Target Renderer
This article describes data structures. 
Concepts illustrated in this article are relevant to be able to understand what kind of data FIFE engine is able to process.
Introduction
In previous version of FIFE you were allowed to draw on image just as on back buffer but it was far from optimal. Since 0.3.3 this is not possible anymore. Instead, we introduced Target Renderer to do it from now on. When using OpenGL render backend, it uses internally FBO or fallbacks to drawing on backbuffer and copying it to a destination when FBO isn't supported. With SDL, it just replace blitting destination for given image surface.
Usage
In order to make use of it you need to create render target and link it with an image:
image = imagemanager.load(image_file_path) rendertarget = targetrenderer.createRenderTarget(image)
When you require to use it as a render target you simply call:
targetrenderer.setRenderTarget(image_file_path, discard=False, ndraws=0)
- discard
- tells FIFE that you care about previous contents of the image. If you want to just add something to already non trivial image you should set it to False. Otherwise, when you need to redraw whole image, you should set it to True.
- ndraws
- tells FIFE how frequently it should draw with ndraws=0 meaning just for the next frame, ndraws=1 means every frame, ndraws=2 means every other frame and so on. This option can be useful if you don't need to recreate/redraw an image every frame, like for instance the minimap image - only on change.
Drawing is done in the same way as with GenericRenderer.
Options
TargetRenderer
createRenderTarget(group, width, height)
returns a RenderTarget (image) with the given name and size
- group
- string; the group name
- width
- integer; width
- height
- integer; height
createRenderTarget((image)
returns a RenderTarget (image) based on the given image pointer, so you can render on already loaded / created images
- image
- fife.ImagePtr; image pointer
setRenderTarget(targetname, discard, ndraws)
sets a RenderTarget that is used by the TargetRenderer
- targetname
- string; target name
- discard
- bool; discard the content of the image or not
- ndraws
- integer; frequency of draws (0: only next frame, 1: every frame, 2: every other frame...)
render()
forces the target to render, should not be used as the engine calls this
RenderTarget
addLine(group, n1, n2, r, g, b, a = 255)
adds a line to the target
- group
- string; the group name
- n1, n2
- fife.Point objects; screen coordinates
- r,g,b,(a)
- integer; color values, range 0-255
addPoint(group, n, r, g, b, a = 255)
adds a point (pixel) to the target
- group
- string; the group name
- n
- fife.Point objects; screen coordinates
- r,g,b,(a)
- integer; color values, range 0-255
addTriangle(group, n1, n2, n3, r, g, b, a = 255)
adds a triangle to the target
- group
- string; the group name
- n1, n2, n3
- fife.Point objects; screen coordinates
- r,g,b,(a)
- integer; color values, range 0-255
addQuad(group, n1, n2, n3, n4, r, g, b, a = 255)
adds a quad to the target
- group
- string; the group name
- n1, n2, n3, n4
- fife.Point objects; screen coordinates
- r,g,b,(a)
- integer; color values, range 0-255
addVertex(group, n, size, r, g, b, a = 255)
adds a vertex (frame) to the target
- group
- string; the group name
- n
- fife.Point object; center coordinate
- size
- integer; dimensions
- r,g,b,(a)
- integer; color values, range 0-255
addText(group, n, font, text)
adds a text to the target
- group
- string; the group name
- n
- fife.Point object; center coordinate
- font
- fife.IFont; pointer to font object
- text
- string; a text
addImage(group, n, image)
adds another image to the target
- group
- string; the group name
- n
- fife.Point object; center coordinate
- image
- fife.ImagePtr; pointer to the image
addAnimation(group, n, animation)
adds an animation to the target
- group
- string; the group name
- n
- fife.Point object; center coordinate
- animation
- fife.AnimationPtr; pointer to the animation
resizeImage(group, n, image, width, height)
adds another image in a different size to the target
- group
- string; the group name
- n
- fife.Point object; center coordinate
- image
- fife.ImagePtr; pointer to the image
- width
- integer; new width
- height
- integer; new height
removeAll(group)
removes all elements of the given group
- group
- string; the group name
removeAll()
removes everything
render()
forces the target to render, should not be used as the engine calls this
getTarget()
returns the target image
Example
Here we create a new RenderTarget with width=200, height=200. Then we add a red quad on it and let the GenericRenderer draws it on screen.
# self.hero.instance is an instance of fife.Instance() # self.camera is an instance of fife.Camera() #get renderer target_renderer = self.engine.getTargetRenderer() generic_renderer = fife.GenericRenderer.getInstance(self.camera) #create and set target target = target_renderer.createRenderTarget("testimage.png", 200, 200) target_renderer.setRenderTarget("testimage.png", True, 0) #add quad target.addQuad("quads", fife.Point(0,100), fife.Point(100,100), fife.Point(100,0), fife.Point(0,0), 255, 0, 0) #create node node = fife.RendererNode(self.hero.instance) #add target to generic generic_renderer.addImage("quad_test", node, target.getTarget())
