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C#-Quelltext

vec2 invBilinear( in vec2 p, in vec2 a, in vec2 b, in vec2 c, in vec2 d )

C#-Quelltext

public float cross(Vec2 a, Vec2 b)
        {
            return a.x * b.y - a.y * b.x;
        }

        public Vec2 invBilinear(Vec2 p, Vec2 a, Vec2 b, Vec2 c, Vec2 d)
        {
            Vec2 e = new Vec2();
            e.x = b.x - a.x;
            e.y = b.y - a.y;

            Vec2 f = new Vec2();
            f.x = d.x - a.x;
            f.y = d.y - a.y;

            Vec2 g = new Vec2();
            g.x = a.x - b.x + c.x - d.x;
            g.y = a.y - b.y + c.y - d.y;

            Vec2 h = new Vec2();
            h.x = p.x - a.x;
            h.y = p.y - a.y;


            float k2 = cross(g, f);
            float k1 = cross(e, f) + cross(h, g);
            float k0 = cross(h, e);

            float w = k1 * k1 - 4.0f * k0 * k2;
            if (w < 0.0)
            {
                return new Vec2(-1.0f, -1.0f);
            }
            w = (float)Math.Sqrt(w);

            float v1 = (-k1 - w) / (2.0f * k2);
            float u1 = (h.x - f.x * v1) / (e.x + g.x * v1);

            float v2 = (-k1 + w) / (2.0f * k2);
            float u2 = (h.x - f.x * v2) / (e.x + g.x * v2);

            float u = u1;
            float v = v1;

            if (v < 0.0 || v > 1.0 || u < 0.0 || u > 1.0) { u = u2; v = v2; }
            if (v < 0.0 || v > 1.0 || u < 0.0 || u > 1.0) { u = -1.0f; v = -1.0f; }

            return new Vec2(u, v);
        }

public class Vec2
{
 public float x, y;

        public Vec2()
        {
        }

        public Vec2(float x, float y)
        {
            this.x = x;
            this.y = y;
        }
}

C#-Quelltext

 public unsafe int pnpoly(int nvert, float[] vertx, float[] verty, float testx, float testy)
        {
            int i, j, c = 0;
            for (i = 0, j = nvert - 1; i < nvert; j = i++)
            {
                if (((verty[i] > testy) != (verty[j] > testy)) &&
                 (testx < (vertx[j] - vertx[i]) * (testy - verty[i]) / (verty[j] - verty[i]) + vertx[i]))
                {
                    //c = !c;
                    if (c == 0)
                    {
                        c = 1;
                    }
                    else
                    {
                        c = 0;
                    }
                }
            }
            return c;
        }

C#-Quelltext

PIXEL_FORMAT = System.Drawing.Imaging.PixelFormat.Format32bppArgb;

C#-Quelltext

 ptr[(x * 3) + y * stride] =

C#-Quelltext

 ptr[(x * 4) + y * stride] =