尽管事实上建立
个地图引擎是件再简单不过事,但是我还是经常收到来自区别
人们各种邮件,询问我应该如何样去做,或者是我原来有关建立个地图引擎是简单不过事情想法是
吧,也可能是这些向我求问人本身很懒吧(你说呢?).
似乎大家都对这个主题比较感兴趣,这章我将详尽地讲解如何建立个高效2D地图引擎.瓷砖是游戏编程中
专用术语,用来产生2D游戏中场景,每个瓷砖都对应种区别地表结构;比如,海洋,草地,岩石,沙滩.虽然在3D游戏编程中使用了更为先进和生动场景生成技术,可是运用瓷砖还是能在2D游戏中生成个较生动和有趣场景.相比起来,2D中这种技术更为容易掌握和应用(而和3D游戏产生效果是样),并且运行得更为快捷.其实在所有
工作中,最主要考虑原因还是瓷砖大小.如果瓷砖太大,用它来表现地表可能就不细致,反的如果太小,游戏速度将因此而拖慢(同样大小地面,瓷砖小将使用过多数量瓷砖),并且考虑到降低问题本身复杂性方面,用这些瓷砖组合起来地图大小要正好是屏幕倍数.比如,X数量瓷砖总宽度刚好和y个屏幕宽度相等.下面提供了张简单对应表:屏幕大小 瓷砖设置方式 实际要绘制
总瓷砖数 备注640x480 5x5 128 tiles wide, 96 tiles high = 12,288 tiles to be drawn Red
10x10 64 tiles wide, 48 tiles high = 3062 tiles to be drawn Green
16x16 40 tiles wide, 30 tiles high = 1200 tiles to be drawn Green
32x32 20 tiles wide, 15 tiles high = 300 tiles to be drawn Yellow
800x600 5x5 160 tiles wide, 120 tiles high = 19,200 tiles to be drawn Red
10x10 80 tiles wide, 60 tiles high = 4800 tiles to be drawn Green
16x16 50 tiles wide, 37.5 tiles high = 1850 tiles to be drawn Green
32x32 25 tiles wide, 18.75 tiles high = 468 tiles to be drawn Yellow
1024x768 5x5 204.8 tiles wide, 153.6 tiles high = 31,212 tiles to be drawn Red
10x10 102.4 tiles wide, 76.8 tiles high = 7752 tiles to be drawn Red
16x16 64 tiles wide, 48 tile high = 3062 tiles to be drawn Green
32x32 32 tiles wide, 24 tiles high = 768 tiles to be drawn Yellow
注意到在某些解决思路方法中有些瓷砖
组合并不和屏幕大小真正切合;这表明你将需要些额外像素来填充这些地图(瓷砖组合)边缘空出来屏幕部分.我在上面表中已经用"Red"注明这些需要避免出现空白解决思路方法(和接下来"Green,Yellow"组成个"备注"项),用"Green"注明了那些合适解决思路方法,用"Yellow"注明了那些需要在必要时候才应该使用解决思路方法.如果你不打算用上面这些解决思路方法中
任何种或者在你使用DX窗口模式下情况下,上面这张表对你是没有意义;但是大体上这些解决思路方法和其它解决思路方法都是样(都按同个公式来计算),都遵循个通用原则:只有那些瓷砖数在1000-5000的间
解决思路方法都是可选,多于这个数目瓷砖数将会使要形成地图引擎运行速度打折扣.实际
组合瓷砖形成地图思路方法很简单;这里有介绍 2种主要用到思路方法:
运行时,组合瓷砖生成地图内容到个单独绘图页上-因此这种思路方法只涉及到个生成过程.如果采用这种思路方法,以上提供表项将完全无可用.并且,采用这种思路方法可能会对接下来Z轴转换和遮盖处理带来困难.运行时,在个循环里生成地图.这会在很大上降低帧播放速率(fps,frame per second),在快点机器上会更明显.但是在些优化工作后可以达到个合理播放速率.这种思路方法允许你轻松地生成动画,进行混合处理,透明处理.
我们在接下来
中将使用个简单循环来组合生成地图;以下实现组合生成地图过程可以说是在当前运行时完成,也可以说是在文章最后面链接那个中进行:Sub RenderMap(NumTilesX as
eger,NumTilesY as eger, TileWidth as eger,TileHeight as eger __ TileSourcesurf as DirectDrawSurface7, TileDestSurf as DirectDrawSurface7)
Dim X as
eger, Y as eger, r as RECT, retVal as longFor X = 0 to NumTilesX
For Y = 0 to NumTilesY
'Create our Rectangle.
r.Left = 'Left coordinate for Tile on source surface
r.Top = 'Top coordinate for Tile on Destination surface
r.Right = r.Left + TileWidth
r.Bottom = r.Top + TileHeight
'This is where we copy the tile from the source to the destination
retVal = TileDestSurf.BltFast(
(X * TileWidth), (Y * TileHeight), TileSourceSurf, r, DDBLTFAST_WAIT)Next Y
Next X
End Sub
以上
将完成个生成地图过程.我们可以对它作些改变以加快地图在每个循环里被生成速度.Remove the Multiplications. There are 6 d
ferent maths functions in the above code. This could possibly be cut down. Using Multiplication and/or division is quite costly on a loop basis. The easiest way that this can be done is by using a lookup table. On the first loop we calculate ALL the coordinates and store them in an 移除乘法运算(而改用加法或使用其它办法).以上
子用到了6个区别数学.实际上这可以被精简.使用乘法运算和逻辑运算将在个循环主体里花费不少系统占用.最直观和简单思路方法是使用个对照表.Only Draw
necessary. This is the simplest way of speeding things up. The Fruitworld game does this, all the tiles are represented by a number in an this 只在需要绘制
时候进行实际绘制.这是最让人信服提速思路方法了.游戏"水果世界"源代码使用了这个思路方法,所有瓷砖都对应个索引值被存放在个
里以供
,The other aspect of using tiles is actually drawing them. The most important thing is that they join together perfectly - and you cant see the joins between them, this is called a seamless pattern, and you can use Pa
Shop Pro to generate one for you. The next aspect is what they look like; although detail is important, there is a fine line. Assuming that you are drawing generic landscape (Grass, Sand, Water) - you dont want the user's eye to be focused on it; the grass, water and sand are the background, not the foreground.使用瓷砖
另外个方面是实际绘制它们.最重要事是要保证它们的间是无缝拼合,你至少不能看到明显缝隙,这就是人们常说"无缝拼接"
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