I'm attempting to determine which sprite a mouse is over in an isometric 2D game. I think my best bet is to draw each sprite a different color into a separate renderTarget2D and turn it into a Texture2D at which point I can get the color data from the mouse point and check it against the drawn sprites.
The problem I'm having with that method though is that I can't change the color of the individual sprites to a solid color. If I change the Color in the spriteBatch.Draw call, it only tints the color of the sprite rather than drawing it at a solid color so the data I retrieve from the Texture doesn't help.
Any suggestions or help with drawing those sprites in a solid color?
Don't do it that way. Creating a new render target and copying the data into the memory even for a mere hundred sprites sixty times per sec is far beyond what current systems can handle.
Simply use the Contains method of the Rectangle structure:
var destination = new Rectangle(100, 100, 50, 50);
bool mouseOver = destination.Contains(mouseX, mouseY);
Related
I am writing an IOS app for chess programming using SpriteKit in Swift. While adding texture of a chess piece to an existing coloured SKSpriteNode, the SKView's background colour overwrites the SKSpriteNode's background colour.
Every chessboard square is an SKSpriteNode with Green or White colour. The expected behaviour is to retain the SKSpriteNode's colour(Green or White) in the chess board square even after adding a texture (chess piece) on top of the chess board square. (i.e) The texture's background colour must dynamically match the chessboard square's current colour (Green or White).
SKView's background colour is set to browncolor
backgroundColor = SKColor.brownColor()
SKSpriteNode for chessboard squares (green and white squares) created inside nested loop.
boardSquare.square = SKSpriteNode(color: currentColor, size: boardSquare.squareSize)
Code to add optional chess piece texture. getPieceTexture returns optional SKTexture? for the initial square positions.
boardSquare.square.texture = getPieceTexture(boardSquare)
I could not find a way to get past the issue I mentioned in the beginning. I have also attached a screenshot of the chess board which shows, Chessboard squares, Chess Pieces and SKView's background colour. Can somebody please help me get a solution for this issue?
Kindly excuse me if there are any errors in this post. This is my first post.
Thanks,
ArtBajji
Partial screenshot of the ChessBoard
Created a new SKSpriteNode with the piece texture and placed the new node in the same position as the Chess board square node. The background colour of the Chess board square did not change to SKView's background colour but remained same as the square's colour. Hope this helps others facing similar issues. Thanks.
So I am trying to get a very basic "flashlight"-style thing going in one of my games.
The way I was getting it to work, was having a layer on top of my game screen, and this layer would draw a black rectangle with ~ 80% opacity, creating the look of darkness on top of my game scene.
ccDrawSolidRect(ccp(0,0), ccp(480,320), ccc4f(0, 0, 0, 0.8));
What I want to do is draw this rectangle EVERYWHERE on the screen, except for around a cone of vision that will represent the "light source".
What this would create would be a dark overlay on top of everything except for the light, giving it the illusion of a torch/light/flashlight.
The only way I can foresee this happening is by using ccDrawSolidPoly(), but since the position of the light source changes, so would the vertices for the poly.
Any suggestions on how to achieve this would be great.
You can use ccDrawSolidPoly() and avoid having to manually update vertices. For this you can create a new subclass of CCNode representing your light object, and do your custom shape drawing in its -(void)draw method.
The ccDraw...() functions will draw relative to the local sprite coordinates, so you can then move and rotate your new sprite to suit your needs and cocos2d will do the vertices transformations for you.
Update: I found out that you might be better off subclassing CCDrawNode instead of CCNode, as it has some facilities for raw OpenGL drawing (OpenGL's vertexArrayBuffer and vertexBufferObject internal variables and a buffer for vertices, their colors and their texCoords). If your stuff is very simple, maybe subclassing the plain CCNode is enough.
Could a png be used instead as a mask, as the layer above
Like that binocular vision you sometimes see in cartoons?
Or a filter similar to a photoshop mask that darkens as it grows outwardly to wards the edge of the screen
Just a thought anyway...
A picture of more of what your trying to explain might be good too
Okay im working on making a tic tac toe game for one of my game development courses using XNA 4.0 I need to place sprites or some other objects so the game can check if the mouse is being clicked in the correct spots. I am going to use transparent sprites as a kind of button. How do I code them to go to these specific x,y coordinates. The game board is drawn on the background, I have all the coordinates to where to place these sprites. I am just stuck on putting the sprites in the correct positions.
SpriteBatch.Draw has a position parameter. Pass in an appropriately-valued Vector2.
Well if you check the Draw method you will find a parameter for the position.
Check this code sample
spriteBatch.Begin();
Vector2 pos = new Vector2(10, 10);
spriteBatch.Draw(SpriteTexture, pos, Color.White);
spriteBatch.End();
This is how you draw a sprite, with SpriteTexture as the image, on the position x10, y10 with the color White to modulate the texture.
You can also find more informations here.
Keep in mind that there are many overloaded methods to the Draw method. One you can even pass in rotation information and the like. So .Draw(...) has a lot of functionality you can use beyond just placing a sprite.
I'm just starting game development and I thought a game like Tank wars or Worms would be nice.
The hardest part I can think of so far is making the terrain destructible and I want to know how it's done before doing the easy parts.
I thought that explosion could have a mask texture which could be scaled for different weapons. Then using that mask I should make underlying terrain transparent (and optionally draw a dark border).
(source: mikakolari.fi)
How do I achieve that?
Do I have to change the alpha value pixel by pixel or can I use some kind of masking technique? Drawing a blue circle on top of the terrain isn't an option.
I have versions 3.1 and 4.0 of XNA.
This tutorial is what you are searching:
http://www.riemers.net/eng/Tutorials/XNA/Csharp/series2d.php
Capter 20: Adding explosion craters
In short:
You have 2 textures: 1 Color Texture (visible), 1 Collision Texture (invisible)
You substract the explosion image from your collision texture.
To get the dark border: expand the explosion texture and darken the color in this area.
Now you generate a new Color Texture (old color - collison = new color).
This is a difficult question to answer - because there are many ways you could do it. And there are pros and cons to each method. I'll just give an overview:
As an overall design, you need to keep track of: the original texture, the "darkness" applied, and the "transparency" applied. One thing I can say almost for sure is you want to "accumulate" the results of the explosions somewhere - what you don't want to be doing is maintaining a list of all explosions that have ever happened.
So you have surfaces for texture, darkness and transparency. You could probably merge darkness and transparency into a single surface with a single channel that stores "normal", "dark" (or a level of darkness) and "transparent".
Because you probably don't want the dark rings to get progressively darker where they intersect, when you apply an explosion to your darkness layer with the max function (Math.Max in C#).
To produce your final texture you could just write from the darkness/transparency texture to your original texture or a copy of it (you only need to update the area that each explosion touches).
Or you could use a pixel shader to combine them - the details of which are beyond the scope of this question. (Also a pixel shader won't work on XNA 4.0 on Windows Phone 7.)
You should Make a new Texure2D with the Color of desired pixels.Alpha = 0.
Color[] bits = new Color[Texture.Width * Texture.Height];
Texture.GetData(bits);
foreach(Vector2D pixel in overlapedArea)
{
int x = (int)(pixel.X);
int y = (int)(pixel.Y);
bits[x + y * texture.Width] = Color.FromNonPremultiplied(0,0,0,0));
}
Texture2D newTexture = new Texture2D(texture.GraphicsDevice, texture.Width, texture.Height);
newTexture.SetData(bits);
Now replace the new Texture2D with the Last Texture and you're good to go!
For more code about Collision, or changing texture pixels color go to this page for codes:
http://www.codeproject.com/Articles/328894/XNA-Sprite-Class-with-useful-methods
I have a based image and some sprites on top of the basd image movieclip... Some of the sprites can be drawn by the user using graphics api in actionscript 3. I can draw things on the sprites but I can't create an eraser like brush that can remove part of the unwanted drawings. I try using Alpha but no it doesn't work
I have googled about it and come up with the solution:
1) Linebitmapstyle... This solution is not the best one coz I my sprites can be moved so if I use linebitmapstyle, it does draw the pixel from the image to the sprite but if the sprite moved the drawn pixel won't change.
2) Masking may not work for me either....
What is the best way of creating the eraser
You may rather want to use a Bitmap to make such things easier to manipulate (unless you need to do scalable vector graphics of course!). To draw shapes you can still use the graphics API to create the shapes.
To do so, instantiate a "dummy" sprite (or another IBitmapDrawable implementation) to create the graphics and then "copy" them to the BitmapData the bitmapData.draw() function. This way you can for instance draw with the option BlendMode.ERASE in order remove the pixels of the shape.
Example (from the top of my mind) :
// creates a bitmap data canvas
var bitmapData:BitmapData = new BitmapData(500, 500);
// creates a bitmap display object to contain the BitmapData
addChild(new Bitmap(bitmapData));
// creates a dummy object to draw and draws a 10px circle
var brush:Sprite = new Sprite(); // note this is not even added to the stage
brush.graphics.beginFill(0xff0000);
brush.graphics.drawCircle(10, 10, 10);
// the matrix will be used to position the "brush strokes" on the canvas
var matrix:Matrix = new Matrix();
// draws a circle in the middle of the canvas
matrix.translate(250, 250);
bitmapData.draw(brush, matrix
// translates the position 5 pixels to the right to slightly erase the previously
// drawn circle creating a half moon
matrix.translate(5, 0);
bitmapData.draw(brush, matrix,null,BlendMode.ERASE);