LIBGDX:如何使用 shaperenderer 绘制填充多边形?

2022-01-12 00:00:00 java libgdx

我已经使用顶点数组定义了一个形状:

I have defined a shape using an array of vertices:

float[] points =  new float[]{50,60,50,70,60,70, 60,60,50,60};

我在这里画这个:

shapeRenderer.polygon(floatNew);

这只是给出了形状的轮廓.
如何用颜色填充它?
谢谢

This just gives an outline of the shape.
How do I fill it with colour?
Thanks

推荐答案

目前ShapeRenderer支持多边形绘制(按线)，但不支持填充.

Currently, ShapeRenderer supports polygon drawing (by line) but not filling.

这段代码在三角形上剪裁多边形，然后分别绘制每个三角形.

This code is clipping the polygon on triangles, and then drawing each triangle separately.

像这样编辑 ShapeRenderer.java:

Edit ShapeRenderer.java like this:

EarClippingTriangulator ear = new EarClippingTriangulator();

public void polygon(float[] vertices, int offset, int count)
{
    if (shapeType != ShapeType.Filled && shapeType != ShapeType.Line)
        throw new GdxRuntimeException("Must call begin(ShapeType.Filled) or begin(ShapeType.Line)");
    if (count < 6)
        throw new IllegalArgumentException("Polygons must contain at least 3 points.");
    if (count % 2 != 0)
        throw new IllegalArgumentException("Polygons must have an even number of vertices.");

    check(shapeType, null, count);

    final float firstX = vertices[0];
    final float firstY = vertices[1];
    if (shapeType == ShapeType.Line)
    {
        for (int i = offset, n = offset + count; i < n; i += 2)
        {
            final float x1 = vertices[i];
            final float y1 = vertices[i + 1];

            final float x2;
            final float y2;

            if (i + 2 >= count)
            {
                x2 = firstX;
                y2 = firstY;
            } else
            {
                x2 = vertices[i + 2];
                y2 = vertices[i + 3];
            }

            renderer.color(color);
            renderer.vertex(x1, y1, 0);
            renderer.color(color);
            renderer.vertex(x2, y2, 0);

        }
    } else
    {
        ShortArray arrRes = ear.computeTriangles(vertices);

        for (int i = 0; i < arrRes.size - 2; i = i + 3)
        {
            float x1 = vertices[arrRes.get(i) * 2];
            float y1 = vertices[(arrRes.get(i) * 2) + 1];

            float x2 = vertices[(arrRes.get(i + 1)) * 2];
            float y2 = vertices[(arrRes.get(i + 1) * 2) + 1];

            float x3 = vertices[arrRes.get(i + 2) * 2];
            float y3 = vertices[(arrRes.get(i + 2) * 2) + 1];

            this.triangle(x1, y1, x2, y2, x3, y3);
        }
    }
}

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