libgdx 贴花未绘制到模板缓冲区中

Posted 2023-02-22

【中文标题】libgdx 贴花未绘制到模板缓冲区中

【英文标题】：libgdx decal not drawing into stencil buffer

【发布时间】：2014-07-16 13:53:29

【问题描述】：

我正在使用 libgdx 引擎开发 3d 应用程序。

我刚刚发现 decalBatch 没有绘制到模板缓冲区中。 我想为 3d 世界制作模板面具，但它根本不起作用。

这是适用于精灵批处理的代码，但不适用于贴花批处理。 请帮忙！

    Gdx.gl.glClearColor(1, 1, 1, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_STENCIL_BUFFER_BIT);
    // batch.setProjectionMatrix(camera.combined);

    // setup drawing to stencil buffer
    Gdx.gl20.glEnable(GL20.GL_STENCIL_TEST);
    Gdx.gl20.glStencilFunc(GL20.GL_ALWAYS, 0x1, 0xffffffff);
    Gdx.gl20.glStencilOp(GL20.GL_REPLACE, GL20.GL_REPLACE, GL20.GL_REPLACE);
    Gdx.gl20.glColorMask(false, false, false, false);

    // draw base pattern
    shapeRenderer.begin(ShapeType.Filled);
    shapeRenderer.identity();
    shapeRenderer.setColor(1f, 0f, 0f, 0.5f);

    shapeRenderer.rect(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(), 100, 100);

    shapeRenderer.end();

    spriteBatch.begin();
    // fix stencil buffer, enable color buffer
    Gdx.gl20.glColorMask(true, true, true, true);
    Gdx.gl20.glStencilOp(GL20.GL_KEEP, GL20.GL_KEEP, GL20.GL_KEEP);

    // draw where pattern has NOT been drawn
    Gdx.gl20.glStencilFunc(GL20.GL_NOTEQUAL, 0x1, 0xff);

    // decalBatch.add(decal);
    // decalBatch.flush();

    spriteBatch.draw(Assets.instance.background, 0, 0, Gdx.graphics.getWidth(),         Gdx.graphics.getHeight());

    // draw where pattern HAS been drawn.
    // Gdx.gl20.glStencilFunc(GL20.GL_EQUAL, 0x1, 0xff);

    // spriteBatch.draw(Assets.instance.actor1, -Gdx.graphics.getWidth() /
    // 2, -Gdx.graphics.getHeight() / 2, Gdx.graphics.getWidth(),
    // Gdx.graphics.getHeight());

    spriteBatch.end();

编辑：

我发现应该清除深度缓冲区，启用和禁用 DepthMask，但我无法管理它。

【参考方案1】：

哦，我刚刚想通了。 必须启用深度缓冲区，因为贴花在 3d 世界中。

如果有人感兴趣，这就是解决方案：

    Gdx.gl.glClearColor(1, 1, 1, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_STENCIL_BUFFER_BIT |     GL20.GL_DEPTH_BUFFER_BIT);

    // setup drawing to stencil buffer
    Gdx.gl20.glEnable(GL20.GL_STENCIL_TEST);
    Gdx.gl20.glStencilFunc(GL20.GL_ALWAYS, 0x1, 0xffffffff);
    Gdx.gl20.glStencilOp(GL20.GL_REPLACE, GL20.GL_REPLACE, GL20.GL_REPLACE);
    Gdx.gl20.glColorMask(false, false, false, false);
    Gdx.gl20.glDepthMask(false);

    // draw base pattern
    shapeRenderer.begin(ShapeType.Filled);
    shapeRenderer.identity();
    shapeRenderer.setColor(1f, 0f, 0f, 0.5f);

    shapeRenderer.rect(Gdx.graphics.getWidth() / 2, Gdx.graphics.getHeight() / 2, 100, 100);

    shapeRenderer.end();

    // fix stencil buffer, enable color buffer
    Gdx.gl20.glColorMask(true, true, true, true);
    Gdx.gl20.glDepthMask(true);
    Gdx.gl20.glStencilOp(GL20.GL_KEEP, GL20.GL_KEEP, GL20.GL_KEEP);

    // draw where pattern has NOT been drawn
    Gdx.gl20.glStencilFunc(GL20.GL_NOTEQUAL, 0x1, 0xff);

    decalBatch.add(decal);
    decalBatch.flush();

    Gdx.gl20.glDisable(GL20.GL_STENCIL_TEST);