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我想在android中绘制椭圆/圆,但是我很难让它显示出来。我可以在OpenGL中使用无效循环和glVertex在C中完成(不是在Android中),但是OpenGL ES看起来不同,我有些迷失方向。我的椭圆类在下面。我希望能够在构造函数中定义所有顶点,并使用draw()方法绘制它们。Android中的OpenglES椭圆
public class Ellipse {
private float _vertices[];
private FloatBuffer _vertex_buffer;
private int _segments;
public Ellipse(int segments, float width, float height) {
_vertices = new float[segments*2];
_segments = segments;
int count = 0;
for (float i = 0; i < 360.0f; i += (360.0f/_segments)) {
_vertices[count++] = (float)Math.cos(Math.PI/180.0f)*width;
_vertices[count++] = (float)Math.sin(Math.PI/180.0f)*height;
}
ByteBuffer vbb = ByteBuffer.allocateDirect(_vertices.length * 4);
vbb.order(ByteOrder.nativeOrder());
_vertex_buffer = vbb.asFloatBuffer();
_vertex_buffer.put(_vertices);
_vertex_buffer.position(0);
}
public void draw(GL10 gl) {
gl.glFrontFace(GL10.GL_CW);
gl.glVertexPointer(2, gl.GL_FLOAT, 0, _vertex_buffer);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDrawArrays(gl.GL_LINE_LOOP, 0, _segments);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
}
}