OpenGLES-如何绘制填充的多边形？-OpenGLES-HowtoDrawafilledPolygon?

3  

Cocos2D is cool library wrapping OpenGL and has many useful features ( mainly for games but not limited to ).

Cocos2D是包装OpenGL的酷库,具有许多有用的功能(主要用于游戏但不限于此)。

For polygon tessellation use : http://flipcode.net/archives/Efficient_Polygon_Triangulation.shtml I've used it before and it worked well.

对于多边形镶嵌使用:http://flipcode.net/archives/Efficient_Polygon_Triangulation.shtml我以前使用它并且它运行良好。

6  

I haven't tried using OpenGL ES, but judging from a quick look in the documentation you should be able to draw a convex polygon using e.g. a "triangle fan":

我没有尝试过使用OpenGL ES,但从文档中快速浏览一下,您应该能够使用例如,绘制凸多边形。一个“三角扇”:

glVertexPointer(2, ..., arrayOfCoordinates)
...
glDrawElements(GL_TRIANGLE_FAN, ... , arrayOfIndices);

You can think of a "triangle fan" as the spokes of a bicycle-wheel dividing the area of the wheel into "triangles" (the outer edge of a bicycle wheel is of course round, but I hope you get the idea).

您可以将“三角扇”视为自行车车轮的轮辐,将车轮区域划分为“三角形”(自行车车轮的外缘当然是圆形的,但我希望您能得到这个想法)。

UPDATE: I found a small diagram on the web:

更新:我在网上找到了一个小图:

2  

On the Wikipedia Polygon Triangulation Talk page I argue that more triangles will in fact be faster.

在Wikipedia Polygon Triangulation Talk页面上,我认为更多的三角形实际上会更快。

I have written a triangulation engine that supports holes and runs in O(n log (n)) time. I tested it under Gdk and then made an Android app from it.

我编写了一个支持孔的三角测量引擎,并在O(n log(n))时间内运行。我在Gdk下测试了它,然后用它制作了一个Android应用程序。

2  

What is your final choice? I recently tested 5 of the libs listed in below link: http://vterrain.org/Implementation/Libs/triangulate.html

你最后的选择是什么?我最近测试了以下链接中列出的5个库:http://vterrain.org/Implementation/Libs/triangulate.html

But NONE of them is satisfying...

但他们中的任何一个都令人满意......

1. iphone-glu: (http://code.google.com/p/iphone-glu/)

   • Bugs in the algorithm? there are tiny holes not filled, or sometimes draw outside of the polygon

   算法中的错误?有没有填充的小孔,或者有时会在多边形外部绘制

iphone-glu:(http://code.google.com/p/iphone-glu/)算法中的错误?有没有填充的小孔,或者有时会在多边形外部绘制

2. Triangulte: (http://www.flipcode.com/archives/Efficient_Polygon_Triangulation.shtml)

   • doesn't support holes…

   不支持洞...

Triangulte:(http://www.flipcode.com/archives/Efficient_Polygon_Triangulation.shtml)不支持漏洞......

3. Triangulation: (http://www.cs.unc.edu/~dm/CODE/GEM/chapter.html)

   • Buggy, sometimes runs out of bounds, or negative index etc...

   越野车,有时跑出界限,或负面指数等...

三角测量:(http://www.cs.unc.edu/~dm/CODE/GEM/chapter.html)越野车,有时跑出界限,或负面指数等...

4. poly2tri: (http://code.google.com/p/poly2tri/)

   • Buggy, crash in certain cases

   越野车,在某些情况下崩溃

poly2tri:(http://code.google.com/p/poly2tri/)Buggy,在某些情况下崩溃

5. openglespolygon: (https://github.com/nroets/OpenGlEsPolygon)

   • imperfect algorithm? there are tiny holes (not filled) along the edges of the polygon

   不完美的算法?沿着多边形的边缘有小孔(未填充)

openglespolygon:(https://github.com/nroets/OpenGlEsPolygon)不完美的算法?沿着多边形的边缘有小孔(未填充)

0  

In non-ES OpenGL one would tend to use the tessellator from the GL Utility (glu) library. I found this project which aims to make glu available for the iPhone and it claims to support polygon tessellation - if it works, then it would be a good option.

在非ES OpenGL中,人们倾向于使用GL Utility(glu)库中的曲面细分器。我发现这个项目的目的是让iPhone可用于iPhone,它声称支持多边形镶嵌 - 如果它有效,那么它将是一个不错的选择。

0  

When you need do triangulation of polygons with holes, you can try use GPC. There is function for tringulation called gpc_polygon_to_tristrip.

当您需要对带孔的多边形进行三角测量时,您可以尝试使用GPC。有一个叫做gpc_polygon_to_tristrip的tringulation功能。

For render use GL_TRIANGLE_STRIP.

对于渲染使用GL_TRIANGLE_STRIP。

But read gpc license first!

但首先阅读gpc许可证!