...

c3d.configureBackBuffer(stage.stageWidth, stage.stageHeight, 0, true);

var vertexShaderAssembler:AGALMiniAssembler = new AGALMiniAssembler();

  vertexShaderAssembler.assemble(Context3DProgramType.VERTEX, "m44 op, va0, vc0\n" + "mov v0 va1\n");

var fragmentShaderAssembler:AGALMiniAssembler = new AGALMiniAssembler();

  fragmentShaderAssembler.assemble(Context3DProgramType.FRAGMENT,  "tex ft0, v0, fs0 <2d,repeat,linear>\n" + "mov oc, ft0\n");

p3d = c3d.createProgram();

  p3d.upload(vertexShaderAssembler.agalcode, fragmentShaderAssembler.agalcode);

...

td_cover = c3d.createTexture(2048, 1024, Context3DTextureFormat.BGRA, false);

td_cover.uploadFromBitmapData(cover_d, 0);

...

c3d.setTextureAt(0, td_cover);

...