java - 如何绘制像素化形状（LIBGDX 概念）

Question

我想以像素化风格绘制形状。我目前使用 shaperenderer 绘制的圆圈以真实像素呈现。

但我喜欢它更像素化。

我玩弄了相机和视口来获得效果，但没有成功。我更喜欢使用 FillViewport。

我们是否需要创建自己的 drawLine 函数并沿着一条线绘制小方块？或者这可以通过保持纵横比的视口来完成吗？

是否有任何小型示例项目显示如何创建像素化的简单形状。

我知道我可以自己编码，但我想避免在使用框架时。

在 skretch 中，您可以画一条线，只需指定像素大小，非常简单。

有什么提示吗？

public class SimpleCirleActor extends Actor {
        ShapeRenderer renderer;
        float radius;
        public SimpleCirleActor(int x , int y, float radius) {
            setBounds(0,0, Constants.pixelsPerSector(),Constants.pixelsPerSector());
            this.radius = radius;
            setX(x);setY(y);
            renderer = new ShapeRenderer();
        }

        @Override
        public void draw(Batch batch, float parentAlpha) {
            super.draw(batch, parentAlpha);
            renderer.setProjectionMatrix(getStage().getCamera().combined);
            renderer.begin(ShapeRenderer.ShapeType.Line);
            renderer.setColor(Color.CYAN);
            float x = getX();
            renderer.circle(x, getY(), radius);
            renderer.end();
        }

    @Override
    public void act(float delta) {
        super.act(delta);
    }

}

标签： javalibgdx

Answer 1

好吧，无聊了。干得好。

笔记：

绿色框只是为了显示帧缓冲区纹理被绘制到的位置，只需在 fbo.begin() 语句之后将填充颜色更改为零 alpha 以使其清晰。

BINDING_DEPTH_FRAMEBUFFER,BINDING_DEFAULT 变量来自我的代码。你可能不需要担心这些，除非你在切换纹理和使用定制着色器方面搞砸了。

绘制 fbo，batch.draw(fbo.getColorBufferTexture(), 20, 20, 200, 200, 0, 0, 1, 1); 希望这对你来说没问题。如果你想旋转 fbo，你应该能够从你的相机创建一个旋转的投影矩阵。如果您想使用定制着色器，您只需小心将 fbo 作为纹理链接到着色器。

package com.funferret.pixelshapes;

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.glutils.FrameBuffer;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.utils.ScreenUtils;

public class MyGdxGame extends ApplicationAdapter {
    ShapeRenderer shapeBatch;
    SpriteBatch batch;
    Texture img;
    FrameBuffer fbo;
    public OrthographicCamera fboCamera;

    int fboWidth=40;
    int fboHeight=40;
    int BINDING_DEPTH_FRAMEBUFFER=3;
    int BINDING_DEFAULT=0;

    void createFrameBuffer()
    {
        if (fbo!=null)
        {
            fbo.dispose();
        }
        fbo = new FrameBuffer(Pixmap.Format.RGBA8888, fboWidth, fboHeight, false);
        fbo.getColorBufferTexture().setFilter(Texture.TextureFilter.Nearest, Texture.TextureFilter.Nearest);
        fbo.getColorBufferTexture().bind(BINDING_DEPTH_FRAMEBUFFER);
        Gdx.graphics.getGL20().glActiveTexture(GL20.GL_TEXTURE0 + BINDING_DEFAULT); //make sure this is set to 0 for batch draws
        fboCamera=new OrthographicCamera();
        fboCamera.setToOrtho(false, fboWidth, fboHeight);
        fboCamera.update();
    }

    @Override
    public void create () {
        batch = new SpriteBatch();
        shapeBatch=new ShapeRenderer();
        img = new Texture("badlogic.jpg");
    }

    @Override
    public void render ()
    {
    //I had some initialisation problems with the fbo when trying to create a framebuffer. Need to be absolutely certain
        //size is correct and opengl context is set up before creating the framebuffer (as far as I remember). This if statement and the
        //createFrameBuffer function works for me and will allow you to change the size of fboWidth/fboHeight on the fly (though will cause stutters if you do)
        if ((fbo==null) || (fbo.getWidth()!=fboWidth) || (fbo.getHeight()!=fboHeight))
        {
            createFrameBuffer();
        }

        //start drawing to a small framebuffer, that we will then scale up to create a pixelated effect
        fbo.begin();
        ScreenUtils.clear(0, 1, 0, 0.5f);
        shapeBatch.begin(ShapeRenderer.ShapeType.Line);
        shapeBatch.setProjectionMatrix(fboCamera.combined);
        Gdx.gl.glDisable(GL20.GL_BLEND);
        shapeBatch.setColor(1f, 0f, 1f, 1);
        shapeBatch.circle(20,20,15,10);
        shapeBatch.end();
        fbo.end();


        ScreenUtils.clear(1, 0, 0, 1);
        batch.begin();
        batch.draw(img, 0, 0);
        batch.draw(fbo.getColorBufferTexture(), 20, 20, 200, 200, 0, 0, 1, 1);
        batch.end();
    }
    
    @Override
    public void dispose () {
        batch.dispose();
        img.dispose();
        shapeBatch.dispose();
        fbo.dispose();
    }
}