Font engine

This section provides APIs to get string information and draw string with specified font size and font color. More...

Overview

This section provides APIs to get string information and draw string with specified font size and font color.

Terms and Acronyms

Terms	Details
SSC	Supplementary Service Codes. For more information, please refer to Wikipedia.
ISO	International Organization for Standardization. For more information, please refer to Wikipedia.
BDF	Bitmap Distribution Format. For more information, please refer to Wikipedia.

How to use the font engine module

• Step 1: Generate the font data files by using the resgen tool. It's mandatory if adding or modifying BDF files. For resource generator tool usage, please change path to ".\tools\pc_tools\resgen_tool" in windows commands and type in "make ?".
• Step 2: Call the font engine API to show string or get string information. Here is an example to show how to show one string with medium font size and white color.
  • Sample code:

    gdi_font_engine_color_t text_color = {0, 255, 255, 255};// White color.
    
    gdi_font_engine_size_t font_size;
    
    // Please make sure that GDI initialization with the gdi_init() is completed before starting the following process;
    
    // Clear screen.
    gdi_draw_filled_rectangle(0, 0, 128, 128, 0);
    
    // Set font size.
    gdi_font_engine_get_font_size(&font_size);
    if (font_size != GDI_FONT_ENGINE_FONT_MEDIUM) {
        font_size = GDI_FONT_ENGINE_FONT_MEDIUM;
    }
    gdi_font_engine_set_font_size(font_size);
    
    // Set color.
    gdi_font_engine_set_text_color(text_color);
    
    // Print String.
    gdi_font_engine_display_string_info_t string_info = {0};
    gdi_font_engine_string_info_t query = {0};
    query.string = L"Test!";
    query.count = wstrlen(L"Test!");
    gdi_font_engine_get_string_information(&query);
    string_info.x = 0;
    string_info.y = 0;
    string_info.string = L"Test!";
    string_info.length = wstrlen(L"Test!");
    string_info.baseline_height = query.baseline; // Suggest to set -1 if the string information is not inquired.
    gdi_font_engine_display_string(&string_info);
    
    
    // Update screen.
    gdi_lcd_update_screen(0, 0, 128, 128);

Functions
uint8_t	gdi_font_engine_set_font_size (gdi_font_engine_size_t font_size)
	This function sets the current font size. More...
void	gdi_font_engine_get_font_size (gdi_font_engine_size_t *font_size)
	This function gets the current font size. More...
void	gdi_font_engine_set_text_color (gdi_font_engine_color_t color)
	This function sets the text color. More...
gdi_font_engine_color_t	gdi_font_engine_get_text_color (void)
	This function gets the text color. More...
uint32_t	gdi_font_engine_display_string (gdi_font_engine_display_string_info_t *parameter)
	This function displays the specific string. More...
uint32_t	gdi_font_engine_get_string_information (gdi_font_engine_string_info_t *query)
	This function gets the detailed information of the specified string. More...

Modules
	Define
	This section defines the macros for the font engine.
	Struct
	This section defines the structures for the font engine.

Function Documentation

uint32_t gdi_font_engine_display_string

(

gdi_font_engine_display_string_info_t *

parameter

)

This function displays the specific string.

Parameters

[in]

parameter

is the user-defined data to draw the string.

Returns

GDI_FONT_ENGINE_OK, the operation completed successfully.

void gdi_font_engine_get_font_size

(

gdi_font_engine_size_t *

font_size

)

This function gets the current font size.

Parameters

[out]

font_size

is the size of the current font.

Returns

void.

uint32_t gdi_font_engine_get_string_information

(

gdi_font_engine_string_info_t *

query

)

This function gets the detailed information of the specified string.

Parameters

[in,out]

query

is the user-defined query information and query the result provided by the font engine.

Returns

Indicates the number of characters to get the information.

gdi_font_engine_color_t gdi_font_engine_get_text_color

(

void

)

This function gets the text color.

Returns

The text color.

uint8_t gdi_font_engine_set_font_size

(

gdi_font_engine_size_t

font_size

)

This function sets the current font size.

Parameters

[in]

font_size

is the font size to set.

Returns

void.

void gdi_font_engine_set_text_color

(

gdi_font_engine_color_t

color

)

This function sets the text color.

Parameters

[in]

color

is the text color.

Returns

void.