I am trying to figure out a way to cut out a certain region of a background texture such that a certain custom pattern is not rendered on the screen for that background. For example:
这个正方形可以是任何图案。
我使用帧缓冲区对象和模板缓冲区来实现这种效果。这是代码:
fbo.begin();
//Disables ColorMask and DepthMask so that all the rendering is done on the Stencil Buffer
Gdx.gl20.glColorMask(false, false, false, false);
Gdx.gl20.glDepthMask(false);
Gdx.gl20.glEnable(GL20.GL_STENCIL_TEST);
Gdx.gl20.glStencilFunc(GL20.GL_ALWAYS, 1, 0xFFFFFFFF);
Gdx.gl20.glStencilOp(GL20.GL_REPLACE, GL20.GL_REPLACE, GL20.GL_REPLACE);
stage.getSpriteBatch().begin();
rHeart.draw(stage.getSpriteBatch(), 1); //Draws the required pattern on the stencil buffer
//Enables the ColorMask and DepthMask to resume normal rendering
Gdx.gl20.glColorMask(true, true, true, true);
Gdx.gl20.glDepthMask(true);
Gdx.gl20.glStencilFunc(GL20.GL_EQUAL, 1, 0xFFFFFFFF);
Gdx.gl20.glStencilOp(GL20.GL_KEEP, GL20.GL_KEEP, GL20.GL_KEEP);
background.draw(stage.getSpriteBatch(), 1); //Draws the background such that the background is not rendered on the required pattern, leaving that area black.
stage.getSpriteBatch().end();
Gdx.gl20.glDisable(GL20.GL_STENCIL_TEST);
fbo.end();
然而这根本不起作用。我该如何使用模板缓冲区来做到这一点?我在理解 glStencilFunc 和 glStencilOp 方面也遇到了一些困难。如果有人能对这两件事有所了解,那将非常有帮助。
UPDATE:我也尝试过使用 glColorMask 生成类似的东西。这是代码:
Gdx.gl20.glClearColor(0, 0, 0, 0);
stage.draw();
FrameBuffer.clearAllFrameBuffers(Gdx.app);
fbo1.begin();
Gdx.gl20.glClearColor(0, 0, 0, 0);
batch.begin();
rubber.draw(batch, 1);
Gdx.gl20.glColorMask(false, false, false, true);
coverHeart.draw(batch, 1);
Gdx.gl20.glColorMask(true, true, true, false);
batch.end();
fbo1.end();
toDrawHeart = new Image(new TextureRegion(fbo1.getColorBufferTexture()));
batch.begin();
toDrawHeart.draw(batch, 1);
batch.end();
This code is producing this:
Instead of something like this: (Ignore the windows sizes and colour tones)
注意:我正在使用 libgdx 库。