我试图弄清楚如何将不同的纹理放入不同的纹理单元并选择要绘制的纹理。我的onDrawFrame()方法中有以下代码
int[] texture = new int[7];
texture[0] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture1);
texture[1] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture2);
texture[2] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture3);
texture[3] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture4);
texture[4] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture5);
texture[5] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture6);
texture[6] =TextureHelper.loadTexture(mActivityContext,R.drawable.texture7);
for (int i = 0; i < 7; i ++) {
GLES20.glActiveTexture(GLES20.GL_TEXTURE0 + i);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture[i]);
GLES20.glUniform1i(mTextureUniformHandle, i);
Matrix.setIdentityM(mModelMatrix, 0);
Matrix.translateM(mModelMatrix, 0, -0.60f + 0.2f * i, 0.0f, 0.0f);
draw();
}
这应该做的是将七个不同的纹理加载到单独的纹理单元中并绘制立方体，每个立方体具有不同的纹理。然而，最终发生的是所有的立方体最终都是用第一个纹理绘制的。
如果我更改GLES20.glActiveTexture(GLES20.GL_TEXTURE0 + i)为GLES20.glActiveTexture(GLES20.GL_TEXTURE0)和GLES20.glUniform1i(mTextureUniformHandle, i)，它可以正常工作GLES20.glUniform1i(mTextureUniformHandle, 0)，但它只使用一个纹理单元并每次都替换该单元中的纹理，这不是我想要做的。
我究竟做错了什么？提前致谢。
编辑：
顶点着色器：
"uniform mat4 u_MVPMatrix;" + // A constant representing the
// combined
// model/view/projection matrix.
"uniform mat4 u_MVMatrix;" + // A constant representing the
// combined model/view matrix.
"attribute vec4 a_Position;" + // Per-vertex position
// information we will pass in.
"attribute vec4 a_Color;" + // Per-vertex color information we
// will pass in.
"attribute vec2 a_TexCoordinate;" + // Per-vertex texture
// coordinate information we
// will pass in.
"varying vec3 v_Position;" + // This will be passed into the
// fragment shader.
"varying vec4 v_Color;" + // This will be passed into the
// fragment shader.
"varying vec2 v_TexCoordinate;" + // This will be passed into
// the fragment shader.
// The entry point for our vertex shader.
"void main()" + "{" +
// Transform the vertex into eye space.
"v_Position = vec3(u_MVMatrix * a_Position);" +
// Pass through the color.
"v_Color = a_Color;" +
// Pass through the texture coordinate.
"v_TexCoordinate = a_TexCoordinate;" +
// gl_Position is a special variable used to store the final
// position.
// Multiply the vertex by the matrix to get the final point in
// normalized screen coordinates.
"gl_Position = u_MVPMatrix * a_Position;" + "} ";
片段着色器：
"precision mediump float;" + // Set the default precision to medium. We don't need as high of a
// precision in the fragment shader.
"uniform sampler2D u_Texture;" + // The input texture.
"varying vec3 v_Position;" + // Interpolated position for this fragment.
"varying vec4 v_Color;" + // This is the color from the vertex shader interpolated across the
// triangle per fragment.
"varying vec2 v_TexCoordinate;" + // Interpolated texture coordinate per fragment.
// The entry point for our fragment shader.
"void main()" +
"{" +
// Multiply the color by the diffuse illumination level and texture value to get final output color.
"gl_FragColor = (v_Color * texture2D(u_Texture, v_TexCoordinate));" +
"}";
绘制（）方法：
public void draw() {
// Pass in the position information
mCubePositions.position(0);
GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false, 0, mCubePositions);
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Pass in the color information
mCubeColors.position(0);
GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, GLES20.GL_FLOAT, false, 0, mCubeColors);
GLES20.glEnableVertexAttribArray(mColorHandle);
// Pass in the texture coordinate information
mCubeTextureCoordinates.position(0);
GLES20.glVertexAttribPointer(mTextureCoordinateHandle, mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 0, mCubeTextureCoordinates);
GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);
// This multiplies the view matrix by the model matrix, and stores the
// result in the MVP matrix
// (which currently contains model * view).
Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);
// Pass in the modelview matrix.
GLES20.glUniformMatrix4fv(mMVMatrixHandle, 1, false, mMVPMatrix, 0);
// This multiplies the modelview matrix by the projection matrix, and
// stores the result in the MVP matrix
// (which now contains model * view * projection).
Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
// Pass in the combined matrix.
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0);
// Draw the cube.
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 6);
}
分配 mTextureUniformHandle ：
mTextureUniformHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_Texture");