Library to control a Graphics TFT connected to 4-wire SPI - revised for the Raio RA8875 Display Controller.

Dependents:   FRDM_RA8875_mPaint RA8875_Demo RA8875_KeyPadDemo SignalGenerator ... more

Fork of SPI_TFT by Peter Drescher

See Components - RA8875 Based Display

Enhanced touch-screen support - where it previous supported both the Resistive Touch and Capacitive Touch based on the FT5206 Touch Controller, now it also has support for the GSL1680 Touch Controller.

Offline Help Manual (Windows chm)

/media/uploads/WiredHome/ra8875.zip.bin (download, rename to .zip and unzip)

RA8875.h

Committer:
WiredHome
Date:
2014-01-12
Revision:
19:3f82c1161fd2
Child:
20:6e2e4a8372eb

File content as of revision 19:3f82c1161fd2:

#ifndef RA8875_H
#define RA8875_H
#include <mbed.h>

#include "GraphicsDisplay.h"

#define RA8875_DEFAULT_SPI_FREQ 1000000

// Define this to enable code that monitors the performance of various
// graphics commands.
//#define PERF_METRICS

// What better place for some test code than in here...
#define TESTENABLE

#define RGB(r,g,b) ( ((r<<8)&0xF800) | ((g<<3)&0x07E0) | (b>>3) )

/// DOS colors - slightly color enhanced
#define Black RGB(0,0,0)
#define Blue RGB(0,0,187)
#define Green RGB(0,187,0)
#define Cyan RGB(0,187,187)
#define Red RGB(187,0,0)
#define Magenta RGB(187,0,187)
#define Brown RGB(187,187,0)
#define Gray RGB(187,187,187)
#define Charcoal RGB(85,85,85)
#define BrightBlue RGB(85,85,255)
#define BrightGreen RGB(85,255,85)
#define BrightCyan RGB(85,255,255)
#define Orange RGB(255,85,85)
#define Pink RGB(255,85,255)
#define Yellow RGB(255,255,85)
#define White RGB(255,255,255)

//namespace SW_graphics
//{

/// color type definition to let the compiler help keep us honest.
/// 
/// colors can be defined with the RGB(r,g,b) macro, and there
/// are a number of predefined colors:
/// - Black,    Blue,       Green,       Cyan,
/// - Red,      Magenta,    Brown,       Gray,
/// - Charcoal, BrightBlue, BrightGreen, BrightCyan,
/// - Orange,   Pink,       Yellow,      White
///
typedef uint16_t color_t;   

/// background fill info for drawing Text, Rectangles, RoundedRectanges, Circles, Ellipses and Triangles.
typedef enum
{
    NOFILL,     ///< do not fill the object with the background color
    FILL        ///< fill the object space with the background color
} fill_t;

/// return values from functions
//typedef enum
//{
//    noerror,
//    bad_parameter
//} RetCode_t;

class RA8875 : public GraphicsDisplay
{
public:   
    /// font type selection.
    typedef enum
    {
        ISO8859_1,
        ISO8859_2,
        ISO8859_3,
        ISO8859_4
    } font_t;
    
    /// font rotation selection
    typedef enum
    {
        normal,
        rotated
    } font_angle_t;
    
    /// alignment  
    typedef enum
    {
        align_none,
        align_full
    } alignment_t;    
    
    /// Scale factor - 1, 2, 3 4
    typedef unsigned int HorizontalScale;
    
    /// Scale factor - 1, 2, 3, 4
    typedef unsigned int VerticalScale;

    /// Clear screen region
    typedef enum
    {
        FULLWINDOW,
        ACTIVEWINDOW
    } Region_t;
    
    /// Constructor for a display based on the RAiO RA8875 
    /// display controller.
    ///
    /// @param mosi is the SPI master out slave in pin on the mbed.
    /// @param miso is the SPI master in slave out pin on the mbed.
    /// @param sclk is the SPI shift clock pin on the mbed.
    /// @param csel is the DigitalOut pin on the mbed to use as the
    ///         active low chip select for the display controller.
    /// @param reset is the DigitalOut pin on the mbed to use as the 
    ///         active low reset input on the display controller - 
    ///         but this is not currently used.
    /// @param name is a text name for this object, which will permit
    ///         capturing stdout and printf() directly to it.
    ///
    RA8875(PinName mosi, PinName miso, PinName sclk, PinName csel, PinName reset, const char * name = "lcd");
    
    /// Destructor doesn't have much to do.
    //~RA8875();
    
    /// Write a command to the display
    ///
    /// This is a high level command, and may invoke several primitives.
    ///
    /// @param command is the command to write.
    /// @data is optional data to be written to the command register
    ///     and only occurs if the data is in the range [0 - 0xFF].
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t WriteCommand(unsigned char command, unsigned int data = 0xFFFF);
    
    /// Write a data byte to the display
    ///
    /// This is a high level command, and may invoke several primitives.
    ///
    /// @param data is the data to write.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t WriteData(unsigned char data);
    
    /// Read a command register
    ///
    /// @param command is the command register to read.
    /// @returns the value read from the register.
    ///
    unsigned char ReadCommand(unsigned char command);
    
    /// Read a data byte to the display
    ///
    /// This is a high level command, and may invoke several primitives.
    ///
    /// @returns data that was read.
    ///
    unsigned char ReadData(void);
    
    /// Read the display status
    ///
    /// This is a high level command, and may invoke several primitives.
    ///
    /// @returns data that was read.
    ///
    unsigned char ReadStatus(void);

    /// get the width in pixels of the currently active font
    ///
    /// @returns font width in pixels.
    ///    
    unsigned int fontwidth(void);
    
    /// get the height in pixels of the currently active font
    ///
    /// @returns font height in pixels.
    ///    
    unsigned int fontheight(void);
    
    /// get the number of colums based on the currently active font
    ///
    /// @returns number of columns.
    ///    
    virtual int columns(void);

    /// get the number of rows based on the currently active font
    ///
    /// @returns number of rows.
    ///    
    virtual int rows(void);

    /// get the screen width in pixels
    ///
    /// @returns screen width in pixels.
    ///
    virtual int width(void);

    /// get the screen height in pixels
    ///
    /// @returns screen height in pixels.
    ///
    virtual int height(void);

    /// Set cursor position based on the current font size.
    /// 
    /// @param x is the horizontal position in character positions
    /// @param y is the vertical position in character positions
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t locate(unsigned int x, unsigned int y);

    /// Prepare the controller to write text to the screen by positioning
    /// the cursor.
    ///
    /// @param x is the horizontal position in pixels (from the left edge)
    /// @param y is the vertical position in pixels (from the top edge)
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetTextCursor(unsigned int x, unsigned int y);
    
    /// Select the ISO 8859-X font to use next.
    ///
    /// Supported fonts: ISO 8859-1, -2, -3, -4
    ///
    /// @param font selects the font for the subsequent text rendering.
    ///
    /// @note if either hScale or vScale is outside of its permitted range,
    ///     the command is not executed.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetTextFont(font_t font = ISO8859_1);
    
    /// Control the font behavior.
    ///
    /// This command lets you make several modifications to any text that
    /// is written.
    ///
    /// Options can be combined:
    /// Default:
    /// @li Full alignment disabled, 
    /// @li Font with Background color, 
    /// @li Font in normal orientiation,
    /// @li Horizontal scale x 1
    /// @li Vertical scale x 1
    /// @li alignment
    /// 
    /// @param fillit defaults to FILL, but can be NOFILL
    /// @param angle defaults to normal, but can be rotated
    /// @param hScale defaults to 1, but can be 1, 2, 3, or 4,
    ///     and scales the font size by this amount.
    /// @param vScale defaults to 1, but can be 1, 2, 3, or 4,
    ///     and scales the font size by this amount.
    /// @param alignment defaults to align_none, but can be
    ///     align_full.
    /// 
    /// @note if either hScale or vScale is outside of its permitted range,
    ///     the command is not executed.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetTextFontControl(fill_t fillit = FILL, 
        font_angle_t angle = normal, 
        HorizontalScale hScale = 1, 
        VerticalScale vScale = 1, 
        alignment_t alignment = align_none);
    
    /// Control the font size
    ///
    /// This command lets you set the font enlargement for both horizontal
    /// and vertical, independent of the rotation, background, and 
    /// alignment. @see SetTextFontControl.
    ///
    /// @param hScale defaults to 1, but can be 1, 2, 3, or 4,
    ///     and scales the font size by this amount.
    /// @param vScale defaults to 1, but can be 1, 2, 3, or 4,
    ///     and scales the font size by this amount.
    ///
    /// @note if either hScale or vScale is outside of its permitted range,
    ///     the command is not executed.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetTextFontSize(HorizontalScale hScale = 1, VerticalScale vScale = 1);
    
    /// put a character on the screen.
    ///
    /// @param c is the character.
    /// @returns the character, or EOF if there is an error.
    ///
    virtual int _putc(int c);

    /// Write string of text to the display
    ///
    /// @param string is the null terminated string to send to the display.
    ///
    void puts(const char * string);
    
    /// Write string of text to the display at the specified location.
    ///
    /// @param x is the horizontal position in pixels (from the left edge)
    /// @param y is the vertical position in pixels (from the top edge)
    /// @param string is the null terminated string to send to the display.
    ///
    void puts(unsigned int x, unsigned int y, const char * string);
    
    /// Prepare the controller to write binary data to the screen by positioning
    /// the memory cursor.
    ///
    /// @param x is the horizontal position in pixels (from the left edge)
    /// @param y is the vertical position in pixels (from the top edge)
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetMemoryCursor(unsigned int x, unsigned int y);
    
    /// Set the window, which controls where items are written to the screen.
    ///
    /// When something hits the window width, it wraps back to the left side
    /// and down a row. If the initial write is outside the window, it will
    /// be captured into the window when it crosses a boundary.
    ///
    /// @param x is the left edge in pixels.
    /// @param y is the top edge in pixels.
    /// @param width is the window width in pixels.
    /// @param height is the window height in pixels.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t SetWindow(unsigned int x, unsigned int y, unsigned int width, unsigned int height);
    
    /// Clear the screen.
    ///
    /// The behavior is to clear the whole screen. @see clsw().
    ///
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t cls(void);
    
    /// Clear the screen, or clear only the active window.
    ///
    /// The default behavior is to clear the whole screen. With the optional 
    /// parameter, the action can be restricted to the active window, which
    /// can be set with the @see SetWindow method.
    ///
    /// @param region is an optional parameter that defaults to FULLWINDOW
    ///         or may be set to ACTIVEWINDOW.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t clsw(RA8875::Region_t region = FULLWINDOW);

    /// Set the background color.
    ///
    /// @param color is expressed in 16-bit format.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t background(color_t color);
    
    /// Set the background color.
    ///
    /// @param r is the red element of the color.
    /// @param g is the green element of the color.
    /// @param b is the blue element of the color.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t background(unsigned char r, unsigned char g, unsigned char b);
    
    /// Set the foreground color.
    ///
    /// @param color is expressed in 16-bit format.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t foreground(color_t color);
    
    /// Set the foreground color.
    ///
    /// @param R is the red element of the color.
    /// @param G is the green element of the color.
    /// @param B is the blue element of the color.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t foreground(unsigned char R, unsigned char G, unsigned char B);
    
    /// Get the current foreground color value.
    ///
    /// @returns the current foreground color.
    ///
    unsigned int GetForeColor(void);
        
    /// Draw a pixel in the specified color.
    ///
    /// @note As a side effect, this also sets the foreground color 
    ///     affecting all subsequent operations.
    ///
    /// @param x is the horizontal offset to this pixel.
    /// @param y is the vertical offset to this pixel.
    /// @param color defines the color for the pixel.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t pixel(unsigned int x, unsigned int y, color_t color);
    
    /// Draw a pixel in the current foreground color.
    ///
    /// @param x is the horizontal offset to this pixel.
    /// @param y is the veritical offset to this pixel.
    /// @returns success/failure code. @see RetCode_t.
    ///
    virtual RetCode_t pixel(unsigned int x, unsigned int y);
    
    /// Draw a line in the specified color
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param color defines the foreground color.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t line(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        color_t color);

    /// Draw a line
    ///
    /// Draws a line using the foreground color setting.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t line(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2);

    /// Draw a rectangle in the specified color
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param color defines the foreground color.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t rect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        color_t color, fill_t fillit = NOFILL);

    /// Draw a filled rectangle in the specified color
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param color defines the foreground color.
    /// @param fillit is optional to NOFILL the rectangle. default is FILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t fillrect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        color_t color, fill_t fillit = FILL);

    /// Draw a rectangle
    ///
    /// Draws a rectangle using the foreground color setting.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t rect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        fill_t fillit = NOFILL);

    /// Draw a filled rectangle with rounded corners using the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param radius1 defines the horizontal width of the curved corner.
    /// @param radius2 defines the vertical width of the curved corner.
    /// @param color defines the foreground color.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t fillroundrect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int radius1, unsigned int radius2, color_t color, fill_t fillit = FILL);

    /// Draw a rectangle with rounded corners using the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param radius1 defines the horizontal width of the curved corner.
    /// @param radius2 defines the vertical width of the curved corner.
    /// @param color defines the foreground color.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t roundrect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int radius1, unsigned int radius2, color_t color, fill_t fillit = NOFILL);

    /// Draw a rectangle with rounded corners.
    ///
    /// Draws a rectangle with rounded corners using the foreground color setting.
    ///
    /// @param x1 is the horizontal start of the line.
    /// @param y1 is the vertical start of the line.
    /// @param x2 is the horizontal end of the line.
    /// @param y2 is the vertical end of the line.
    /// @param radius1 defines the horizontal width of the curved corner.
    /// @param radius2 defines the vertical width of the curved corner.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t roundrect(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int radius1, unsigned int radius2, fill_t fillit = NOFILL);

    /// Draw a triangle in the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal for point 1.
    /// @param y1 is the vertical for point 1.
    /// @param x2 is the horizontal for point 2.
    /// @param y2 is the vertical for point 2.
    /// @param x3 is the horizontal for point 3.
    /// @param y3 is the vertical for point 3.
    /// @param color defines the foreground color.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t triangle(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int x3, unsigned int y3, color_t color, fill_t fillit = NOFILL);
    
    /// Draw a filled triangle in the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x1 is the horizontal for point 1.
    /// @param y1 is the vertical for point 1.
    /// @param x2 is the horizontal for point 2.
    /// @param y2 is the vertical for point 2.
    /// @param x3 is the horizontal for point 3.
    /// @param y3 is the vertical for point 3.
    /// @param color defines the foreground color.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t filltriangle(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int x3, unsigned int y3, color_t color, fill_t fillit = FILL);

    /// Draw a triangle
    ///
    /// Draws a triangle using the foreground color setting.
    ///
    /// @param x1 is the horizontal for point 1.
    /// @param y1 is the vertical for point 1.
    /// @param x2 is the horizontal for point 2.
    /// @param y2 is the vertical for point 2.
    /// @param x3 is the horizontal for point 3.
    /// @param y3 is the vertical for point 3.
    /// @param fillit is optional to FILL the rectangle. default is NOFILL.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t triangle(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, 
        unsigned int x3, unsigned int y3, fill_t fillit = NOFILL);
    
    /// Draw a circle using the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x is the horizontal center of the circle.
    /// @param y is the vertical center of the circle.
    /// @param radius defines the size of the circle.
    /// @param color defines the foreground color.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t circle(unsigned int x, unsigned int y, unsigned int radius, color_t color, fill_t fillit = NOFILL);

    /// Draw a filled circle using the specified color.
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x is the horizontal center of the circle.
    /// @param y is the vertical center of the circle.
    /// @param radius defines the size of the circle.
    /// @param color defines the foreground color.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t fillcircle(unsigned int x, unsigned int y, unsigned int radius, color_t color, fill_t fillit = FILL);

    /// Draw a circle.
    ///
    /// Draws a circle using the foreground color setting.
    ///
    /// @param x is the horizontal center of the circle.
    /// @param y is the vertical center of the circle.
    /// @param radius defines the size of the circle.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t circle(unsigned int x, unsigned int y, unsigned int radius, fill_t fillit = NOFILL);

    /// Draw an Ellipse using the specified color
    ///
    /// @note As a side effect, this changes the current
    ///     foreground color for subsequent operations.
    ///
    /// @param x is the horizontal center of the ellipse.
    /// @param y is the vertical center of the ellipse.
    /// @param radius1 defines the horizontal width of the ellipse.
    /// @param radius2 defines the vertical width of the ellipse.
    /// @param color defines the foreground color.
    /// @param fillit defines whether the circle is filled or not.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t ellipse(unsigned int x, unsigned int y, unsigned int radius1, unsigned int radius1, 
        color_t color, fill_t fillit = NOFILL);

    /// Draw an Ellipse
    ///
    /// Draws it using the foreground color setting.
    ///
    /// @param x is the horizontal center of the ellipse.
    /// @param y is the vertical center of the ellipse.
    /// @param radius1 defines the horizontal width of the ellipse.
    /// @param radius2 defines the vertical width of the ellipse.
    /// @param fillit defines whether the circle is filled or not.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t ellipse(unsigned int x, unsigned int y, unsigned int radius1, unsigned int radius1, fill_t fillit = NOFILL);
    
    /// Control display power
    ///
    /// @param on when set to true will turn on the display, when false it is turned off.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t Power(bool on);

    /// Reset the display controller via the Software Reset interface.
    ///
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t Reset(void);
    
    /// Set backlight brightness.
    ///
    /// When the built-in PWM is used to control the backlight, this 
    /// API can be used to set the brightness.
    /// 
    /// @param brightness ranges from 0 (off) to 255 (full on)
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t Backlight_u8(unsigned char brightness);
    
    /// Set backlight brightness.
    ///
    /// When the built-in PWM is used to control the backlight, this 
    /// API can be used to set the brightness.
    /// 
    /// @param brightness ranges from 0.0 (off) to 1.0 (full on)
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t Backlight(float brightness);

    /// Set a reference to a bitmap font, provided by the user.
    ///
    /// @note Tool to create the fonts is accessible from its creator
    ///     available at http://www.mikroe.com. 
    ///     Change the data to an array of type char[].
    ///
    /// @param font is a pointer to a specially formed font array.
    ///     This special font array has a 4-byte header, followed by 
    ///     the data:
    ///   - the number of bytes per char
    ///   - the vertical size in pixels for each character
    ///   - the horizontal size in pixels for each character
    ///   - the number of bytes per vertical line (width of the array)
    /// @returns error code.
    ///
    RetCode_t set_font(const unsigned char * font);

    /// Get the RGB value for a DOS color.
    ///
    /// @param i is the color, in the range 0 to 15;
    /// @returns the RGB color of the selected index, or 0 
    ///     if the index is out of bounds.
    ///
    color_t DOSColor(int i);

    /// Get the color name (string) for a DOS color.
    ///
    /// @param i is the color, in the range 0 to 15;
    /// @returns a pointer to a string with the color name,
    ///     or NULL if the index is out of bounds.
    /// 
    const char * DOSColorNames(int i);


#ifdef PERF_METRICS
    /// Clear the performance metrics to zero.
    void ClearPerformance();
    
    /// Report the performance metrics for drawing functions using
    /// printf()
    void ReportPerformance();
#endif

private:
    /// Set the SPI port frequency (in Hz).
    ///
    /// @note attempts to call this API at runtime, with the display
    ///         already online, cause the system to lockup. 
    ///         Not sure why, so moving this to private to run once.
    ///
    /// This uses the mbed SPI driver, and is therefore dependent on
    /// its capabilities. Limited tests were performed for the display
    /// in the range of 1,000,000 to 50,000,000 Hz. The display was
    /// a bit erratic above 20,000,000 Hz, so this became the default,
    /// even though it might have been the bench-level wiring that posed
    /// the limit.
    ///
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t frequency(unsigned long Hz = RA8875_DEFAULT_SPI_FREQ);
    

    /// Initialize the chip, which is normally done as part of the
    /// constructor, so not called by the user.
    ///
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t init(void);
    
    /// Select the peripheral to use it.
    ///
    /// @param chipsel when true will select the peripheral, and when false
    ///     will deselect the chip. This is the logical selection, and
    ///     the pin selection is the invert of this.
    /// @returns success/failure code. @see RetCode_t.
    ///
    RetCode_t select(bool chipsel);

    /// The most primitive - to write a data value to the SPI interface.
    ///
    /// @param data is the value to write.
    /// @returns a value read from the port, since SPI is often shift
    ///     in while shifting out.
    ///
    unsigned char spiwrite(unsigned char data);
    
    /// The most primitive - to read a data value to the SPI interface.
    ///
    /// This is really just a specialcase of the write command, where
    /// the value zero is written in order to read.
    ///
    /// @returns a value read from the port, since SPI is often shift
    ///     in while shifting out.
    ///
    unsigned char spiread();
    
    SPI spi;                        ///< spi port
    DigitalOut cs;                  ///< chip select pin, assumed active low
    DigitalOut res;                 ///< reset pin, assumed active low
    const unsigned char * font;     ///< reference to an external font somewhere in memory
    
    #ifdef PERF_METRICS
    typedef enum
    {
        PRF_CLS,
        PRF_DRAWPOINT,
        PRF_DRAWLINE,
        PRF_DRAWRECTANGLE,
        PRF_DRAWROUNDEDRECTANGLE,
        PRF_DRAWTRIANGLE,
        PRF_DRAWCIRCLE,
        PRF_DRAWELLIPSE,
        METRICCOUNT
    } method_e;
    unsigned long metrics[METRICCOUNT];
    void RegisterPerformance(method_e method);
    Timer performance;
    #endif
};

//}     // namespace

//using namespace SW_graphics;

#endif