The graphics module provides the ability to create and 'flip' graphics objects.
A graphics object represents a rectangular area you can render to. However, the graphics module
does not provide any commands for actual rendering - this is left to other modules such as
max2D to implement.
The graphics module maintains 2 'current' objects - the current graphics driver and the currect
graphics object. To change the current graphics driver, use SetGraphicsDriver. To change the
current graphics object, use SetGraphics.
To create a graphics object, use either Graphics or CreateGraphics. The kind of graphics
object created will depend upon the current graphics driver. For example, the following code:
SetGraphicsDriver GLGraphicsDriver()
Local g:TGraphics=CreateGraphics( 640,480,32,60,GRAPHICS_BACKBUFFER )
Will create an OpenGL graphics object.
You can 'select' this object for rendering using:
SetGraphics g 'we can now execute OpenGL code
glClearColor .5,0,1,1 'tada!
glClear 'yes!
Flip 'must do this as the graphics is double buffered
One you have finished with a graphics object, use CloseGraphics to close it.
Graphics and CreateGraphics both accept the following parameters: width, height, depth,
hertz and flags.
The width and height parameters specify the dimensions of the graphics, in pixels.
The depth parameter selects a pixel bit depth. This value can be 0, 16, 24 or 32 depending
on the graphics modes available. A depth of 0 can be used to select 'windowed mode' graphics,
while non-0 depths select 'fullscreen' graphics.
The hertz parameter selects a refresh rate, which refers to the number of times the screen
refreshes per second. The refresh rates available depend on the graphics modes available,
which differ from graphics card to graphics card. Note that creating graphics with an
unsupported refresh rate will not fail - instead, a default refresh rate will be used.
The Graphics command can be used to achieve a fixed refresh rate. When using Flip to
present such graphics, BlitzMax will guarantee the desired refresh rate is honored regardless
of the available hardware's capabilities. This is achieved by using software timing
techniques when necessary.
The flags parameter can be any combination of the following:
Flags | Meaning |
GRAPHICS_BACKBUFFER | Create graphics with a back buffer |
GRAPHICS_ALPHABUFFER | Create graphics with an alpha buffer |
GRAPHICS_DEPTHBUFFER | Create graphics with a depth buffer |
GRAPHICS_STENCILBUFFER | Create graphics with a stencil buffer |
GRAPHICS_ACCUMBUFFER | Create graphics with an accumulation buffer |
Flags can be combined with the | (or) operator. For example, GRAPHICS_BACKBUFFER|GRAPHICS_DEPTHBUFFER
can be used to create graphics which has both a back buffer and a depth buffer.
Graphics created with the GRAPHICS_BACKBUFFER flag must be 'flipped' after you have finished
rendering using Flip.
Globals
Functions
Global reference
Global FlipHook=AllocHookId() |
Description | Flip Hook id |
Information |
Use this id with AddHook to register a function that
is called every Flip.
|
Function reference
Function SetGraphicsDriver( driver:TGraphicsDriver,defaultFlags=GRAPHICS_BACKBUFFER ) |
Description | Set current graphics driver |
Information |
The current graphics driver determines what kind of graphics are created when you use
the CreateGraphics or Graphics functions, as well as the graphics modes available.
The GLGraphicsDriver, GLMax2DDriver, D3D7Max2DDriver and D3D9Max2DDriver functions can all be
used to obtain a graphics driver.
The defaultFlags parameter allows you to specify graphics flags that will be applied to any
graphics created with CreateGraphics or Graphics.
|
Example | SetGraphicsDriver GLMax2DDriver()
Graphics 640,480
DrawText "OpenGL Max2D Graphics! Hit any key (next to the whatever key)...",0,0
Flip
WaitKey
EndGraphics
SetGraphicsDriver GLGraphicsDriver()
Graphics 640,480
glClear GL_COLOR_BUFFER_BIT
GLDrawText "'Raw' OpenGL Graphics! Hit any key...",0,0
Flip
WaitKey
|
Function GetGraphicsDriver:TGraphicsDriver() |
Description | Get current graphics driver |
Information |
Returns the current graphics driver as selected by SetGraphicsDriver
|
Function DefaultGraphicsFlags() |
Description | Get current default graphics flags |
Function GraphicsModes:TGraphicsMode[]() |
Returns | An array of TGraphicsMode objects
|
Description | Get graphics modes available under the current graphics driver |
Information |
A TGraphicsMode object contains the following fields: width, height, depth and hertz
|
Example | Print "Available graphics modes:"
For mode:TGraphicsMode=EachIn GraphicsModes()
Print mode.width+","+mode.height+","+mode.depth+","+mode.hertz
Next
|
Function CountGraphicsModes() |
Returns | Number of available Graphics modes
|
Description | Get number of graphics modes available under the current graphics driver |
Information |
Use GetGraphicsMode To obtain information about an individual Graphics mode
|
Function GetGraphicsMode( index,width Var,height Var,depth Var,hertz Var ) |
Description | Get information about a graphics mode |
Information |
GetGraphicsMode returns information about a specific graphics mode. mode should be
in the range 0 (inclusive) to the value returned by CountGraphicsModes (exclusive).
|
Function GraphicsModeExists( width,height,depth=0,hertz=0 ) |
Returns | True if a matching graphics mode is found
|
Description | Determine if a graphics mode exists |
Information |
A value of 0 for any of width, height, depth or hertz will cause that
parameter to be ignored.
|
Function CreateGraphics:TGraphics( width,height,depth,hertz,flags ) |
Returns | A graphics object
|
Description | Create a graphics object |
Information |
CreateGraphics creates a graphics object. To use this object for rendering, you will
first have to select it using SetGraphics.
The kind of graphics object returned depends upon the current graphics driver as set by
SetGraphicsDriver.
|
Function CloseGraphics( g:TGraphics ) |
Description | Close a graphics object |
Information |
Once closed, a graphics object can no longer be used.
|
Function SetGraphics( g:TGraphics ) |
Description | Set current graphics object |
Information |
SetGraphics will also change the current graphics driver if g uses a different driver
than the current driver.
|
Function GraphicsWidth() |
Returns | The width, in pixels, of the current graphics object
|
Description | Get width of current graphics object |
Information |
The current graphics object can be changed using SetGraphics.
|
Function GraphicsHeight() |
Returns | The height, in pixels, of the current graphics object
|
Description | Get height of current graphics object |
Information |
The current graphics object can be changed using SetGraphics.
|
Function GraphicsDepth() |
Returns | The depth, in bits, of the current graphics object
|
Description | Get depth of current graphics object |
Information |
The current graphics object can be changed using SetGraphics.
|
Function GraphicsHertz() |
Returns | The refresh rate, in frames per second, of the current graphics object
|
Description | Get refresh rate of current graphics object |
Information |
The current graphics object can be changed using SetGraphics.
|
Function GraphicsFlags() |
Returns | The flags of the current graphics object
|
Description | Get flags of current graphics object |
Information |
The current graphics object can be changed using SetGraphics.
|
Function Flip( sync=-1 ) |
Description | Flip current graphics object |
Information |
Flip swap the front and back buffers of the current graphics objects.
If sync is 0, then the flip occurs as soon as possible. If sync is 1, then the flip occurs
on the next vertical blank.
If sync is -1 and the current graphics object was created with the Graphics command,
then flips will occur at the graphics object's refresh rate, unelss the graphics object was
created with a refresh rate of 0 in which case flip occurs immediately.
If sync is -1 and the current graphics object was NOT created with the Graphics command,
then the flip will occur on the next vertical blank.
|
Function Graphics:TGraphics( width,height,depth=0,hertz=60,flags=0 ) |
Returns | A graphics object
|
Description | Begin graphics |
Information |
Graphics is a convenience function that simplifies the process of creating a graphics
object.
Once Graphics has executed, you can begin rendering immediately without any need for
SetGraphics.
Graphics also enables polled input mode, providing a simple way to monitor the keyboard
and mouse.
|
Function EndGraphics() |
Description | End graphics |
Information |
EndGraphics closes the graphics object returned by Graphics.
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