Unit TFT Framebuffer
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Description
Ultibo TFT Framebuffer Driver Library unit
This is a generic framebuffer device support unit for SPI based TFT screens using common chipsets.
This unit implements the shared functionality that is common to all devices and provides a set of functions that device specific drivers must implement. For each supported device a driver unit is required that implements the SPI communications to initialize the device, setup resolution and color depth as well as refreshing the framebuffer data to the device memory on change.
The resulting device created by the combination of this unit and a device specific driver is registered with Ultibo as a framebuffer device that can be accessed using all of the standard framebuffer API functions.
For examples of drivers that use this support unit see the HX8357D and ILI9340 units.
Constants
TFT_FRAMEBUFFER_* TFT_FRAMEBUFFER_FRAME_RATE_DEFAULT = 20;
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Default frame rate of 20 frames per second refresh |
Type definitions
TFT framebuffer initialize
TTFTFramebufferInitialize = function(Framebuffer:PTFTFramebuffer; Defaults:PFramebufferProperties):LongWord;
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TFT framebuffer deinitialize
TTFTFramebufferDeinitialize = function(Framebuffer:PTFTFramebuffer):LongWord;
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TFT framebuffer get defaults
TTFTFramebufferGetDefaults = function(Framebuffer:PTFTFramebuffer; Properties,Defaults:PFramebufferProperties):LongWord;
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TFT framebuffer set write address
TTFTFramebufferSetWriteAddress = function(Framebuffer:PTFTFramebuffer; X1,Y1,X2,Y2:LongWord):LongWord;
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TFT framebuffer write memory
TTFTFramebufferWriteMemory = function(Framebuffer:PTFTFramebuffer; Address:PtrUInt; Size:LongWord):LongWord;
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TFT framebuffer device
PTFTFramebuffer = ^TTFTFramebuffer;
TTFTFramebuffer = record
| Framebuffer Properties | |
Framebuffer:TFramebufferDevice;
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| TFT Properties | |
SPI:PSPIDevice;
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The SPI device this Framebuffer is connected to |
ChipSelect:Word;
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The SPI chip select of the device |
RST:TGPIOInfo;
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The GPIO information for the reset line |
DC:TGPIOInfo;
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The GPIO information for the data/command line |
BL:TGPIOInfo;
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The GPIO information for the backlight line |
Initialize:TTFTFramebufferInitialize;
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A device specific Initialize method (Optional) |
Deinitialize:TTFTFramebufferDeinitialize;
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A device specific Deinitialize method (Optional) |
GetDefaults:TTFTFramebufferGetDefaults;
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A device specific GetDefaults method (Mandatory) |
SetWriteAddress:TTFTFramebufferSetWriteAddress;
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A device specific SetWriteAddress method (Mandatory) |
WriteMemory:TTFTFramebufferWriteMemory;
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A device specific WriteMemory method (Mandatory) |
| Driver Properties | |
Width:LongWord;
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Framebuffer Width in Pixels |
Height:LongWord;
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Framebuffer Height in Pixels |
Rotation:LongWord;
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Framebuffer Rotation (eg FRAMEBUFFER_ROTATION_180) |
DirtyY1:LongWord;
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First line of dirty region (or Height - 1 if none dirty) |
DirtyY2:LongWord;
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Last line of dirty region (or 0 if none dirty) |
Ready:LongBool;
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If True timer should be enabled during Mark operation |
Lock:TMutexHandle;
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Lock for dirty region redraw |
Timer:TTimerHandle;
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Handle for dirty region redraw timer |
FrameRate:LongWord;
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Frame rate for display refresh (in Frames Per Second) |
TransferSize:LongWord;
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Maximum transfer size for the SPI device (or -1 if No Maximum) |
Public variables
None defined
Function declarations
TFT framebuffer functions
function TFTFramebufferAllocate(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;
| Note | Not intended to be called directly by applications, use FramebufferDeviceAllocate instead. |
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function TFTFramebufferRelease(Framebuffer:PFramebufferDevice):LongWord;
| Note | Not intended to be called directly by applications, use FramebufferDeviceRelease instead. |
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function TFTFramebufferMark(Framebuffer:PFramebufferDevice; X,Y,Width,Height,Flags:LongWord):LongWord;
| Note | Not intended to be called directly by applications, use FramebufferDeviceMark instead.
Marks full lines only, X and Width are ignored for TFT Framebuffer. |
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function TFTFramebufferCommit(Framebuffer:PFramebufferDevice; Address:PtrUInt; Size,Flags:LongWord):LongWord;
| Note | Not intended to be called directly by applications, use FramebufferDeviceCommit instead. |
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procedure TFTFramebufferUpdateDisplay(Framebuffer:PTFTFramebuffer);
| Note | Not intended to be called directly by applications |
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