Graphical context

Graphical context is an encapsulation of the system graphical context and serves to unify rendering procedures and isolate platform-dependent code.

The interface:

class graphic
{
public:
    graphic(system_context &context);

    void init(const rect &max_size, color background_color);
    void release();

    void set_background_color(color background_color);

    void clear(const rect &position);

    void flush(const rect &updated_size);

    void draw_pixel(const rect &position, color color_);

    void draw_line(const rect &position, color color_, uint32_t width = 1);

    rect measure_text(const std::string &text, const font &font_);
    void draw_text(const rect &position, const std::string &text, color color_, const font &font_);

    void draw_rect(const rect &position, color fill_color);
    void draw_rect(const rect &position, color border_color, color fill_color, uint32_t border_width, uint32_t round);

    /// draw some buffer on context
    void draw_buffer(const rect &position, uint8_t *buffer, int32_t left_shift, int32_t top_shift);

    /// draw another graphic on context
    void draw_graphic(const rect &position, graphic &graphic_, int32_t left_shift, int32_t top_shift);
};

constructor

Takes the system context from the window as input

init

Initialization of the subsystem

• max_size - maximum size of the drawing field
• background_color - fill color

release

Deinitialization of the subsystem, clearing

set_background_color

Change fill color

clear

Clearing the area with fill color

• position - coordinates of the area to be cleared

flush

Resetting (drawing) the area to the system graphic context

• updated_size - coordinates of the reset area

draw_pixel

Drawing a point

• position - coordinates of the point
• color_ - color of the point

draw_line

Drawing a line

• position - coordinates of the start and end points
• color_ - line color
• width - line thickness

measure_text

Returns the dimensions of the text line in pixels

• text - line
• font_ - font

draw_text

Draw text string

• position - coordinates of the upper left corner of the string
• text - line text
• color_ - color
• font_ - font

draw_rect #1

Drawing a simple rectangle

• position - coordinates
• fill_color - fill color

draw_rect #2

Drawing a rectangle with border and rounding

• position - coordinates
• border_color - border color
• fill_color - fill color
• border_width - border thickness
• round - radius of rounding

draw_buffer

Draw buffer with RGB32 color depth

• position - coordinates for drawing
• buffer - buffer
• buffer_size - buffer size in bytes

draw_graphic

Drawing another graphic context

• position - coordinates for drawing
• graphic_ - graphic context
• left_shift - x offset
• top_shift - y offset