Trigonometry Fail! Help!

[therevillsParticipant]

I’m trying to shoot a bullet out of hard point which is an offset of the main ship, but my trig is failing

Here is some cut down runnable code, I would like the bullet to come out of the red square:

W = Move forward
S = Move Backward
A = Rotate Left
D = Rotate Right
Space = Shoot

Monkey

Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix canvas.DrawText("r = " +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = r Local ofx:Int = 100 Local ofy:Int = 50 Local gunPosX:Float = x + ofx * Cos(r) - ofy * Sin(r) Local gunPosY:Float = y + ofy * Sin(r) + ofy * Cos(r) Self.x = gunPosX Self.y = gunPosY Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(r) * speed Local dy:Float = Cos(r) * speed x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate( RotationDisplay ) canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

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Namespace myapp   #Import "<std>" #Import "<mojo>"   Using std.. Using mojo..   Const Size:=New Vec2i( 640,480 )   Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End   Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End   Method OnMeasure:Vec2i() Override Return Size End End   Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End   Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix   canvas.DrawText("r = "  +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End   x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End   Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = r Local ofx:Int = 100 Local ofy:Int = 50    Local gunPosX:Float = x + ofx * Cos(r) - ofy * Sin(r) Local gunPosY:Float = y + ofy * Sin(r) + ofy * Cos(r) Self.x = gunPosX Self.y = gunPosY Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(r) * speed Local dy:Float = Cos(r) * speed x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate( RotationDisplay ) canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End   Function Main() New AppInstance New MyWindow App.Run() End

Could someone please let me know where I am going wrong?

[AdamStrangeParticipant]

Here you go…

Monkey

[crayon-5cba159db2435965715919 inline="true" ]Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window", Size.X, Size.Y, WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local xr:float = x + (Sin(r) * 100) Local yr:float = y + (Cos(r) * 100) canvas.DrawLine( x, y, xr, yr ) canvas.Color = Color.Blue canvas.DrawRect(x-5, y-5, 10, 10) ' Local matrix:=canvas.Matrix ' canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) ' canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) ' canvas.Color = Color.Blue ' canvas.DrawRect(-5, -5, 10, 10) ' canvas.Color = Color.Red ' canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) ' canvas.Matrix=matrix canvas.DrawText("r = " +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.Up) velocity.x += (Sin(r) * factor - velocity.x) * am velocity.y += (Cos(r) * factor - velocity.y) * am Elseif Keyboard.KeyDown(Key.Down) velocity.x += (-Sin(r) * factor - velocity.x) * am velocity.y += (-Cos(r) * factor - velocity.y) * am Else velocity.x *= .99 velocity.y *= .99 End If Keyboard.KeyDown(Key.Left) r += .1 End If Keyboard.KeyDown(Key.Right) r -= .1 End x += velocity.x y += velocity.y If Keyboard.KeyDown(Key.Space)then New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = r ' Print x+" "+y+" "+r Local gunPosX:Float = x + (Sin(r) * 100) Local gunPosY:Float = y + (Cos(r) * 100) Self.x = gunPosX Self.y = gunPosY Self.timeToLive = 40 Self.sizeW = 10 Self.sizeH = 10 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(r) * speed Local dy:Float = Cos(r) * speed x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour canvas.DrawRect(x-5, y-5, 10, 10) ' Local matrix:=canvas.Matrix ' canvas.Matrix=matrix.Translate( x,y ).Rotate( RotationDisplay ) ' canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) ' canvas.Color = Color.Blue ' canvas.DrawRect(-5, -5, 10, 10) ' canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

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[crayon-5cba159db2435965715919 inline="true" ]Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window", Size.X, Size.Y, WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local xr:float = x + (Sin(r) * 100) Local yr:float = y + (Cos(r) * 100) canvas.DrawLine( x, y, xr, yr )   canvas.Color = Color.Blue canvas.DrawRect(x-5, y-5, 10, 10) ' Local matrix:=canvas.Matrix ' canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) ' canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) ' canvas.Color = Color.Blue ' canvas.DrawRect(-5, -5, 10, 10) ' canvas.Color = Color.Red ' canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) ' canvas.Matrix=matrix   canvas.DrawText("r = "  +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.Up) velocity.x += (Sin(r) * factor - velocity.x) * am velocity.y += (Cos(r) * factor - velocity.y) * am Elseif Keyboard.KeyDown(Key.Down) velocity.x += (-Sin(r) * factor - velocity.x) * am velocity.y += (-Cos(r) * factor - velocity.y) * am Else velocity.x *= .99 velocity.y *= .99 End If Keyboard.KeyDown(Key.Left) r += .1 End If Keyboard.KeyDown(Key.Right) r -= .1 End x += velocity.x y += velocity.y If Keyboard.KeyDown(Key.Space)then New Bullet(x, y, r) End End   End   Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = r ' Print x+" "+y+" "+r    Local gunPosX:Float = x + (Sin(r) * 100) Local gunPosY:Float = y + (Cos(r) * 100) Self.x = gunPosX Self.y = gunPosY Self.timeToLive = 40 Self.sizeW = 10 Self.sizeH = 10 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(r) * speed Local dy:Float = Cos(r) * speed x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour   canvas.DrawRect(x-5, y-5, 10, 10)   ' Local matrix:=canvas.Matrix ' canvas.Matrix=matrix.Translate( x,y ).Rotate( RotationDisplay ) ' canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) ' canvas.Color = Color.Blue ' canvas.DrawRect(-5, -5, 10, 10) ' canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

[/crayon]

The matrix stuff was making things hard for you, so I took it out so you can see the trig in operation. You can add the matrix stuff back once you get familiar with it

[JesseParticipant]

Is this what you wanted?
I marked everything I modified.
the rotation formula was wrong.

Monkey

[crayon-5cba159dbb1db546113295 inline="true" ] Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix canvas.DrawText("r = " +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = -r Local ofx:Int = 50 '************************** Local ofy:Int = 25 '************************** Local gunPosX:Float = ofx * Cos(-r+Pi/2) - ofy * Sin(-r+Pi/2) '******************** Local gunPosY:Float = ofx * Sin(-r+Pi/2) + ofy * Cos(-r+Pi/2) '******************** Self.x = x+gunPosX ' ******************** Self.y = y+gunPosY ' ******************** Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(-r) * speed '************************ Local dy:Float = Cos(-r) * speed '************************ x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate( -RotationDisplay ) '**************************** canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

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[crayon-5cba159dbb1db546113295 inline="true" ] Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = Pi / 2 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) Property RotationDisplay:Float() Return r - Pi / 2 End End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( RotationDisplay ) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix canvas.DrawText("r = "  +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = -r Local ofx:Int = 50 '************************** Local ofy:Int = 25 '**************************    Local gunPosX:Float = ofx * Cos(-r+Pi/2) - ofy * Sin(-r+Pi/2) '******************** Local gunPosY:Float = ofx * Sin(-r+Pi/2) + ofy * Cos(-r+Pi/2) '******************** Self.x = x+gunPosX ' ******************** Self.y = y+gunPosY ' ******************** Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(-r) * speed '************************ Local dy:Float = Cos(-r) * speed '************************ x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate( -RotationDisplay ) '**************************** canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

[/crayon]

[therevillsParticipant]

Thanks Guys

Yep that looks perfect Jesse – I’ve done this sort of thing before in BlitzMax but couldnt work it out! Looks like I was doing everything clockwise instead of anticlockwise, not sure about the 90 degree turn though you do (Pi / 2)?

[JesseParticipant]

Yea, I got kind of lazy and was just doing some quick modifications because of the results I was getting. I am sure you can figure out the proper way to do it. Basically the problem was in the rotation formula.

Monkey

[crayon-5cba159dd54ad072593788 inline="true" ] Local gunPosX:Float = ofx * Cos(-r+Pi/2) - ofy * Sin(-r+Pi/2) '******************** Local gunPosY:Float = ofx * Sin(-r+Pi/2) + ofy * Cos(-r+Pi/2) '********************

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[crayon-5cba159dd54ad072593788 inline="true" ]    Local gunPosX:Float = ofx * Cos(-r+Pi/2) - ofy * Sin(-r+Pi/2) '******************** Local gunPosY:Float = ofx * Sin(-r+Pi/2) + ofy * Cos(-r+Pi/2) '********************

[/crayon]

you didn’t have offy on the second line you had ofx on both sides of the formula.
Also, you forgot to add the position(x,y) of the bullet to the direction(dx,dy). about the -Pi/2, the Pi/2 is what you started off in the sprite. I am not sure I can explain it to you but you start with the sprite “Field r:Float = Pi/2” and then your RotationDisplay has an offset angle of 90 degrees. so thats why the adjustment of -Pi/2, at least that’s what I got out of it.

[EDIT]

This is more like it:

Monkey

[crayon-5cba159dd54b7002949779 inline="true" ] Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = 0 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( r) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix canvas.DrawText("r = " +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = -r Local ofx:Int = 50 Local ofy:Int = 25 Local gunPosX:Float = ofx * Cos(-r) - ofy * Sin(-r) '******************** Local gunPosY:Float = ofx * Sin(-r) + ofy * Cos(-r) '******************** Self.x = x+gunPosX Self.y = y+gunPosY Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(-r+Pi/2) * speed '************************ Local dy:Float = Cos(-r+Pi/2) * speed '************************ x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate(-r) canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

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[crayon-5cba159dd54b7002949779 inline="true" ] Namespace myapp #Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Const Size:=New Vec2i( 640,480 ) Class MyWindow Extends Window Const FPS:Int = 60 Field player:Player Field timer:Timer Method New() Super.New( "My Window",640,480,WindowFlags.Resizable ) ClearColor = Color.Black Layout="letterbox" player = New Player(100, 100) timer = New Timer(FPS, OnUpdate) End Method OnRender( canvas:Canvas ) Override player.Render(canvas) Bullet.RenderAll(canvas) End Method OnUpdate() RequestRender() player.Update() Bullet.UpdateAll() End Method OnMeasure:Vec2i() Override Return Size End End Class Sprite Field x:Float Field y:Float Field r:Float = 0 Field sizeW:Float Field sizeH:Float Field colour:Color Field velocity:Vec2f = New Vec2f(0, 0) End Class Player Extends Sprite Method New(x:Float ,y:Float) Self.x = x Self.y = y Self.sizeW = 100 Self.sizeH = 50 Self.colour = Color.Green End Method Render(canvas:Canvas ) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x ,y ).Rotate( r) canvas.DrawRect(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Color = Color.Red canvas.DrawRect((sizeW/2)-10, (sizeH/2)-10, 10, 10) canvas.Matrix=matrix canvas.DrawText("r = "  +r, 0, 0) End Method Update() Local s:Float = 2 Local am:Float = 0.08 Local factor:Float = 1.5 If Keyboard.KeyDown(Key.W) velocity.x += (1 * factor - velocity.x) * am Elseif Keyboard.KeyDown(Key.S) velocity.x += (-1 * factor - velocity.x) * am Else velocity.x *= .99 End If Keyboard.KeyDown(Key.A) r += .1 End If Keyboard.KeyDown(Key.D) r -= .1 End x += velocity.x If Keyboard.KeyHit(Key.Space) New Bullet(x, y, r) End End End Class Bullet Extends Sprite Global list := New List<Bullet> Field timeToLive:Int Field speed:Float = 5 Method New(x:Float, y: Float, r:Float) Self.x = x Self.y = y Self.r = -r Local ofx:Int = 50 Local ofy:Int = 25    Local gunPosX:Float = ofx * Cos(-r) - ofy * Sin(-r) '******************** Local gunPosY:Float = ofx * Sin(-r) + ofy * Cos(-r) '******************** Self.x = x+gunPosX Self.y = y+gunPosY Self.timeToLive = 20 Self.sizeW = 40 Self.sizeH = 15 Self.colour = Color.Red Self.list.AddLast(Self) End Function UpdateAll() If Not list Return Local it := list.All() While Not it.AtEnd Local b:Bullet = it.Current b.Update() If b.timeToLive <= 0 it.Erase() Else it.Bump() End End End Method Update() Local dx:Float = Sin(-r+Pi/2) * speed '************************ Local dy:Float = Cos(-r+Pi/2) * speed '************************ x += dx y += dy timeToLive -= 1 End Function RenderAll:Void(canvas:Canvas) If Not list Return For Local c:Bullet = Eachin list c.Render(canvas) Next End Method Render(canvas:Canvas) canvas.Color = Self.colour Local matrix:=canvas.Matrix canvas.Matrix=matrix.Translate( x,y ).Rotate(-r) canvas.DrawOval(- sizeW / 2.0, - sizeH / 2.0, sizeW, sizeH) canvas.Color = Color.Blue canvas.DrawRect(-5, -5, 10, 10) canvas.Matrix=matrix End End Function Main() New AppInstance New MyWindow App.Run() End

[/crayon]

still have to do the Pi/2 to the shoot direction. but this time its because its shooting 90 degrees from the direction it was created.

[therevillsParticipant]

Ah thanks Jesse! Yeah that makes sense!

[Author]

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