MaxOS::gui::Font Class Reference

A class that can be used to draw text. More...

#include <font.h>

Public Member Functions
	Font (const uint8_t *font_data)
	Construct a new Font object.
virtual void	draw_text (int32_t x, int32_t y, common::Colour foreground_colour, common::Colour background_colour, common::GraphicsContext *context, string text)
	write the entire text to the screen
virtual void	draw_text (int32_t x, int32_t y, common::Colour foreground_colour, common::Colour background_colour, common::GraphicsContext *context, string text, common::Rectangle< int32_t > limit_area)
	write the entire text to the screen
virtual size_t	get_text_height (string)
	Get the height of the text.
virtual size_t	get_text_width (string)
	Get the width of the text.

Public Attributes
bool	is_bold { false }
	Should the font be drawn in bold.
bool	is_italic { false }
	Should the font be drawn in italic.
bool	is_underlined { false }
	Should the font be drawn with an underline.
bool	is_strikethrough { false }
	Should the font be drawn with a strikethrough.

Protected Attributes
bool	m_is_8_by_8 = { true }
	Is the font 8 pixels by 8 pixels per character.
uint8_t	m_font8x8 [2048] = { 0 }
	The 8x8 font data.

Detailed Description

A class that can be used to draw text.

Definition at line 27 of file font.h.

Constructor & Destructor Documentation

Font()

Font::Font ( const uint8_t *  font_data )

explicit

Construct a new Font object.

Parameters

font_data

The 8x8 font data to use

Definition at line 22 of file font.cpp.

                                   {
 
    // Store the font data
    for(int i = 0; i < 2048; ++i) {
        m_font8x8[i] = font_data[i];
    }
}

References m_font8x8.

Member Function Documentation

draw_text() [1/2]

void Font::draw_text ( int32_t  x, int32_t  y, common::Colour  foreground_colour, common::Colour  background_colour, common::GraphicsContext *  context, string  text  )

virtual

write the entire text to the screen

Parameters

x	The x coordinate of the text
y	The y coordinate of the text
foreground_colour	The letter colour
background_colour	The background colour
context	The graphics context to draw the text on
text	The text to draw

Definition at line 41 of file font.cpp.

                                                                  {
 
    // Calculate the rectangle of the text
    int32_t top = 0;
    int32_t left = 0;
    int32_t width = get_text_width(text);
    int32_t height = get_text_height(text);
 
    // Create the rectangle
    Rectangle<int32_t> text_area(left, top, width, height);
 
    // Draw the text
    draw_text(x, y, foreground_colour, background_colour, context, text, text_area);
}

References draw_text(), get_text_height(), and get_text_width().

Referenced by MaxOS::gui::widgets::Button::draw(), MaxOS::gui::widgets::InputBox::draw(), MaxOS::gui::widgets::Text::draw(), draw_text(), and MaxOS::drivers::console::VESABootConsole::put_character().

draw_text() [2/2]

void Font::draw_text ( int32_t  x, int32_t  y, common::Colour  foreground_colour, common::Colour  background_colour, common::GraphicsContext *  context, string  text, common::Rectangle< int32_t >  limit_area  )

virtual

write the entire text to the screen

Parameters

x	The x coordinate of the text
y	The y coordinate of the text
foreground_colour	The letter colour
background_colour	The background colour
context	The graphics context to draw the text on
text	The text to draw
limit_area	The area of the text to draw

Definition at line 70 of file font.cpp.

                                                          {
 
    // Convert the colours
    uint32_t foreground = context->colour_to_int(foreground_colour);
    uint32_t background = context->colour_to_int(background_colour);
 
    // Ensure the area is within the actual area of the text
    if(limit_area.top < 0) {
        limit_area.height += limit_area.top;
        limit_area.top = 0;
    }
 
    if(limit_area.left < 0) {
        limit_area.width += limit_area.left;
        limit_area.left = 0;
    }
 
    // Clamp the height and width max
    if(limit_area.top + limit_area.height > (int) get_text_height(text))
        limit_area.height = get_text_height(text) - limit_area.top;
 
    if(limit_area.left + limit_area.width > (int) get_text_width(text))
        limit_area.width = get_text_width(text) - limit_area.left;
 
    // Calculate limits
    int32_t x_limit = limit_area.left + limit_area.width;
    int32_t y_limit = limit_area.top + limit_area.height;
 
    // Draw the text from top to bottom
    for(int y_bit_map_offset = limit_area.top; y_bit_map_offset < y_limit; y_bit_map_offset++) {
        for(int x_bit_map_offset = limit_area.left; x_bit_map_offset < x_limit; ++x_bit_map_offset) {
 
            // If the y is the middle then add a strikethrough
            if(is_strikethrough && y_bit_map_offset == y_limit / 2) {
 
                // Draw the pixel
                context->put_pixel(x + x_bit_map_offset, y + y_bit_map_offset, foreground);
                continue;
            }
 
            // If the y is the bottom then add an underline
            if(is_underlined && y_bit_map_offset == y_limit - 1) {
 
                // Draw the pixel
                context->put_pixel(x + x_bit_map_offset, y + y_bit_map_offset, foreground);
                continue;
            }
 
            // Get the character
            uint8_t character = text[x_bit_map_offset / 8];
 
            // Check if this pixel  is set or not
            bool set = m_font8x8[(uint16_t) character * 8 + y_bit_map_offset] & (128 >> (x_bit_map_offset % 8));
 
            // Draw the pixel
            context->put_pixel(x + x_bit_map_offset, y + y_bit_map_offset, set ? foreground : background);
 
        }
    }
}

References get_text_height(), get_text_width(), MaxOS::common::Rectangle< Type >::height, is_strikethrough, is_underlined, MaxOS::common::Rectangle< Type >::left, m_font8x8, MaxOS::common::Rectangle< Type >::top, and MaxOS::common::Rectangle< Type >::width.

get_text_height()

size_t Font::get_text_height ( string  text )

virtual

Get the height of the text.

Parameters

text	The text to get the height of

Returns

The height of the text

Definition at line 140 of file font.cpp.

                                        {
 
    return 8;
 
}

Referenced by draw_text(), and draw_text().

get_text_width()

size_t Font::get_text_width ( string  text )

virtual

Get the width of the text.

Parameters

text	The text to get the width of

Returns

The width of the text

Definition at line 152 of file font.cpp.

                                       {
 
    return text.length() * 8;
}

Referenced by draw_text(), and draw_text().

Member Data Documentation

is_bold

bool MaxOS::gui::Font::is_bold { false }

Should the font be drawn in bold.

Definition at line 37 of file font.h.

{ false };                     

is_italic

bool MaxOS::gui::Font::is_italic { false }

Should the font be drawn in italic.

Definition at line 38 of file font.h.

{ false };                   

is_strikethrough

bool MaxOS::gui::Font::is_strikethrough { false }

Should the font be drawn with a strikethrough.

Definition at line 40 of file font.h.

{ false };            

Referenced by draw_text().

is_underlined

bool MaxOS::gui::Font::is_underlined { false }

Should the font be drawn with an underline.

Definition at line 39 of file font.h.

{ false };               

Referenced by draw_text().

m_font8x8

uint8_t MaxOS::gui::Font::m_font8x8[2048] = { 0 }

protected

The 8x8 font data.

Definition at line 30 of file font.h.

{ 0 };              

Referenced by draw_text(), and Font().

m_is_8_by_8

bool MaxOS::gui::Font::m_is_8_by_8 = { true }

protected

Is the font 8 pixels by 8 pixels per character.

Definition at line 29 of file font.h.

{ true };                

---

The documentation for this class was generated from the following files:

• /home/runner/work/MaxOS/MaxOS/kernel/include/gui/font.h
• /home/runner/work/MaxOS/MaxOS/kernel/src/gui/font.cpp