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我试过了以下关于绘制形状和应用投影的教训,发现here,但投影似乎不起作用。据我知道我拷贝粘贴所有的代码片段在我的项目,这里是重要的部分代码:OpenGL-es投影似乎不起作用
在我Renderer
类:
@Override
public void onDrawFrame(GL10 unused) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
// Set the camera position (View matrix)
Matrix.setLookAtM(mVMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
// Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
// Draw shape
mTriangle.draw(mMVPMatrix);
}
@Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width/height;
Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
}
我Triangle
类的draw
方法:
public void draw(float[] mvpMatrix) {
GLES20.glUseProgram(mProgram);
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition"); // get handle to vertex shader's vPosition member
GLES20.glEnableVertexAttribArray(mPositionHandle); // Enable a handle to the triangle vertices
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer); // Prepare the triangle coordinate data
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor"); // get handle to fragment shader's vColor member
GLES20.glUniform4fv(mColorHandle, 1, color, 0); // Set color for drawing the triangle
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix"); // get handle to shape's transformation matrix
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0); // Apply the projection and view transformation
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertexCount); // Draw the triangle
GLES20.glDisableVertexAttribArray(mPositionHandle); // Disable vertex array
}
这个三角形还在被拉伸。我究竟做错了什么?