BlitImageAlphaAddColour - Learn To Code - PlayBASIC Documentation

BlitImageAlphaAddColour

BlitImageAlphaAddColour ThisImage, Xpos, Ypos, BlendColour

Parameters:

    ThisImage = The Index of the image you wish to draw
    Xpos = The X coordinate to draw this image
    Ypos = The Y coordinate to draw this image
    BlendColour = The RGB Colour to blend this surface after it's been drawn

Returns: NONE

BlitImageAlphaAddColour is similar to the DrawImage function, except it has post processing. What it does, is it draws your selected image, but it also performs a Alpha Colour Addition on the image with your selected colour. So it's the equivalent using DrawImage to first draw the image as is, then going back drawing a BOX with an AlphaAdd InkMode over the image..

The combined processing is not just to save you a few lines of code, it's actually a more optimal way of performing this action.

FACTS:

     * BlitImageAlphaAddColour alters the source image.

     * BlitImageAlphaAddColour is only intend for drawing FX or AFX formatted surfaces.

     * BlitImageAlphaAddColour doesn't support mask & alpha channel transparency.

Example Source: Download This Example

; Inlude the Blit Image functions
  #Include "BlitImage"

; Create an FX image the size of the screen
  MyImage=NewFXImage(GetScreenWidth(),GetScreenHeight())


; fill the backdrop with something so we can see it
  Tile=LoadNewFxImage("..\../Media/bg22.jpg")


  Col=$108040

  ScreenVsync on

; Start of Demo loop
  Do

     Cls 0
   ; Bump Angle, we'll use to the move the colour in a sine wave

     Angle#=WrapAngle(Angle#,1)
     ColourLevel=50+CosRadius(angle#,50)
     Colour=RGBFade(Col,ColourLevel)


   ; Draw a screen full of scrolling tiles
     RenderToImage MyImage
     TileImage Tile,Xpos,0,false
     RenderToScreen
     Xpos++

   ; Do a combined Blit (copy) our Image with Alpha Colour Addition.
   ; This lets us draw the image as is, with a while adding the colour every pixel in the image while it's being
   ; drawn, without changing the image.

     BlitImageAlphaAddColour(MyIMage,0,0,Colour)

   ; Display Message
     Ink RGB(255,0,0)

     Text 0,0,"Using BlitImageAlphaMultImage as a light Map"
     Text 0,20,"Left Mouse to change light colour"


   ; flip the back buffer to the front, so the user can see it
     Sync

  Loop


Related Info:	BlitImageAlpha50Colour \| BlitImageAlphaMultColour \| BlitImageAlphaPostMultColour \| BlitImageAlphaSubColour \| BlitImageClear \| Box \| DrawAlphaImage \| DrawImage \| InkMode :