我正在绘制一个使用AndAR在屏幕上显示的简单三角形。现在我想做一个简单的互动。我的意思是我想在点击绘制的对象时显示Toast
。我已经实现了onTouchEvent
,因此我可以获得点击屏幕的地方的XY坐标。现在我需要检查这个点是否在我的2D三角形区域。如何获得三角形点的坐标?三角是#34;坚持"到标记时,在识别标记时绘制标记,因此基于视角实时更改坐标。这是最大的问题。有什么想法吗?
public class Triangle extends ARObject implements BasicShape {
private final FloatBuffer vertexBuffer;
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 3;
static float triangleCoords[] = {
// in counterclockwise order:
25.0f, 25.622008459f, 25.0f,// top
-25.5f, -25.311004243f, 25.0f,// bottom left
25.5f, -25.311004243f, 25.0f // bottom right
};
float color[] = { 1f, 0f, 0f, 0.0f };
/**
* Sets up the drawing object data for use in an OpenGL ES context.
*/
public Triangle(String name, String patternName, double markerWidth, double[] markerCenter) {
super(name, patternName, markerWidth, markerCenter);
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (number of coordinate values * 4 bytes per float)
triangleCoords.length * 4);
// use the device hardware's native byte order
bb.order(ByteOrder.nativeOrder());
// create a floating point buffer from the ByteBuffer
vertexBuffer = bb.asFloatBuffer();
// add the coordinates to the FloatBuffer
vertexBuffer.put(triangleCoords);
// set the buffer to read the first coordinate
vertexBuffer.position(0);
}
/**
* Encapsulates the OpenGL ES instructions for drawing this shape.
*
* @param gl - The OpenGL ES context in which to draw this shape.
*/
@Override
public void draw(GL10 gl) {
super.draw(gl);
// Since this shape uses vertex arrays, enable them
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
// draw the shape
gl.glColor4f( // set color:
color[0], color[1],
color[2], color[3]);
gl.glVertexPointer( // point to vertex data:
COORDS_PER_VERTEX,
GL10.GL_FLOAT, 0, vertexBuffer);
gl.glDrawArrays( // draw shape:
GL10.GL_TRIANGLES, 0,
triangleCoords.length / COORDS_PER_VERTEX);
gl.glTranslatef(0.0f, 0.0f, 12.5f);
// Disable vertex array drawing to avoid
// conflicts with shapes that don't use it
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
}
@Override
public void init(GL10 gl10) {
}
}