Small Basic Sample: GameGraphics
Code
Import to Small Basic : XZG681-11
'***************************************************************************************
'Sample program to demonstate virtually all of the SmallBasic GraphicsWindow commands
'Includes use of Shapes, Images, Arrays, Mouse and Keyboard control
'Does all of the main features required to write games using basic examples
'You will need to look at the code to see what is supposed to happen and how it is done
'Play with it, change it, break it then fix it
'***************************************************************************************
'
'Create a graphics window
'
'Keep it hidden till we want to show it
GraphicsWindow.Hide()
'Give it a title
GraphicsWindow.Title = "Graphics Window Example"
'Set its size and position (use variables gw and gh because they may be useful later)
gw = 800
gh = 600
GraphicsWindow.Width = gw
GraphicsWindow.Height = gh
'The top and left = 4 position the window neatly in the top left of the screen
GraphicsWindow.Top = 4
GraphicsWindow.Left = 4
'Set a background colour
GraphicsWindow.BackgroundColor = "LightBlue"
'Set it so it cannot be resized
GraphicsWindow.CanResize = "False"
'Show the window
GraphicsWindow.Show()
'Goto end
'
'Create a red ball of diameter 50 (radius 25) and place it in the middle of the window (leave it there for 5 seconds)
'
radius = 25
GraphicsWindow.BrushColor = "Red"
GraphicsWindow.PenColor = "Black"
' We set the position to be the (screen centre - radius), since the screen position is defined as the top left of the ball
ball = Shapes.AddEllipse(2*radius,2*radius)
Shapes.Move(ball,gw/2-radius,gh/2-radius)
Program.Delay(5000) ' 5000 milliseconds = 5 seconds
'
'Move the ball randomly by animation 10 times (once per second)
'
For i = 1 To 10
x = Math.GetRandomNumber(gw)
y = Math.GetRandomNumber(gh)
Shapes.Animate(ball,x-radius,y-radius,1000)
Program.Delay(1000) ' We have to delay (pause) to wait for the animation to finish
EndFor
'
'Move the ball to follow the mouse for 10 seconds
'
start = Clock.Second
time = 0
While (time < 10)
xm = GraphicsWindow.MouseX
ym = GraphicsWindow.MouseY
Shapes.Move(ball,xm-radius,ym-radius)
time = Clock.Second - start
'If we go over the minute then seconds go back to 0 so add 60 seconds
If (time < 0) Then
time = time+60
EndIf
'Display the mouse coordinates - first overwrite the last output
GraphicsWindow.PenColor = GraphicsWindow.BackgroundColor
GraphicsWindow.BrushColor = GraphicsWindow.BackgroundColor
GraphicsWindow.FillRectangle(gw-120,10,120,30)
GraphicsWindow.BrushColor = "Black"
GraphicsWindow.FontSize = 20
GraphicsWindow.DrawText(gw-120,10,"("+xm+","+ym+")")
EndWhile
'
'Use 10 balls and move the one selected by the mouse left down (delete with right down)
'Run until all balls are deleted
'The moved balls change colour
'
GraphicsWindow.Clear()
'Create an array of 10 balls and their random positions
nball = 10
For i = 1 To nball
GraphicsWindow.BrushColor = "LightGreen"
GraphicsWindow.PenColor = "Black"
x[i] = radius + Math.GetRandomNumber(gw-2*radius)
y[i] = radius + Math.GetRandomNumber(gh-2*radius)
ball = Shapes.AddEllipse(2*radius,2*radius)
Shapes.Move(ball,x[i]-radius,y[i]-radius)
balls[i] = ball
EndFor
start = Clock.Second
iball = 0
While (nball > 0)
If (Mouse.IsLeftButtonDown = "True") Then
xm = GraphicsWindow.MouseX
ym = GraphicsWindow.MouseY
'If no ball selected, then check if we are over one
If (iball = 0) Then
For i = 1 To nball
If (xm >= x[i]-radius And xm <= x[i]+radius And ym >= y[i]-radius And ym <= y[i]+radius) Then
iball = i
'To change the colour we delete it and replace it with a new ball
GraphicsWindow.BrushColor = "Pink"
Shapes.Remove(balls[iball])
balls[iball] = Shapes.AddEllipse(2*radius,2*radius)
'We are finished and don't want to continue checking since we have already deleted a ball so end this loop
Goto completed1
EndIf
EndFor
EndIf
completed1:
'Move selected ball
If (iball > 0) Then
ball = balls[iball]
x[iball] = xm
y[iball] = ym
Shapes.Move(ball,x[iball]-radius,y[iball]-radius)
EndIf
Else
'drop current ball
iball = 0
EndIf
'Delete a ball with right click
If (Mouse.IsRightButtonDown = "True") Then
xm = GraphicsWindow.MouseX
ym = GraphicsWindow.MouseY
For i = 1 To nball
If (xm >= x[i]-radius And xm <= x[i]+radius And ym >= y[i]-radius And ym <= y[i]+radius) Then
'Remove the displayed object
Shapes.Remove(balls[i])
'Now remove the array element i - we do this by overwriting it with the balls further up the array
For j = i To nball-1
balls[j] = balls[j+1]
x[j] = x[j+1]
y[j] = y[j+1]
EndFor
'Delete the last ball (now moved up the array 1 place)
balls[nball] = ""
x[nball] = ""
y[nball] = ""
'Reduce the count of balls
nball = nball-1
'We are finished and don't want to continue checking since we have already deleted a ball so end this loop
Goto completed2
EndIf
EndFor
EndIf
completed2:
EndWhile
'
'Replace the ball with an image and move with arrow keys for 20 seconds
'
'Delete the last ball and set a new one as a downloaded image - get its radius
GraphicsWindow.Clear()
image = ImageList.LoadImage("http://icons.iconarchive.com/icons/icons-land/metro-raster-sport/64/Soccer-Ball-icon.png")
ball = Shapes.AddImage(image)
radius = ImageList.GetWidthOfImage(image)/2
'Set variables to say if keys are pressed or not
keyLeft = 0
keyRight = 0
keyUp = 0
keyDown = 0
'Start an event for keydown and keyup
GraphicsWindow.KeyDown = OnKeyDown
GraphicsWindow.KeyUp = OnKeyUp
'Use the event to set the keypress flags - these are only called when a key is pressed or released
Sub OnKeyDown
key = GraphicsWindow.LastKey
If (key = "Left") Then
keyLeft = 1
ElseIf (key = "Right") Then
keyRight = 1
ElseIf (key = "Up") Then
keyUp = 1
ElseIf (key = "Down") Then
keyDown = 1
EndIf
EndSub
Sub OnKeyUp
key = GraphicsWindow.LastKey
If (key = "Left") Then
keyLeft = 0
ElseIf (key = "Right") Then
keyRight = 0
ElseIf (key = "Up") Then
keyUp = 0
ElseIf (key = "Down") Then
keyDown = 0
EndIf
EndSub
'Start in window centre
x = gw/2
y = gh/2
start = Clock.Second
time = 0
While (time < 20)
'Update position if a key is currently down
If (keyLeft = 1) Then
x = x-1
EndIf
If (keyRight = 1) Then
x = x+1
EndIf
If (keyUp = 1) Then
y = y-1 ' The pixes for the window increase downwards from the top
EndIf
If (keyDown = 1) Then
y = y+1
EndIf
'Check for ball leaving screen - reneter other side
If (x < 0) Then
x = gw
EndIf
If (x > gw) Then
x = 0
EndIf
If (y < 0) Then
y = gh
EndIf
If (y > gh) Then
y = 0
EndIf
'Move the ball to the new position
Shapes.Move(ball,x-radius,y-radius)
'Put a small delay in - the computer is too quick - this controls the update rate (frames per second)
'This is not the true fps since it doesn't account for the time drawing etc
fps = 500
Program.Delay(1000/fps)
time = Clock.Second - start
'If we go over the minute then add 60 seconds
If (time < 0) Then
time = time+60
EndIf
EndWhile
'
'Now use the arrow keys to accelerate the ball and run until 50 wall hits (almost the same code)
'We can use the keyboard events unchanged
'Reverse spin the ball when we hit a boundary
'
'Start in window centre
x = gw/2
y = gh/2
'Zero initial velocity
u = 0
v = 0
start = Clock.Second
spin = 0.0 'Ball spin rate (Positive is anticlockwise)
angle = 0
hits = 0
While (hits < 50)
'Update position if a key is currently down
If (keyLeft = 1) Then
u = u-1
EndIf
If (keyRight = 1) Then
u = u+1
EndIf
If (keyUp = 1) Then
v = v-1 ' The pixes for the window increase downwards from the top
EndIf
If (keyDown = 1) Then
v = v+1
EndIf
'Update position - divide by 500 to stop the acceleration being too extreme
'we can do gravity, friction etc here if we want
x = x+u/500
y = y+v/500
'Check for ball leaving screen - bounce the ball this time - and spin it
If (x < radius) Then
u = -u
spin = spin+v
hits = hits+1
EndIf
If (x > gw-radius) Then
u = -u
spin = spin-v
hits = hits+1
EndIf
If (y < radius) Then
v = -v
spin = spin-u
hits = hits+1
EndIf
If (y > gh-radius) Then
v = -v
spin = spin+u
hits = hits+1
EndIf
'Move the ball to the new position
Shapes.Move(ball,x-radius,y-radius)
'Rotate the ball with the current spin direction
Shapes.Rotate(ball,angle)
angle = angle+0.001*spin
'Put a small delay in - the computer is too quick - this controls the update rate (frames per second)
'This is not the true fps since it doesn't account for the time drawing etc
fps = 500
Program.Delay(1000/fps)
EndWhile
'
'Create an array of 10 randomly sized and coloured rotating boxes, then delete them when clicked with the mouse
'
GraphicsWindow.Clear()
'Create arrays of boxes and their positions and sizes
For i = 1 To 10
x[i] = 20+Math.GetRandomNumber(gw-60) ' not too close the the screen edge
y[i] = 20+Math.GetRandomNumber(gh-60)
w[i] = 10+Math.GetRandomNumber(30)
h[i] = 10+Math.GetRandomNumber(30)
GraphicsWindow.BrushColor = GraphicsWindow.GetRandomColor()
GraphicsWindow.PenColor = "Black"
box = Shapes.AddRectangle(w[i],h[i])
'Note x[i],y[i] are top left of box, not its centre
Shapes.Move(box,x[i],y[i])
boxes[i] = box
display[i] = 1 ' flag that box is displayed
EndFor
'Start a mouse click event
GraphicsWindow.MouseDown = OnMouseDown
'Write the mouse click event to get coordinates of mouse click and set a flag that the mouse was clicked
clicked = 0
Sub OnMouseDown
xm = GraphicsWindow.MouseX
ym = GraphicsWindow.MouseY
clicked = 1
EndSub
'Continue while boxes remain
nboxes = Array.GetItemCount(boxes)
angle = 0
While (nboxes > 0)
'Mouse was clicked
If (clicked = 1) Then
'Check each box
For i = 1 To Array.GetItemCount(boxes)
'Only look for remaining displayed boxes
If (display[i] = 1) Then
box = boxes[i]
'Since the boxes are rotating use the maximum size to check for click region
'This is not exactly correct for rotating boxes but often in games efficient is more important than absolute correctness
dmax = Math.Max(w[i],h[i])
If (xm >= x[i] And xm <= x[i]+dmax And ym >= y[i] And ym <= y[i]+dmax) Then
'Delete this box from display and reduce the box count by 1
'Note the original arrays are not deleted since we are keeping track of box status using display[i]
Shapes.Remove(box)
nboxes = nboxes-1
display[i] = 0
Sound.PlayClick()
EndIf
EndIf
EndFor
'Reset clicked flag to off since we have done everything with it
clicked = 0
EndIf
'Rotate the boxes (even i anticlockwise, odd i clockwise - negative angle)
For i = 1 To Array.GetItemCount(boxes)
If (display[i] = 1) Then
box = boxes[i]
Shapes.Rotate(box,angle*(1-2*Math.Remainder(i,2)))
EndIf
EndFor
angle = angle+1
Program.Delay(10) ' Small delay to keep the rotation smooth
EndWhile
'
'Finish up
'
end:
image = ImageList.LoadImage("http://www.windowswiki.info/wp-content/uploads/smallbasic_logo.png")
GraphicsWindow.Clear()
GraphicsWindow.FontSize = 100
GraphicsWindow.FontBold = "True"
GraphicsWindow.FontName = "Rockwell"
GraphicsWindow.DrawResizedImage(image,0,0,gw,gh)
R = 255
G = 0
B = 0
dR = -1
dG = 2
dB = 3
clicked = 0
While (clicked = 0)
'Change the red, green, blue components of the colour at different rates to get changing colours
If (R < 0 Or R > 255) Then
dR = -dR
R = R+dR
EndIf
If (G < 0 Or G > 255) Then
dG = -dG
G = G+dG
EndIf
If (B < 0 Or B > 255) Then
dB = -dB
B = B+dB
EndIf
colour = GraphicsWindow.GetColorFromRGB(R,G,B)
GraphicsWindow.BrushColor = colour
GraphicsWindow.DrawText(200,160,"All Done")
GraphicsWindow.DrawText(100,340,"Click to Exit")
GraphicsWindow.PenWidth = 10
GraphicsWindow.PenColor = colour
GraphicsWindow.DrawLine(50,gh-50,gw-50,gh-50)
GraphicsWindow.DrawLine(gw-50,gh-50,gw-50,50)
GraphicsWindow.DrawLine(gw-50,50,50,50)
GraphicsWindow.DrawLine(50,50,50,gh-50)
R = R+dR
G = G+dG
B = B+dB
Program.Delay(20)
EndWhile
Program.End()