我在这里阅读了文档：
http://help.adobe.com/en_US/as3/dev/WS5b3ccc516d4fbf351e63e3d118a9b90204-7d5b.html
Flash Player 11.4 和 AIR 3.4 支持运行时纹理压缩，这在某些情况下很有用，例如从矢量图渲染动态纹理时。要使用运行时纹理压缩，请执行以下步骤：
通过调用 Context3D.createTexture() 方法创建纹理对象，在第三个参数中传递 flash.display3D.Context3DTextureFormat.COMPRESSED 或 flash.display3D.Context3DTextureFormat.COMPRESSED_ALPHA。使用 createTexture() 返回的 flash.display3D.textures.Texture 实例，调用 flash.display3D.textures.Texture.uploadFromBitmapData() 或 flash.display3D.textures.Texture.uploadFromByteArray()。这些方法一步上传和压缩纹理。
我尝试按照步骤操作，但出现错误：
错误：错误 #3763：采样器 0 绑定的纹理与 AGAL 中指定的读取模式不匹配。必须显式声明读取压缩或单/双通道纹理。在 flash.display3D::Context3D/drawTriangles()
我也应该在 agal 方面放一些说明吗？
这是完整的代码：
注意：在我尝试并失败后，我没有使用嵌入的 png 作为纹理，只是一个空的 bitmapdata 创建的运行时无法在我的 macos flash 播放器 11.8 上运行
从这里抓取AGALMiniAssembler.as：https://github.com/PrimaryFeather/Starling-Framework/blob/master/starling/src/com/adobe/utils/AGALMiniAssembler.as
package sandbox
{
import com.adobe.utils.AGALMiniAssembler;
import com.adobe.utils.PerspectiveMatrix3D;
import flash.display.BitmapData;
import flash.display.Sprite;
import flash.display.Stage3D;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.display3D.Context3D;
import flash.display3D.Context3DProfile;
import flash.display3D.Context3DProgramType;
import flash.display3D.Context3DRenderMode;
import flash.display3D.Context3DTextureFormat;
import flash.display3D.Context3DVertexBufferFormat;
import flash.display3D.IndexBuffer3D;
import flash.display3D.Program3D;
import flash.display3D.VertexBuffer3D;
import flash.display3D.textures.Texture;
import flash.events.Event;
import flash.geom.Matrix3D;
import core.Scene3D;
[SWF(width="600",height="800",frameRate="60")]
public class TestCompressedTexture extends Sprite
{
[Embed(source="../../assets/tex_cube.png")]
private var TexCube:Class;
private var _swfHeight:int;
private var _swfWidth:int;
public var context3D:Context3D;
public var viewMatrix:Matrix3D = new Matrix3D();
public var projectionMatrix:PerspectiveMatrix3D = new PerspectiveMatrix3D();
public var meshIndexData:Vector.<uint> = Vector.<uint>
([
0, 1, 2, 0, 2, 3,
]);
public var meshVertexData:Vector.<Number> = Vector.<Number>([
//x,y,z u,v nx,ny,nz
-1, -1, 1, 0, 0, 0, 0, 1,
1, -1, 1, 1, 0, 0, 0, 1,
1, 1, 1, 1, 1, 0, 0, 1,
-1, 1, 1, 0, 1, 0, 0, 1,
]);
private var indexBuffer:IndexBuffer3D;
private var vertexBuffer:VertexBuffer3D;
private var program:Program3D;
private var _modelViewProjection:Matrix3D = new Matrix3D();
private var modelMatrix:Matrix3D = new Matrix3D();
private var texture:Texture;
private var uvBuffer:VertexBuffer3D;
public function TestCompressedTexture()
{
_swfHeight = 600;
_swfWidth = 800;
if (stage!=null){
init();
}else{
addEventListener(Event.ADDED_TO_STAGE,init);
}
projectionMatrix.identity();
projectionMatrix.perspectiveFieldOfViewRH(45.0,_swfWidth/_swfHeight,0.001,100.0);
modelMatrix.identity();
viewMatrix.identity();
viewMatrix.prependTranslation(0,0,-5);
super();
}
private function init(e:Event=null):void{
if (hasEventListener(Event.ADDED_TO_STAGE))
removeEventListener(Event.ADDED_TO_STAGE,init);
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
stage.stage3Ds[0].addEventListener(Event.CONTEXT3D_CREATE,onContext3DCreate);
stage.stage3Ds[0].requestContext3D(Context3DRenderMode.AUTO,Context3DProfile.BASELINE_EXTENDED);
}
protected function onContext3DCreate(e:Event):void
{
removeEventListener(Event.ENTER_FRAME,enterFrame);
var t:Stage3D = e.target as Stage3D;
context3D = t.context3D;
if (context3D == null){
return;
}
context3D.enableErrorChecking = true;
context3D.configureBackBuffer(_swfWidth,_swfHeight,0,true);
dispatchEvent(new Event(Scene3D.SCENE3D_CREATED));
createProgram();
createTexture();
createBuffer();
addEventListener(Event.ENTER_FRAME,enterFrame);
}
public function createProgram():void{
var vsa:AGALMiniAssembler = new AGALMiniAssembler();
var vs:String =
"m44 op, va0, vc0\n" +
"mov v0, va1\n" //uv
;
var fs:String =
"tex ft0, v0, fs0 <2d,repeat,nomip>\n"+
"mov oc ft0 \n"
;
program = vsa.assemble2(context3D,1,vs,fs);
context3D.setProgram(program);
}
public function createBuffer():void{
indexBuffer = context3D.createIndexBuffer(meshIndexData.length);
indexBuffer.uploadFromVector(meshIndexData,0,meshIndexData.length);
vertexBuffer = context3D.createVertexBuffer(meshVertexData.length/8,8);
vertexBuffer.uploadFromVector(meshVertexData,0,meshVertexData.length /8);
}
public function createTexture():void{
// texture = context3D.createTexture(512, 512, Context3DTextureFormat.BGRA, false);
texture = context3D.createTexture(512, 512, Context3DTextureFormat.COMPRESSED, false);
// var texCube:BitmapData = new TexCube().bitmapData;
// trace(texCube.height,texCube.width);
var bmd:BitmapData = new BitmapData(512,512);
texture.uploadFromBitmapData(bmd);
}
protected function enterFrame(event:Event):void
{
context3D.clear();
_modelViewProjection.identity();
_modelViewProjection.append(modelMatrix);
_modelViewProjection.append(viewMatrix);
_modelViewProjection.append(projectionMatrix);
// pass our matrix data to the shader program
context3D.setProgramConstantsFromMatrix(
Context3DProgramType.VERTEX,
0, _modelViewProjection, true );
context3D.setVertexBufferAt(0, vertexBuffer, 0, Context3DVertexBufferFormat.FLOAT_3);
context3D.setVertexBufferAt(1, vertexBuffer, 3, Context3DVertexBufferFormat.FLOAT_2);
context3D.setTextureAt(0,texture);
context3D.drawTriangles(indexBuffer);
context3D.present();
}
}
}