@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
// 设置视窗大小及位置
GLES20.glViewport(0, 0, width, height);
// 计算GLSurfaceView的宽高比
float ratio = (float) width / height;
// 调用此方法计算产生透视投影矩阵
MatrixState.setProjectFrustum(-ratio, ratio, -1, 1, 1, 100);
// 调用此方法产生摄像机9参数位置矩阵
MatrixState.setCamera(cx, 0, cz, 0, 0, 0, 0f, 1.0f, 0.0f);
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
// 设置屏幕背景色RGBA
GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
// 打开深度检测
GLES20.glEnable(GLES20.GL_DEPTH_TEST);
MatrixState.setInitStack();
treeTextureId = initTexture(R.drawable.tree);
desert =
new Desert(
MySurfaceView.this,
new float[] {
0, 0, 0, 6, 6, 6,
6, 6, 6, 0, 0, 0
},
30,
20);
desertId = initTexture(R.drawable.desert);
group = new TreeGroup(MySurfaceView.this, treeTextureId);
Collections.sort(mRender.group.trees);
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
x = event.getX();
y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
flag = true;
new Thread() {
@Override
public void run() {
while (flag) {
if (x > 0 && x < WIDTH / 2 && y > 0 && y < HEIGHT / 2) { // 向前
Offset = Offset - 0.5f;
} else if (x > WIDTH / 2 && x < WIDTH && y > 0 && y < HEIGHT / 2) { // 向后
Offset = Offset + 0.5f;
} else if (x > 0 && x < WIDTH / 2 && y > HEIGHT / 2 && y < HEIGHT) {
direction = direction + DEGREE_SPAN;
} else if (x > WIDTH / 2 && x < WIDTH && y > HEIGHT / 2 && y < HEIGHT) {
direction = direction - DEGREE_SPAN;
}
try {
Thread.sleep(100);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}.start();
break;
case MotionEvent.ACTION_UP:
flag = false;
break;
}
// 设置新的观察目标点XZ坐标
cx = (float) (Math.sin(direction) * Offset); // 观察目标点x坐标
cz = (float) (Math.cos(direction) * Offset); // 观察目标点z坐标
// 计算所有树的朝向
mRender.group.calculateBillboardDirection();
// 给树按照离视点的距离排序
Collections.sort(mRender.group.trees);
// 设置新的摄像机位置
MatrixState.setCamera(cx, 0, cz, 0, 0, 0, 0, 1, 0);
return true;
}
@Override
public void onDrawFrame(GL10 gl) {
// 清除深度缓冲与颜色缓冲
GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
MatrixState.pushMatrix();
MatrixState.translate(0, -2, 0);
desert.drawSelf(desertId);
MatrixState.popMatrix();
// 开启混合
GLES20.glEnable(GLES20.GL_BLEND);
// 设置混合因子
GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
MatrixState.pushMatrix();
MatrixState.translate(0, -2, 0);
group.drawSelf();
MatrixState.popMatrix();
// 关闭混合
GLES20.glDisable(GLES20.GL_BLEND);
}