touch.h File Reference

#include "glcd_types.h"
#include "types.h"

Go to the source code of this file.

Classes
struct	TP_Coordinate
struct	TP_ButtonArea

Functions
void	TP_Init (bool skip_calibration)
	Initializes the touch panel.
bool	TP_IsInitialized (void)
bool	TP_IsCalibrated (void)
void	TP_Calibrate (void)
	Blocks until calibration is completed successfully.
const TP_Coordinate *	TP_WaitForTouch (void)
	Blocks until a touch event is detected.
const LCD_Coordinate *	TP_GetLCDCoordinateFor (const TP_Coordinate *const tp_point)
	Converts the touch panel coordinates to LCD coordinates.
TP_ButtonArea	TP_AssignButtonArea (LCD_Button button, LCD_Coordinate pos)
	Assigns a button area to the given button.
void	TP_WaitForButtonPress (TP_ButtonArea button)
	Blocks until the given button area is pressed.
bool	TP_HasButtonBeenPressed (TP_ButtonArea button, const TP_Coordinate *const touch_point)
	Checks if the given button area has been pressed during the touch event which occurred at the given touch point.

Function Documentation

TP_AssignButtonArea()

TP_ButtonArea TP_AssignButtonArea	(	LCD_Button	button,
		LCD_Coordinate	pos
	)

Assigns a button area to the given button.

Parameters

button	The button to assign the area to.
pos	The position of the button.

Returns

The button area.

Definition at line 436 of file touch.c.

{
    const LCD_Obj obj = {
        .comps_size = 1,
        .comps =
            (LCD_Component[]){
                (LCD_Component){
                    .type = LCD_COMP_BUTTON,
                    .pos = pos,
                    .object.button = &button,
                },
            },
    };
 
    LCD_BBox bbox;
    if (LCD_CalcBBoxForObject(&obj, &bbox) != LCD_ERR_OK)
    {
        return (TP_ButtonArea){0};
    }
 
    return (TP_ButtonArea){
        .pos = pos,
        .width = abs(bbox.bottom_right.x - bbox.top_left.x),
        .height = abs(bbox.bottom_right.y - bbox.top_left.y),
    };
}

TP_Calibrate()

void TP_Calibrate

(

void

)

Blocks until calibration is completed successfully.

Note

This function is automatically called if skip_calibration is false in TP_Init.

Definition at line 399 of file touch.c.

{
    if (!initialized)
        return;
 
    while (!calibrate())
        ;
}

TP_GetLCDCoordinateFor()

const LCD_Coordinate * TP_GetLCDCoordinateFor

(

const TP_Coordinate *const

tp_point

)

Converts the touch panel coordinates to LCD coordinates.

Parameters

tp_point

The touch panel coordinates.

Returns

The LCD coordinates, or NULL if either the touch panel is not initialized or tp_point = NULL.

Definition at line 419 of file touch.c.

{
    if (!initialized || !tp_point)
        return NULL;
 
    static LCD_Coordinate lcd_point;
    TP_CalibrationMatrix matrix = current_calib_matrix;
    if (matrix.divider == 0 || !tp_point)
        return NULL;
 
    lcd_point.x = ((matrix.a_n * tp_point->x) + (matrix.b_n * tp_point->y) + matrix.c_n) / matrix.divider;
    lcd_point.y = ((matrix.d_n * tp_point->x) + (matrix.e_n * tp_point->y) + matrix.f_n) / matrix.divider;
    return &lcd_point;
}

TP_HasButtonBeenPressed()

bool TP_HasButtonBeenPressed	(	TP_ButtonArea	button,
		const TP_Coordinate *const	touch_point
	)

Checks if the given button area has been pressed during the touch event which occurred at the given touch point.

Parameters

button	The button to check.
touch_point	The touch point to check.

Returns

True if the button has been pressed, false otherwise.

Definition at line 475 of file touch.c.

{
    if (!touch_point)
        return false;
 
    // We should map the coordinates to the LCD coordinates, because the buttons pos
    // is in LCD coordinates!
    const LCD_Coordinate *touch_lcd_pos = TP_GetLCDCoordinateFor(touch_point);
    if (!touch_lcd_pos)
        return false;
 
    const bool between_w = IS_BETWEEN_EQ(touch_lcd_pos->x, button.pos.x + 1, button.pos.x + button.width - 1);
    const bool between_h = IS_BETWEEN_EQ(touch_lcd_pos->y, button.pos.y + 1, button.pos.y + button.height - 1);
    return between_w && between_h;
}

TP_Init()

void TP_Init

(

bool

skip_calibration

)

Initializes the touch panel.

Parameters

skip_calibration

If true, calibration is skipped.

Note

If you skip calibration, the TP_WaitForTouch() could return incorrect values.

Definition at line 373 of file touch.c.

{
    LPC_GPIO0->FIODIR |= (1 << 6);  // P0.6 CS is output
    LPC_GPIO2->FIODIR |= (0 << 13); // P2.13 TP_INT is input
    TP_CS(1);
 
    spi_init(); // Initialize SPI interface for touch panel
    initialized = true;
 
    if (skip_calibration)
        return;
 
    TP_Calibrate();
    // assert(calibratated && initialized); // Should never fail.
}

TP_IsCalibrated()

bool TP_IsCalibrated

(

void

)

Definition at line 394 of file touch.c.

{
    return calibratated;
}

TP_IsInitialized()

bool TP_IsInitialized

(

void

)

Definition at line 389 of file touch.c.

{
    return initialized;
}

TP_WaitForButtonPress()

void TP_WaitForButtonPress

(

TP_ButtonArea

button

)

Blocks until the given button area is pressed.

Parameters

button

The button to wait for.

Definition at line 463 of file touch.c.

{
    if (!initialized)
        return;
 
    TP_Coordinate *touch_point;
    do
    {
        touch_point = (TP_Coordinate *)TP_WaitForTouch();
    } while (!TP_HasButtonBeenPressed(button, touch_point));
}

TP_WaitForTouch()

const TP_Coordinate * TP_WaitForTouch

(

void

)

Blocks until a touch event is detected.

Returns

The X, Y coordinates of the touched point, or NULL if the touch panel is not initialized.

Note

If you call this function without first calibrating the panel, the returned value may be incorrect.

Definition at line 408 of file touch.c.

{
    if (!initialized)
        return NULL;
 
    static TP_Coordinate tp_coords;
    while (!poll_touch(&tp_coords))
        ;
    return &tp_coords;
}