RFC: GUIGraphicsDriver

BlitzMax Forums/MaxGUI Module/RFC: GUIGraphicsDriver

UByte

(Posted 2009) [#1]

At the moment MaxGUI apps are restricted to using OpenGL/DirectX for rendering to canvases. For me this is an unnecessary overhead and breaks the look and feel of the underlying OS (for example fonts are not rendered with sub-pixel accuracy a.k.a ClearType with Max2D.)

It is entirely possible to write a graphics driver to abstract the OS's native UI drawing functions. The framework I am proposing/using is presented below, it is inspired by Java's awt.Graphics API. Notable features are:

-Ability to select a GUIFont directly into the graphics context.
-Ability to acquire the font metrics for a given GUIFont
-A native Image Class for accelerated bitmap drawing (as well as pixmaps and argb data)
-Typical primitives.
-Clipping API.
-Origin Translation.

I'm Currently working on GUIDrivers for Win32 GDI and FLTK for Linux.

I'd appreciate anyone's thoughts and suggestions on this topic. Especially anyone who would attempt a MacOSX or GTK driver.

Type TGUIImage
	Method GetWidth:Int() Abstract
	Method GetHeight:Int() Abstract
	Method IsMutable:Int() Abstract
	Method GetGraphics:Int() Abstract
	Method GetRGB(rgbData:Int Ptr, scanlength:Int, x:Int, y:Int, width:Int, height:Int) Abstract
End Type

Type TGUIFontMetrics
	Method GetFont:TGUIFont() Abstract
	Method GetHeight:Int() Abstract
	Method GetAscent:Int() Abstract
	Method GetDescent:Int() Abstract
	Method GetLeading:Int() Abstract
	Method StringWidth:Int(str:String) Abstract
End Type


Type TGUIGraphics Extends TGraphics

	' Primitives
	Method ClearRect(x:Int, y:Int, width:Int, height:Int) Abstract
	Method DrawLine(x1:Int, y1:Int, x2:Int, y2:Int) Abstract
	Method DrawArc(x:Int, y:Int, width:Int, height:Int, startAngle:Int, arcAngle:Int) Abstract
	Method FillArc(x:Int, y:Int, width:Int, height:Int, startAngle:Int, arcAngle:Int) Abstract
	Method DrawOval(x:Int, y:Int, width:Int, height:Int) Abstract
	Method FillOval(x:Int, y:Int, width:Int, height:Int) Abstract
	Method DrawRect(x:Int, y:Int, width:Int, height:Int) Abstract
	Method FillRect(x:Int, y:Int, width:Int, height:Int) Abstract
	Method DrawRoundRect(x:Int, y:Int, width:Int, height:Int, arcWidth:Int, arcHeight:Int) Abstract
	Method FillRoundRect(x:Int, y:Int, width:Int, height:Int, arcWidth:Int, arcHeight:Int) Abstract
	Method DrawPolyline(xPoints:Int Ptr, yPoints:Int Ptr, nPoints:Int, stride:Int=1) Abstract
	Method DrawPolygon(xPoints:Int Ptr, yPoints:Int Ptr, nPoints:Int, stride:Int=1) Abstract
	Method FillPolygon(xPoints:Int Ptr, yPoints:Int Ptr, nPoints:Int, stride:Int=1) Abstract	
	
	' Images
	Method DrawImage(img:TGUIImage, x:Int, y:Int) Abstract
	Method DrawImageRect(img:TGUIImage, x_src:Int, y_src:Int, width:Int, height:Int, x_dest:Int, y_dest:Int) Abstract
	Method DrawRGB(argb:Int Ptr, scanlength:Int, x:Int, y:Int, width:Int, height:Int, processAlpha:Int=1) Abstract
	Method DrawPixmap(pix:TPixmap, x:Int, y:Int, processAlpha:Int=1) Abstract
	
	' Font/Text
	Method SetFont(font:TGUIFont) Abstract
	Method GetFont:TGUIFont() Abstract
	Method GetFontMetrics:TGUIFontMetrics() Abstract
	Method DrawString(str:String, x:Int, y:Int) Abstract
	
	' State
	Method SetColor(r:Int, g:Int, b:Int) Abstract
	Method GetColor(r:Int Var, g:Int Var, b:Int Var) Abstract
	Method ClipRect(x:Int, y:Int, width:Int, height:Int) Abstract
	Method SetClip(x:Int, y:Int, width:Int, height:Int) Abstract
	Method GetClip(x:Int Var, y:Int Var, width:Int Var, height:Int Var) Abstract
	Method HitClip:Int(x:Int, y:Int, width:Int, height:Int) Abstract
	Method Translate(x:Int, y:Int) Abstract
	Method SetTranslation(x:Int Var, y:Int Var) Abstract
	Method GetTranslation(x:Int Var, y:Int Var) Abstract
	
	' BRL.Graphics
	Method Driver:TGraphicsDriver() Abstract
	Method GetSettings(width:Int Var,height:Int Var,depth:Int Var,hertz:Int Var,flags:Int Var) Abstract
	Method Close() Abstract
	
End Type

Type TGUIGraphicsDriver Extends TGraphicsDriver

	Method CreateImage:TGUIImage(width:Int, height:Int) Abstract
	Method CreateRGBImage:TGUIImage(argb:Int Ptr, scanlength:Int, width:Int, height:Int, processAlpha:Int) Abstract
	Method CreatePixmapImage:TGUIImage(pixmap:TPixmap, processAlpha:Int=1) Abstract
	
	'BRL.Graphics Driver
	Method GraphicsModes:TGraphicsMode[]() Abstract
	Method AttachGraphics:TGraphics(widget:Int,flags:Int) Abstract
	Method CreateGraphics:TGraphics(width:Int,height:Int,depth:Int,hertz:Int,flags:Int) Abstract
	Method SetGraphics(g:TGraphics) Abstract
	Method Flip(sync:Int) Abstract
	
End Type

Brucey

(Posted 2009) [#2]

Since you can do all this in wxMax, there's no reason not to do it in MaxGUI too :-)

UByte

(Posted 2009) [#3]

Yes there is...

because I can :)

Edit: Oops misunderstood :s

GaryV

(Posted 2009) [#4]

I'm Currently working on GUIDrivers for Win32 GDI

Very interested :)

SebHoll

(Posted 2009) [#5]

Hi,

Just saw this topic and it looks very interesting. Have you managed to get very far with it?

UByte

(Posted 2009) [#6]

Glad there's some interest at least.

Will have to get my arse in gear and do a proof of concept soon. Been somewhat distracted. In fact I'll flesh out the GDI module over the next couple of evenings and hopefully have something ready on Monday.

EOF	(Posted 2009) [#7]

I had a dabble in GUI graphics before. The only thing I could not figure out is how to implement image rotation and alpha
Also, how to load mage fformats other than BMP