lcd.h File Reference

Functions for interacting with the LCD and VRAM. More...

#include <stdint.h>

Include dependency graph for lcd.h:

Go to the source code of this file.

Macros
#define	__UCONCAT(a, b)   #a b
#define	_UCONCAT(a, b)   __UCONCAT(a, b)
#define	UCONCAT(b)   _UCONCAT(__USER_LABEL_PREFIX__, b)
#define	RGB_TO_RGB565(r, g, b)
#define	RGB565_TO_R(rgb565)   ((rgb565 >> 11) & 0x1F)
#define	RGB565_TO_G(rgb565)   ((rgb565 >> 5) & 0x3F)
#define	RGB565_TO_B(rgb565)   (rgb565 & 0x1F)

Enumerations
enum	LCD_Palette {   PALETTE_BLACK = 0 , PALETTE_BLUE = 1 , PALETTE_GREEN = 2 , PALETTE_CYAN = 3 ,   PALETTE_RED = 4 , PALETTE_MAGENTA = 5 , PALETTE_YELLOW = 6 , PALETTE_WHITE = 7 }
enum	LCD_Command { COMMAND_SET_X_WINDOW = 0x2A , COMMAND_SET_Y_WINDOW = 0x2B , COMMAND_PREPARE_FOR_DRAW_DATA = 0x2C , COMMAND_READ_DRAW_DATA = 0x2E }

Functions
	LCD_SetPixelFromPaletteU (x, y,(uint8_t) color)

Variables
volatile uint16_t *const	lcd_data_port = (volatile uint16_t *)0xB4000000
void(*	LCD_ClearScreen )()
uint16_t(*	LCD_GetPixel )(unsigned int x, unsigned int y)
void(*	LCD_GetSize )(unsigned int *width, unsigned int *height)
uint16_t *(*	_FP_LCD_GetVRAMAddress )() __asm__(UCONCAT("LCD_GetVRAMAddress"))
void(*	LCD_Refresh )()
void(*	LCD_SetPixel )(unsigned int x, unsigned int y, uint16_t color)
void(*	LCD_SetPixelFromPaletteU )(unsigned int x, unsigned int y, uint8_t index) __asm__(UCONCAT("LCD_SetPixelFromPalette"))
static unsigned int	y
static unsigned int enum LCD_Palette	color
static unsigned int enum LCD_Palette color void(*	LCD_VRAMBackup )()
void(*	LCD_VRAMRestore )()
void(*	LCD_SendCommandU )(uint16_t command) __asm__(UCONCAT("LCD_SendCommand"))
void(*	LCD_SetDrawingBounds )(unsigned int xstart, unsigned int xend, unsigned int ystart, unsigned int yend)

Detailed Description

Functions for interacting with the LCD and VRAM.

Different levels of indirection are availiable to write to VRAM (direct memory access, getter/setters and palette-based drawing). The contents of VRAM are not automatically drawn to the LCD, and must be rendered with LCD_Refresh.

Example: drawing a 30x50 rectangle at 10, 20 in purple

uint16_t *vram = LCD_GetVRAMAddress();
int width, height;
LCD_GetSize(&width, &height);
 
for (int y = 0; y < 50; ++y) {
    for (int x = 0; x < 30; ++x) {
        vram[(x + 10) + (y + 20) * width] = RGB_TO_RGB565(0x1F, 0x3B, 0x08);
    }
}
 
// Put our changes on the display
LCD_Refresh();

Macro Definition Documentation

RGB565_TO_B

#define RGB565_TO_B

(

rgb565

)

(rgb565 & 0x1F)

Extracts the blue component from an RGB565 value.

Parameters

rgb565

The RGB565 value.

Returns

The blue component.

RGB565_TO_G

#define RGB565_TO_G

(

rgb565

)

((rgb565 >> 5) & 0x3F)

Extracts the green component from an RGB565 value.

Parameters

rgb565

The RGB565 value.

Returns

The green component.

RGB565_TO_R

#define RGB565_TO_R

(

rgb565

)

((rgb565 >> 11) & 0x1F)

Extracts the red component from an RGB565 value.

Parameters

rgb565

The RGB565 value.

Returns

The red component.

RGB_TO_RGB565

#define RGB_TO_RGB565	(		r,
			g,
			b
	)

Value:

    ( \
    ((r & 0x1F) << 11) | \
    ((g & 0x3F) << 5) | \
    (b & 0x1F) \
)

Converts three RGB values into one RGB565 value.

Parameters

r	The red component, between 0 and 31 (0x1F) inclusive.
g	The green component, between 0 and 63 (0x3F) inclusive.
b	The blue component, between 0 and 31 (0x1F) inclusive.

Returns

The specified color, in RGB565 format.

Enumeration Type Documentation

LCD_Command

enum LCD_Command

Passed to LCD_SendCommand.

LCD_Palette

enum LCD_Palette

Passed to LCD_SetPixelFromPalette.

Variable Documentation

LCD_ClearScreen

void(* LCD_ClearScreen) () ( )

extern

Clears the LCD. Fills VRAM with white, but does not refresh the LCD.

LCD_GetPixel

uint16_t(* LCD_GetPixel) (unsigned int x, unsigned int y) ( unsigned int  x, unsigned int  y  )

extern

Returns the color of a pixel. This is not necessarily the color which is being displayed on the LCD, but instead is the color specified for the pixel in the VRAM buffer. Color is in RGB565 format.

Parameters

x,y	The coordinates of the pixel.

Returns

The color of the pixel, in RGB565 format.

LCD_GetSize

void(* LCD_GetSize) (unsigned int *width, unsigned int *height) ( unsigned int *  width, unsigned int *  height  )

extern

Retrieves the size, in pixels, of the LCD.

Parameters

[out]

width,height

The LCD's size.

LCD_Refresh

void(* LCD_Refresh) () ( )

extern

Pushes the content of the VRAM to the LCD.

LCD_SetDrawingBounds

void(* LCD_SetDrawingBounds) (unsigned int xstart, unsigned int xend, unsigned int ystart, unsigned int yend) ( unsigned int  xstart, unsigned int  xend, unsigned int  ystart, unsigned int  yend  )

extern

Sets the region of the next display update. Needs to be called every time. Usefull for partial updates and/or DMA.

You probably want to use this in conjunction with LCD_SendCommand

LCD_SetPixel

void(* LCD_SetPixel) (unsigned int x, unsigned int y, uint16_t color) ( unsigned int  x, unsigned int  y, uint16_t  color  )

extern

Sets the color of a pixel. The result of this operation will not be visible until LCD_Refresh is called. Color is in RGB565 format.

Parameters

x,y	The coordinate of the pixel.
color	The color to set the pixel, in RGB565 format.

LCD_VRAMBackup

unsigned int enum LCD_Palette color void(* LCD_VRAMBackup) ()

(

)

Backs up the current contents of VRAM.

Should be used to prevent display corruption when writing directly to VRAM.

Used in conjunction with LCD_VRAMRestore.

LCD_VRAMRestore

void(* LCD_VRAMRestore) () ( )

extern

Restores the backed up contents of VRAM. The restored content is not displayed until LCD_Refresh is called.

Used in conjunction with LCD_VRAMBackup.