Alright, I'm following along with the 3rd collision detection series (the transformed per-pixel collision detection) I've done the other 2 properly, and they work. But, now I'm having trouble with the transformed collison detection. I've mimmicked the tutorial's code as close as I can see, but it's still not working. The sprite is rotating every frame, but it collides as if there's no rotation in the sprite.
| using System; |
| using Microsoft.Xna.Framework; |
| using Microsoft.Xna.Framework.Graphics; |
| using FarseerGames.FarseerPhysics.Dynamics; |
| using FarseerGames.FarseerPhysics.Factories; |
| using FarseerGames.FarseerPhysics.Collisions; |
| |
| namespace XNALibrary |
| { |
| public static class Collision |
| { |
| public static bool PerPixelCollision(Sprite spriteA, Sprite spriteB) |
| { |
| // Data for each pixel. |
| Color[] spriteAData = new Color[spriteA.texture.Width * spriteA.texture.Height]; |
| spriteA.texture.GetData(spriteAData); |
| |
| Color[] spriteBData = new Color[spriteB.texture.Width * spriteB.texture.Height]; |
| spriteB.texture.GetData(spriteBData); |
| |
| // Transform A. |
| Matrix spriteAMatrix = Matrix.CreateTranslation(new Vector3(-spriteA.Origin, 0.0f)) * |
| //Matrix.CreateScale(spriteA.Scale.X, spriteA.Scale.Y, 1.0f) * |
| Matrix.CreateRotationZ(spriteA.Rotation) * |
| Matrix.CreateTranslation(new Vector3(spriteA.Position, 0.0f)); |
| |
| // Transform B. |
| Matrix spriteBMatrix = Matrix.CreateTranslation(new Vector3(-spriteB.Origin, 0.0f)) * |
| //Matrix.CreateScale(spriteB.Scale.X, spriteB.Scale.Y, 1.0f) * |
| Matrix.CreateRotationZ(spriteB.Rotation) * |
| Matrix.CreateTranslation(new Vector3(spriteB.Position, 0.0f)); |
| |
| Matrix transformAtoB = spriteAMatrix * Matrix.Invert(spriteBMatrix); |
| |
| for (int yA = 0; yA < spriteA.texture.Height; yA++) |
| { |
| for (int xA = 0; xA < spriteB.texture.Width; xA++) |
| { |
| Vector2 positionInB = Vector2.Transform(new Vector2(xA, yA), transformAtoB); |
| |
| int xB = (int)Math.Round(positionInB.X); |
| int yB = (int)Math.Round(positionInB.Y); |
| |
| if (0 <= xB && xB < spriteB.texture.Width && |
| 0 <= yB && yB < spriteB.texture.Height) |
| { |
| // Get the colors of the overlapping pixels |
| Color colorA = spriteAData[xA + yA * spriteA.texture.Width]; |
| Color colorB = spriteBData[xA + yA * spriteB.texture.Width]; |
| |
| if (colorA.A > 0 && colorB.A > 0) |
| { |
| // Collision occured. |
| return true; |
| } |
| } |
| } |
| } |
| //} |
| return false; |
| } |
| } |
| } |
| |
Here's the image I'm using for rotation:
My sprite class is a tried-and-tested class, that doesn't seem to have any problems, which is why I think the problem lies here.
Can anyone help?
