U3D Scripting API GL

- 日理万妓 2022-07-17 03:57 185阅读 0赞

http://docs.unity3d.com/ScriptReference/GL.html

# GL #

class in UnityEngine

## Description ##

Low-level graphics library.

Use this class to manipulate active transformation matrices, issue rendering commands similar to OpenGL's immediate mode and do other low-level graphics tasks. Note that in almost all cases using [Graphics.DrawMesh][] or [CommandBuffer][] is more efficient than using immediate mode drawing.  
  
GL immediate drawing functions use whatever is the "current material" set up right now (see [Material.SetPass][]). The material controls how the rendering is done (blending, textures, etc.), so unless you explicitly set it to something before using GL draw functions, the material can happen to be anything. Also, if you call any other drawing commands from inside GL drawing code, they can set material to something else, so make sure it's under control as well.  
  
GL drawing commands execute immediately. That means if you call them in Update(), they will be executed before the camera is rendered (and the camera will most likely clear the screen, making the GL drawing not visible).  
  
The usual place to call GL drawing is most often in [OnPostRender][]() from a script attached to a camera, or inside an image effect function ([OnRenderImage][]).

using UnityEngine;
    
    public class ExampleClass : MonoBehaviour
    {
    	// When added to an object, draws colored rays from the
    	// transform position.
    	public int lineCount = 100;
    	public float radius = 3.0f;
    
    	static Material lineMaterial;
    	static void CreateLineMaterial ()
    	{
    		if (!lineMaterial)
    		{
    			// Unity has a built-in shader that is useful for drawing
    			// simple colored things.
    			Shader shader = Shader.Find ("Hidden/Internal-Colored");
    			lineMaterial = new Material (shader);
    			lineMaterial.hideFlags = HideFlags.HideAndDontSave;
    			// Turn on alpha blending
    			lineMaterial.SetInt ("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.SrcAlpha);
    			lineMaterial.SetInt ("_DstBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha);
    			// Turn backface culling off
    			lineMaterial.SetInt ("_Cull", (int)UnityEngine.Rendering.CullMode.Off);
    			// Turn off depth writes
    			lineMaterial.SetInt ("_ZWrite", 0);
    		}
    	}
    
    	// Will be called after all regular rendering is done
    	public void OnRenderObject ()
    	{
    		CreateLineMaterial ();
    		// Apply the line material
    		lineMaterial.SetPass (0);
    
    		GL.PushMatrix ();
    		// Set transformation matrix for drawing to
    		// match our transform
    		GL.MultMatrix (transform.localToWorldMatrix);
    
    		// Draw lines
    		GL.Begin (GL.LINES);
    		for (int i = 0; i < lineCount; ++i)
    		{
    			float a = i / (float)lineCount;
    			float angle = a * Mathf.PI * 2;
    			// Vertex colors change from red to green
    			GL.Color (new Color (a, 1-a, 0, 0.8F));
    			// One vertex at transform position
    			GL.Vertex3 (0, 0, 0);
    			// Another vertex at edge of circle
    			GL.Vertex3 (Mathf.Cos (angle) * radius, Mathf.Sin (angle) * radius, 0);
    		}
    		GL.End ();
    		GL.PopMatrix ();
    	}
    }

Note: This class is almost always used when you need to draw a couple of lines or triangles, and don't want to deal with meshes. If you want to avoid surprises the usage pattern is this:

using UnityEngine;
    using System.Collections;
    
    public class ExampleClass : MonoBehaviour {
        void OnPostRender() {
            // Set your materials
            GL.PushMatrix();
            // yourMaterial.SetPass( );
            // Draw your stuff
            GL.PopMatrix();
        }
    }

Where at the "// Draw your stuff" you should do SetPass() on some material previously declared, which will be used for drawing. If you dont call SetPass, then you'll get basically a random material (whatever was used before) which is not good. So do it.

## Static Variables ##

## Static Functions ##

<table style="border-collapse:collapse; border-spacing:0px; width:1459px; margin:0px 0px 30px; font-size:0.875em"> 
 <tbody style="border-top:0px solid rgb(230,230,230)"> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Begin.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Begin</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Begin drawing 3D primitives.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Clear.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Clear</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Clear the current render buffer.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.ClearWithSkybox.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">ClearWithSkybox</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Clear the current render buffer with camera's skybox.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Color.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Color</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current vertex color.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.End.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">End</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">End drawing 3D primitives.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Flush.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Flush</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sends queued-up commands in the driver's command buffer to the GPU.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.GetGPUProjectionMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">GetGPUProjectionMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Compute GPU projection matrix from camera's projection matrix.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.InvalidateState.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">InvalidateState</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Invalidate the internally cached render state.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.LoadIdentity.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">LoadIdentity</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Load the identity matrix to the current modelview matrix.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.LoadOrtho.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">LoadOrtho</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Helper function to set up an ortho perspective transform.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.LoadPixelMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">LoadPixelMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Setup a matrix for pixel-correct rendering.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.LoadProjectionMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">LoadProjectionMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Load an arbitrary matrix to the current projection matrix.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.MultiTexCoord.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">MultiTexCoord</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (v.x,v.y,v.z) to the actual texture unit.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.MultiTexCoord2.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">MultiTexCoord2</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (x,y) for the actual texture unit.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.MultiTexCoord3.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">MultiTexCoord3</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (x,y,z) to the actual texture unit.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.MultMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">MultMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Multiplies the current modelview matrix with the one specified.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.PopMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">PopMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Restores both projection and modelview matrices off the top of the matrix stack.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.PushMatrix.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">PushMatrix</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Saves both projection and modelview matrices to the matrix stack.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.RenderTargetBarrier.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">RenderTargetBarrier</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Resolves the render target for subsequent operations sampling from it.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.TexCoord.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">TexCoord</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (v.x,v.y,v.z) for all texture units.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.TexCoord2.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">TexCoord2</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (x,y) for all texture units.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.TexCoord3.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">TexCoord3</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Sets current texture coordinate (x,y,z) for all texture units.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Vertex.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Vertex</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Submit a vertex.</td> 
  </tr> 
  <tr style=""> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Vertex3.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Vertex3</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Submit a vertex.</td> 
  </tr> 
  <tr style="background:rgb(248,248,248)"> 
   <td style="vertical-align:top; padding:7px 10px; width:243px"><a href="http://docs.unity3d.com/ScriptReference/GL.Viewport.html" style="color:rgb(184,60,130); outline:none" rel="nofollow">Viewport</a></td> 
   <td style="vertical-align:top; padding:7px 10px; width:1176px">Set the rendering viewport.</td> 
  </tr> 
 </tbody> 
</table>

[Graphics.DrawMesh]: http://docs.unity3d.com/ScriptReference/Graphics.DrawMesh.html
[CommandBuffer]: http://docs.unity3d.com/ScriptReference/Rendering.CommandBuffer.html
[Material.SetPass]: http://docs.unity3d.com/ScriptReference/Material.SetPass.html
[OnPostRender]: http://docs.unity3d.com/ScriptReference/Camera.OnPostRender.html
[OnRenderImage]: http://docs.unity3d.com/ScriptReference/Camera.OnRenderImage.html