Tileset发电机

Question

我一直在尝试创建一个tileset生成器（将两个图像混合在一起）但我仍然坚持使用哪种方法可以使一个纹理/图像重叠到主要图像上，或者以某种方式淡出在特定点 - 或者这是否是自动完成（或不应该完成）的事情？

绿色图像淡出时，蓝色图像应淡入绿色图像的顶部，以实现平滑过渡。如果我已有两张图片 - 我该怎么做？

现在，我只能删掉那个蓝色的部分。因此，剩下的唯一部分是绿色，当我尝试添加叠加时，它只是简单的丑陋而且我认为alpha级别应该增加（蓝色应该越靠近右下角越蓝）。

我应该关注什么想法？

我当前的方法：但是目前，这仅适用于一个角落，但应该与“所有”角落一起使用;无法弄清楚造成它的原因。

Point in polygon method

public static Bitmap GenerateTile(Bitmap bitmap, Bitmap copyFrom, int x, int y, int width, int height, Point[] cutoff)
{
        if (bitmap.Size != copyFrom.Size)
            throw new Exception("Invalid image size. Image sizes must match");

        Bitmap bmap = new Bitmap(width, height);
        Bitmap overlay = new Bitmap(width, height);

        Point min, max;
        float alpha;

        // returns minimum x, y and maximum x, y
        GetCorners(cutoff, out min, out max);

        for (int bx = x; bx < (x + width); bx++)
        {
            for (int by = y; by < (y + height); by++)
            {
                if (!IsInPolygon2(cutoff, new Point(bx, by)))
                {
                    bmap.SetPixel(bx, by, bitmap.GetPixel(bx, by));
                }
                else
                {

                    alpha = ((float)((max.X - bx) + (max.Y - by)) / (float)((max.X - min.X) + (max.Y - min.Y)));

                    if (alpha >= 0 && alpha <= 0.5f)
                    {
                        bmap.SetPixel(bx, by, Color.FromArgb((int)((alpha / 0.5f) * 255f), bitmap.GetPixel(bx, by)));
                        overlay.SetPixel(bx, by, Color.FromArgb((int)(255f - ((alpha / 0.5f) * 255f)), copyFrom.GetPixel(bx, by)));
                    }
                }
            }
        }

        using (Graphics g = Graphics.FromImage(bmap))
        {
            g.DrawImageUnscaled(overlay, 0, 0);
        }

        return bmap;
}

我的方法返回以下结果（还不好）：

// bottom right corner
points.Add(new Point(image.Width / 2, image.Height));
points.Add(new Point(image.Width, image.Height / 2));
points.Add(new Point(image.Width, image.Height));
points.Add(new Point(image.Width / 2, image.Height));

// rightside
points.Add(new Point(image.Width / 2, image.Height));
points.Add(new Point(image.Width, image.Height));
points.Add(new Point(image.Width, 0));
points.Add(new Point(image.Width / 2, 0));
points.Add(new Point(image.Width / 2, image.Height));

Answer 1

我会尝试将草和雪纹理混合在一起作为3D基元。这样，您就不需要为纹理和渐变方向的每个组合生成单独的位图。为了演示，这里是一段代码片段，您可以将其粘贴到Visual Studio中默认XNA项目的Draw方法中：

GraphicsDevice.Clear(Color.CornflowerBlue);
GraphicsDevice.BlendState = BlendState.NonPremultiplied;
effect.TextureEnabled = true;
effect.VertexColorEnabled = true;
effect.World = Matrix.CreateTranslation(new Vector3(-0.5f, -0.5f, 0))
    * Matrix.CreateScale(300)
    * Matrix.CreateTranslation(-Vector3.UnitZ);
effect.Projection = Matrix.CreateOrthographic(GraphicsDevice.Viewport.Width, GraphicsDevice.Viewport.Height, 1, 10000);
effect.View = Matrix.CreateLookAt(Vector3.UnitZ, Vector3.Zero, Vector3.UnitY);

var grassVertices = new[]
{
    new VertexPositionColorTexture(Vector3.Zero, new Color(1f, 1f, 1f, 1f), Vector2.Zero),
    new VertexPositionColorTexture(Vector3.UnitY, new Color(1f, 1f, 1f, 1f), Vector2.UnitY),
    new VertexPositionColorTexture(new Vector3(1, 1, 0), new Color(1f, 1f, 1f, 1f), Vector2.One),
    new VertexPositionColorTexture(Vector3.Zero, new Color(1f, 1f, 1f, 1f), Vector2.Zero),
    new VertexPositionColorTexture(new Vector3(1, 1, 0), new Color(1f, 1f, 1f, 1f), Vector2.One),
    new VertexPositionColorTexture(Vector3.UnitX, new Color(1f, 1f, 1f, 0f), Vector2.UnitX),
};
effect.Texture = grassTexture;
effect.Techniques[0].Passes[0].Apply();
GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, grassVertices, 0, 2);

var snowVertices = new[]
{
    new VertexPositionColorTexture(Vector3.Zero, new Color(1f, 1f, 1f, 0f), Vector2.Zero),
    new VertexPositionColorTexture(Vector3.UnitY, new Color(1f, 1f, 1f, 0f), Vector2.UnitY),
    new VertexPositionColorTexture(new Vector3(1, 1, 0), new Color(1f, 1f, 1f, 0f), Vector2.One),
    new VertexPositionColorTexture(Vector3.Zero, new Color(1f, 1f, 1f, 0f), Vector2.Zero),
    new VertexPositionColorTexture(new Vector3(1, 1, 0), new Color(1f, 1f, 1f, 0f), Vector2.One),
    new VertexPositionColorTexture(Vector3.UnitX, new Color(1f, 1f, 1f, 1f), Vector2.UnitX),
};
effect.Texture = snowTexture;
effect.Techniques[0].Passes[0].Apply();
GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, snowVertices, 0, 2);

以下是LoadContent方法初始化资源所需的内容：

grassTexture = Content.Load<Texture2D>("grass");
snowTexture = Content.Load<Texture2D>("snow");
effect = new BasicEffect(GraphicsDevice);

要在其他方向创建平铺渐变，您只需编辑grassVertices和snowVertices。对于直接向右，向左，向上或向下的淡入淡出，您需要使用四个三角形而不是两个。