我正在寻找一种无需 awt Robot
即可以编程方式截取我的 GLCanvas
的方法。
这是我当前的设置:
构造函数:
glcaps = new GLCapabilities(GLProfile.get(GLProfile.GL2));
glcaps.setDoubleBuffered(true);
glcaps.setHardwareAccelerated(true);
glcanvas = new GLCanvas(glcaps);
glcanvas.setSize(720, 720);
glcanvas.addGLEventListener(this);
glcanvas
声明为实例变量:GLCanvas glcanvas
OpenGL 初始化:
@Override
public void init(GLAutoDrawable glad) {
GL2 gl = glad.getGL().getGL2();
glu = new GLU();
gl.glEnable(GL2.GL_DEPTH_TEST);
gl.glDepthFunc(GL2.GL_LEQUAL);
gl.glShadeModel(GL2.GL_SMOOTH);
gl.glHint(GL2.GL_PERSPECTIVE_CORRECTION_HINT, GL2.GL_NICEST);
gl.glClearColor(0f, 0f, 0f, 1f);
// Some camera related code not shown
}
OpenGL 显示:
public void display(GLAutoDrawable glad) {
GL2 gl = glad.getGL().getGL2();
gl.glClear(GL2.GL_COLOR_BUFFER_BIT | GL2.GL_DEPTH_BUFFER_BIT);
...
// Orient camera and draw a simple cube
...
gl.glFlush();
}
截图方法:
BufferedImage b = new BufferedImage(glcanvas.getWidth(), glcanvas.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics g = b.createGraphics();
glcanvas.setupPrint(glcanvas.getWidth(), glcanvas.getWidth(), 50, 50, 50);
glcanvas.print(g);
try {
ImageIO.write(b, "png", new File("test.png"));
} catch (IOException ex) {
// Error handling
}
glcanvas.releasePrint();
g.dispose();
此方法有效,因为在执行时不会崩溃,但我得到的 png 文件只是黑色,没有立方体。我也尝试过使用 glReadPixels,但这也不起作用,因为它只给我一个充满 0(黑色)的缓冲区。
我认为问题在于我没有从绘图线程读取 glcanvas
。这是错误吗?如果是,我该如何解决?
感谢所有回答!
最佳答案
首先,您必须确保在呈现要捕获的内容后读取帧缓冲区。
其次,你可以这样做:
protected void saveImage(GL3 gl3, int width, int height) {
try {
BufferedImage screenshot = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics graphics = screenshot.getGraphics();
ByteBuffer buffer = GLBuffers.newDirectByteBuffer(width * height * 4);
// be sure you are reading from the right fbo (here is supposed to be the default one)
// bind the right buffer to read from
gl3.glReadBuffer(GL_BACK);
// if the width is not multiple of 4, set unpackPixel = 1
gl3.glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
for (int h = 0; h < height; h++) {
for (int w = 0; w < width; w++) {
// The color are the three consecutive bytes, it's like referencing
// to the next consecutive array elements, so we got red, green, blue..
// red, green, blue, and so on..+ ", "
graphics.setColor(new Color((buffer.get() & 0xff), (buffer.get() & 0xff),
(buffer.get() & 0xff)));
buffer.get(); // consume alpha
graphics.drawRect(w, height - h, 1, 1); // height - h is for flipping the image
}
}
// This is one util of mine, it make sure you clean the direct buffer
BufferUtils.destroyDirectBuffer(buffer);
File outputfile = new File("D:\\Downloads\\texture.png");
ImageIO.write(screenshot, "png", outputfile);
} catch (IOException ex) {
}
}
我在里面填了一些评论,如果还有什么不明白的,不要犹豫再问
关于java - 使用 JOGL 截图,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39713893/