] player.Animation  =  new  CDXAnimation();  
//增加每个方向的动画关键帧  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] int \[\] animUp  =  new  int \[ 6 \]  ![dot.gif][None.gif] \{ 8,9,10,11,10,9\} ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] int \[\] animDown  =  new  int \[ 6 \]  ![dot.gif][None.gif] \{ 0,1,2,3,2,1\} ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] int \[\] animLeft  =  new  int \[ 6 \]  ![dot.gif][None.gif] \{ 4,5,6,7,6,5\} ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] int \[\] animRight  =  new  int \[ 6 \]  ![dot.gif][None.gif] \{ 12,13,14,15,14,13\} ;  
![None.gif][]//添加到管理器  
![None.gif][] player.Animation.AddAnimation( 3 ,  0 ,  false , animUp);  
![None.gif][] player.Animation.AddAnimation( 3 ,  0 ,  false , animDown);  
![None.gif][] player.Animation.AddAnimation( 3 ,  0 ,  false , animLeft);  
![None.gif][] player.Animation.AddAnimation( 3 ,  0 ,  false , animRight);

看似一切正常；图像素材的结构为：4x4 ，分别是 下、左、上、右 ，索引为 0~15 共16帧画面；这个是原图： ![player1.png][]  
那么按键盘DOWN的时候按我的设置值应该是从 0 播放到 3 ，再从3 退回到 1 ；但是最终结果总是发现第0帧不显；检查MCDX自带的sample的素材可以看出第0帧就是空的；这个是MCDX的素材： ![Bug.png][]，看样子是刻意这样处理的，那我的元素显然不符合MCDX的标准了，但总不至于要我修改素材吧，那可是件痛苦的事情，还是修改MCDX的CDXTile类吧；  
  
虽然修改很容易，但还是先得了解它机制；先看一下它是如何切分图形元素的；

![None.gif][]  int  i, x, y;  
![None.gif][]  
![None.gif][] this .blockWidth  =  blockWidth;  
![None.gif][] this .blockHeight  =  blockHeight;  
![None.gif][] this .blockCount  =  blockCount;  
![None.gif][]  
![None.gif][] if ( this .blockCount  ==  0 )  
![None.gif][] this .blockCount  =  (Width  /  blockWidth)  \*  (Height  /  blockHeight);  
![None.gif][]  
![None.gif][] blockRects  =  new  System.Drawing.Rectangle\[ this .blockCount\];  
![None.gif][]  
![None.gif][] for (i  =  0 , x  =  0 , y  =  0 ; i  <  this .blockCount; i \++ , x  \+=  blockWidth)  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif]if(x > Width \- blockWidth)  
![ExpandedSubBlockStart.gif][None.gif]![ContractedSubBlock.gif][None.gif]![dot.gif][None.gif]\{  
![InBlock.gif][None.gif] x =0;  
![InBlock.gif][None.gif] y \+= blockHeight;  
![ExpandedSubBlockEnd.gif][None.gif] \}  
![InBlock.gif][None.gif]  
![InBlock.gif][None.gif] blockRects\[i\] =new System.Drawing.Rectangle(x, y, blockWidth, blockHeight);  
![ExpandedBlockEnd.gif][None.gif] \}

这里可以看到它按指定的数目切割，并把Rect保存到blockRects数组内；现在可以看看Draw的方法实现：

![None.gif][]  if (tile  ==  0  ||  tile  >  blockCount)  return ;  
![None.gif][]  
![None.gif][] if (tile  <  0 )  
![None.gif][] tile  =  animation.GetAnimationTile(tile);  
![None.gif][]  
![None.gif][] base .Draw(surface, x, y, blockRects\[tile\], bltType);

哦，原来在这里已经屏蔽掉0了；修改一下就行：

![None.gif][]  // if(tile == 0 || tile > blockCount) return;   
![None.gif][]  if (tile > blockCount) return ;

这里的Draw是调用的父类的方法，归根结底就是  
Surface.DrawFast(destX, destY, surface, srcRect, DrawFastFlags.Wait | DrawFastFlags.SourceColorKey);

--------------------

经过修改已经可以正确显示我的素材图像了；  
  
虽然目前已经有了‘良好’的开始，但还有几个小细节需要注意；还是回头看看先的代码：  
player = new CDXSprite(playerTile,-1);  
参数2是TileNumber，为什么是－1 ，还有TileNumber究竟有什么用，什么地方用到？  
  
刚开始我自己都摸不着头脑，看它自己带的CHM发现基本上什么都没说，只是告诉你，这个是一个名为TileNumber的int类型参数；但是它的源码倒是有稍微‘详细’点的注解（可以用VS.net自带的“生成注解WEB页”功能把这些信息提取出来），不过要彻底明白还是得看源码；  
首先还是打开CDXSprite类，看看这个tileNumber究竟传给谁；原来还是 Draw 方法用到：

![None.gif][]  int  tileNum  =  tileNumber;  
![None.gif][]  
![None.gif][] if (tileNum  ==  0  ||  tileNum  >  tile.BlockCount)  return ;  
![None.gif][]  
![None.gif][] //  Only calculate the tile animation if we are NOT using the  
![None.gif][] //  Tile's animations.   
![None.gif][]  if (tileNum  <  0  &&  ! useTileAnimation)  
![None.gif][] tileNum  =  animation.GetAnimationTile(tileNum);  
![None.gif][]  
![None.gif][] tile.Draw(x  \+  posX, y  \+  posY, surface, bltType, tileNum);

看来这段代码中还是屏蔽了0；暂且不管这点先，至少 tile支持Draw索引0了；现在不用再看tile.Draw了，因为上面已经看过也改过了；看看animation.GetAnimationTile方法；来自CDXAnimation 类，具体代码如下：

![None.gif][]  if (tile  >  0 )  return  tile;  
![None.gif][]  
![None.gif][] tile  =  ( \- tile) \- 1 ;  
![None.gif][] if (tile  >=  animationData.Count)  return  0 ;  
![None.gif][]  
![None.gif][] AnimationData animation  =  (AnimationData)animationData\[tile\];  
![None.gif][]  
![None.gif][] int  pos  =  (frameCounter  /  animation.frameRate)  %  (animation.anim.Length  \+  animation.pause);  
![None.gif][] if ( pos  >=  animation.anim.Length) pos  =  0 ;  
![None.gif][]  
![None.gif][] return  animation.anim\[pos\];

哦，原来tile被传递过来进行了翻译；就是这句：  
tile =  ( \- tile) \- 1 ;  
  
最终通过tile作为索引从名为animationData得ArrayList中取回关键帧得结构AnimationData；结构描述如下：

![None.gif][]  public  struct  AnimationData  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] ![dot.gif][None.gif] \{  
![ExpandedSubBlockStart.gif][None.gif]![ContractedSubBlock.gif][None.gif]/\*\*////<summary>The animation frame rate.</summary>  
![InBlock.gif][None.gif]publicint frameRate;  
![ExpandedSubBlockStart.gif][None.gif]![ContractedSubBlock.gif][None.gif]/\*\*////<summary>The length between frames.</summary>  
![InBlock.gif][None.gif]publicint pause;  
![ExpandedSubBlockStart.gif][None.gif]![ContractedSubBlock.gif][None.gif]/\*\*////<summary>Whether or not the animation uses a ping-pong cycle</summary>  
![InBlock.gif][None.gif]publicbool pingpong;  
![ExpandedSubBlockStart.gif][None.gif]![ContractedSubBlock.gif][None.gif]/\*\*////<summary>An array of tile indexes that comprise the animation frames.</summary>  
![InBlock.gif][None.gif]publicint\[\] anim;  
![ExpandedBlockEnd.gif][None.gif] \}

这个animationData就是由AddAnimation方法维护得

![None.gif][]  public  void  AddAnimation( int  frameRate,  int  pause,  bool  pingpong,  int \[\] anim)  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif]  
![ExpandedBlockEnd.gif][None.gif] \}

综上；现在控制播放动画没问题了；可以结合键盘控制来完成这个sprite程序了；

![None.gif][]  input.Update();  
![None.gif][] bool  canDrawNextFrame  =  true ;  
![None.gif][]  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] if (input.KeyState(MCDX.Keys.UpArrow)  ==  KeyStates.Press  ||  input.KeyState(MCDX.Keys.UpArrow)  ==  KeyStates.Repeat) ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] player.TileNumber =\-1;  
![InBlock.gif][None.gif] player.PosY \-- ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] \} else  if (input.KeyState(MCDX.Keys.DownArrow)  ==  KeyStates.Press  ||  input.KeyState(MCDX.Keys.DownArrow)  ==  KeyStates.Repeat) ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] player.TileNumber =\-2;  
![InBlock.gif][None.gif] player.PosY \++ ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] \} else  if (input.KeyState(MCDX.Keys.LeftArrow)  ==  KeyStates.Press  ||  input.KeyState(MCDX.Keys.LeftArrow)  ==  KeyStates.Repeat) ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] player.TileNumber =\-3;  
![InBlock.gif][None.gif] player.PosX \-- ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] \} else  if (input.KeyState(MCDX.Keys.RightArrow)  ==  KeyStates.Press  ||  input.KeyState(MCDX.Keys.RightArrow)  ==  KeyStates.Repeat) ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] player.TileNumber =\-4;  
![InBlock.gif][None.gif] player.PosX \++ ;  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] \} else ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] canDrawNextFrame =false;  
![ExpandedBlockEnd.gif][None.gif] \}   
![None.gif][]  
![ExpandedBlockStart.gif][None.gif]![ContractedBlock.gif][None.gif] if (canDrawNextFrame  &&  player.Animation != null ) ![dot.gif][None.gif] \{  
![InBlock.gif][None.gif] player.NextFrame();  
![InBlock.gif][None.gif] player.Animation.NextFrame();  
![ExpandedBlockEnd.gif][None.gif] \}

**canDrawNextFrame**是为了避免没有按键得情况下它还自动播放动画，不控制是不对的。  
  
虽然搞清楚了这些细节，但从使用角度来说是不是有点麻烦；何不干脆提供一个SetAnimationStartPos之类得方法直接制定播放起始关键帧呢？真还不知道里面还有多少弯弯道道等着去找……  
  
  
上回发的这个MCDX笔记，有兄弟说无法正常运行；我还是帖源码上来，不过我的MCDX做过部分修改，不保证到贵鸡里正常运行了；  
[点这里下载][Link 1]

[None.gif]: 
[player1.png]: /images/20220401/36c2c0e4376543cfb823e3d534e21417.png
[Bug.png]: /images/20220401/7b616bae82d54e968e3ed0215c023cf1.png
[Link 1]: http://files.cnblogs.com/Chinasf/Sprite.rar