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Here's my vertex shader:

    attribute vec3 aVertexPosition;
    attribute vec4 aVertexColor;
    attribute float type;

    uniform mat4 uMVMatrix;
    uniform mat4 uPMatrix;

    varying vec4 vColor;

    void main(void) {
      gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
      vColor = aVertexColor;
      if(type > 0.0) {

      } else {

      }
    }

What I want to do is pretty simple, just capture a float value named type and use it for logic operates.

The problem is, when I try to use it in Javascript, the error comes:

shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "type");
gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);


WebGL: INVALID_OPERATION: drawArrays: attribs not setup correctly main.js:253
WebGL: INVALID_OPERATION: drawArrays: attribs not setup correctly main.js:267
WebGL: INVALID_OPERATION: drawElements: attribs not setup correctly

The output of getAttribLocation is meaningful, all of them are equal greater than 0.

================= UPDATE ===================

Here's my whole project code:

https://gist.github.com/royguo/5873503

Explanation:

  • index.html Shaders script are here.
  • main.js Start the WebGL application and draw scene.
  • shaders.js Load shaders and bind attributes.
  • buffers.js Init vertex and color buffers.
  • utils.js Common used utils.
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1 に答える 1

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これは、属性を機能させるために更新したファイルを含む要点へのリンクです。type

検索すると、//ADDED CODE機能させるために必要なすべての変更を表示できるはずです。

を有効にするobjectTypeAttributeだけでなく、描画するオブジェクトごとに配列バッファーを作成する必要があります。

  triangleObjectTypeBuffer = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, triangleObjectTypeBuffer);
  objectTypes = [
    1.0, 1.0, 0.0
  ];
  gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(objectTypes), gl.STATIC_DRAW);
  triangleObjectTypeBuffer.itemSize = 1;
  triangleObjectTypeBuffer.numItems = 3;

オブジェクトを描画する前に、各オブジェクトの配列バッファをバインドします。

  gl.bindBuffer(gl.ARRAY_BUFFER, triangleObjectTypeBuffer);
  gl.vertexAttribPointer(shaderProgram.objectTypeAttribute, triangleObjectTypeBuffer.itemSize, gl.FLOAT, false, 0, 0);

あなたはおそらくすでにこれを試していて、途中で間違ってしまったでしょう。

于 2013-06-27T05:52:23.203 に答える