FUNCTIONS IN DETAIL

int (*init)(drvthis); 
Driver * drvthis;

The init() function. It starts up the LCD, initializes all variables, allocates private data space and stores the pointer by calling store_private_ptr();

void (*close)(drvthis); 
Driver * drvthis;

Shut down the connection with the LCD. Called just before unloading the driver.

int (*width)(drvthis); 
Driver * drvthis;

Get the screen width in characters. The result is 1-based.

int (*height)(drvthis); 
Driver * drvthis;

Get the screen height in character lines. The result is 1-based.

void (*clear)(drvthis); 
Driver * drvthis;

Clear the framebuffer.

void (*flush)(drvthis); 
Driver * drvthis;

Flush the framebuffer to the LCD.

void (*string)(drvthis,  
 x,  
 y,  
 str); 
Driver * drvthis;
int  x;
int  y;
char * str;

Place string str into position (x,y) in the framebuffer. All coordinates are 1-based, i.e. (1,1) is top left. The driver should check for overflows, i.e. that the positional parameters are within the screen's boundaries and cut off the part of the string that is out of bounds.

void (*chr)(drvthis,  
 x,  
 y,  
 c); 
Driver * drvthis;
int  x;
int  y;
char  c;

Place a single character c into position (x,y) in the framebuffer. The driver should check for overflows, i.e. that the positional parameters are within the screen's boundaries and ignore the request if the character is out of bounds.

void (*vbar)(drvthis,  
 x,  
 y,  
 len,  
 promille,  
 options); 
Driver * drvthis;
int  x;
int  y;
int  len;
int  promille;
int  options;

Draw a vertical bar at position (x,y) that has maximal length len, where a fraction of (promille / 1000) is filled.

void (*hbar)(drvthis,  
 x,  
 y,  
 len,  
 promille,  
 options); 
Driver * drvthis;
int  x;
int  y;
int  len;
int  promille;
int  options;

Draw a horizontal bar at position (x,y) that has maximal length len, where a fraction of (promille / 1000) is filled.

void (*num)(drvthis,  
 x,  
 num); 
Driver * drvthis;
int  x;
int  num;

Display big number num at horizontal position x.

void (*heartbeat)(drvthis,  
 state); 
Driver * drvthis;
int  state;

Sets the heartbeat to the indicated state: 0=off 1=graph1 2=graph2 HEARTBEAT_ON to say that we want to display/refresh the heartbeat. The driver choose how to do it. See MtxOrb.c

void (*icon)(drvthis,  
 x,  
 y,  
 icon); 
Driver * drvthis;
int  x;
int  y;
int  icon;

Draw named icon icon at position (x,y).

void (*cursor)(drvthis,  
 x,  
 y,  
 type); 
Driver * drvthis;
int  x;
int  y;
int  type;

Move cursor to position (x,y), setting its type to type.

void (*set_char)(drvthis,  
 ch,  
 dat); 
Driver * drvthis;
char  ch;
unsigned char * dat;

The set_char function expects a simple block of data with 1 byte for each pixel-line. (So that is 8 bytes for a 5x8 char)

int (*get_free_chars)(drvthis); 
Driver * drvthis;

int (*cellwidth)(drvthis); 
Driver * drvthis;

Return the width of a character cell in pixels. The result is 1-based.

int (*cellheight)(drvthis); 
Driver * drvthis;

Return the height of a character cell in pixels. The result is 1-based.

int (*get_contrast)(drvthis); 
Driver * drvthis;

Get the contrast value from the driver. The return value is an integer in the range from 0 to 1000. Many displays do not support getting or setting contrast using software.

int (*set_contrast)(drvthis,  
 promille); 
Driver * drvthis;
int  promille;

Sets the contrast to the given value, which is an integer in the range from 0 to 1000. It is up to the driver to map the logical interval [0, 1000] into the interval that the hardware supports. Many displays do not support software setting of contrast.

int (*get_brightness)(drvthis,  
 state); 
Driver * drvthis;
int  state;

Get the brightness value from the driver for the given backlight state. The parameter state determnies which one is returned. The return value is an integer in the range from 0 to 1000. Many displays do not support getting or setting brightness using software.

int (*set_brightness)(drvthis,  
 state,  
 promille); 
Driver * drvthis;
int  state;
int  promille;

Set the brightness for the given backlight state to the value given. Value must be an integer in the range from 0 to 1000. It is up to the driver to map the logical interval [0, 1000] into the interval that the hardware supports. Many displays do not support software setting of brightness.

void (*backlight)(drvthis,  
 state); 
Driver * drvthis;
int  state;

Sets the backlight to the given brightness state. Often hardware can only support two values for the backlight: on and off. In that case any value of state > 0 will switch the backlight on.

void (*output)(drvthis,  
 state); 
Driver * drvthis;
int  state;

Sets the output value. Some displays/wirings have a general purpose output, which can be controlled by calling this function. See the 'output' command in the 'widget language'.

const char *(*get_key)(drvthis); 
Driver * drvthis;

Checks if a key has been pressed on the device. Returns NULL for "no key pressed", or a string describing the pressd key. These characters should match the keypad-layout.

const char *(*get_info)(drvthis); 
Driver * drvthis;

Returns a string describing the driver and its features.

char (*config_get_bool)(sectionname,  
 keyname,  
 skip,  
 default_value); 
char * sectionname;
char * keyname;
int  skip;
char  default_value;

Call to server. Retrieve a bool from the config file. Sectionname should be the name of the driver (as in the struct). If the key cannot be found, the default value will be returned. skip should be 0 usually, but if you want to retrieve multiple identical keys, then increase skip to get every next value.

int (*config_get_int)(sectionname,  
 keyname,  
 skip,  
 default_value); 
char * sectionname;
char * keyname;
int  skip;
int  default_value;

Call to server. Retrieve an integer from the config file.

double (*config_get_float)(sectionname,  
 keyname,  
 skip,  
 default_value); 
char * sectionname;
char * keyname;
int  skip;
double  default_value;

Call to server. Retrieve a float from the config file.

char *(*config_get_string)(sectionname,  
 keyname,  
 skip,  
 default); 
char * sectionname;
char * keyname;
int  skip;
char * default;

Call to server. Retrieve a string from the config file. Fill result with a pointer to some available space. You can fill it with a default value. If the key is found, it will be overwritten with the value from the key. Note that you should always first copy the the returned string. It is in the address space of the server, and will be freed at the next call.

int config_has_section(sectionname); 
char * sectionname;

Returns wether a section exists. Does not need to be called prior to a call to a config_get_* function.

int config_has_key(sectionname,  
 keyname); 
char * sectionname;
char * keyname;

Returns the number of times a key exists. Does not need to be called prior to a call to a config_get_* function.

First version, Joris Robijn, 20011016