twali/src/twali_screen.cpp

/*
#include <TFT_eSPI>


struct twali_screen {
    int x; 
    int y; 
    int w; 
    int h;
    TFT_eSPI * tft;
};

void twali_screen_clip(struct twali_screen * s, int32_t * x, int32_t * y) {
    int cx = *x + s->x;
    int cy = *y + s->y;
    if cx > (    
    
}

void twali_screen_draw_pixel(struct twali_screen * s, int32_t x, int32_t y, uint32_t color) {
    s->tft->drawPixel(x, y, color);
}

void twali_screen_draw_char(struct twali_screen * s, int32_t x, int32_t y, uint16_t c, uint32_t color, uint32_t bg, uint8_t size) {
    s->tft->drawChar(x, y, c, color, bg, size);
}

void twali_screen_draw_line(struct twali_screen * s, int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color) {
    s->tft->drawLine(x, y, x+w, y+h, c, color, bg, size);
}

            drawChar(int32_t x, int32_t y, uint16_t c, uint32_t color, uint32_t bg, uint8_t size),
            drawLine(int32_t xs, int32_t ys, int32_t xe, int32_t ye, uint32_t color),
            drawFastVLine(int32_t x, int32_t y, int32_t h, uint32_t color),
            drawFastHLine(int32_t x, int32_t y, int32_t w, uint32_t color),
            fillRect(int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color);

    virtual int16_t  drawChar(uint16_t uniCode, int32_t x, int32_t y, uint8_t font),
            drawChar(uint16_t uniCode, int32_t x, int32_t y),
            height(void),
            width(void);

    void     setRotation(uint8_t r); // Set the display image orientation to 0, 1, 2 or 3
    uint8_t  getRotation(void);      // Read the current rotation

    void     invertDisplay(bool i);  // Tell TFT to invert all displayed colours


    // The TFT_eSprite class inherits the following functions (not all are useful to Sprite class
    void     setAddrWindow(int32_t xs, int32_t ys, int32_t w, int32_t h), // Note: start coordinates + width and height
             setWindow(int32_t xs, int32_t ys, int32_t xe, int32_t ye);   // Note: start + end coordinates

    // Push (aka write pixel) colours to the TFT (use setAddrWindow() first)
    void     pushColor(uint16_t color),
             pushColor(uint16_t color, uint32_t len),  // Deprecated, use pushBlock()
             pushColors(uint16_t  *data, uint32_t len, bool swap = true), // With byte swap option
             pushColors(uint8_t  *data, uint32_t len); // Deprecated, use pushPixels()

    // Write a solid block of a single colour
    void     pushBlock(uint16_t color, uint32_t len);

    // Write a set of pixels stored in memory, use setSwapBytes(true/false) function to correct endianess
    void     pushPixels(const void *data_in, uint32_t len);

    // Read the colour of a pixel at x,y and return value in 565 format
    uint16_t readPixel(int32_t x, int32_t y);

    // Support for half duplex (bi-directional SDA) SPI bus where MOSI must be switched to input
#ifdef TFT_SDA_READ
#if defined (TFT_eSPI_ENABLE_8_BIT_READ)
    uint8_t  tft_Read_8(void);     // Read 8 bit value from TFT command register
#endif
    void     begin_SDA_Read(void); // Begin a read on a half duplex (bi-directional SDA) SPI bus - sets MOSI to input
    void     end_SDA_Read(void);   // Restore MOSI to output
#endif

    // Graphics drawing
    void     fillScreen(uint32_t color),
             drawRect(int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color),
             drawRoundRect(int32_t x, int32_t y, int32_t w, int32_t h, int32_t radius, uint32_t color),
             fillRoundRect(int32_t x, int32_t y, int32_t w, int32_t h, int32_t radius, uint32_t color);


    void     drawCircle(int32_t x, int32_t y, int32_t r, uint32_t color),
             drawCircleHelper(int32_t x, int32_t y, int32_t r, uint8_t cornername, uint32_t color),
             fillCircle(int32_t x, int32_t y, int32_t r, uint32_t color),
             fillCircleHelper(int32_t x, int32_t y, int32_t r, uint8_t cornername, int32_t delta, uint32_t color),

             drawEllipse(int16_t x, int16_t y, int32_t rx, int32_t ry, uint16_t color),
             fillEllipse(int16_t x, int16_t y, int32_t rx, int32_t ry, uint16_t color),

             //                 Corner 1               Corner 2               Corner 3
             drawTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, uint32_t color),
             fillTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, uint32_t color);

    // Image rendering
    // Swap the byte order for pushImage() and pushPixels() - corrects endianness
    void     setSwapBytes(bool swap);
    bool     getSwapBytes(void);

    // Draw bitmap
    void     drawBitmap( int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t fgcolor),
             drawBitmap( int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t fgcolor, uint16_t bgcolor),
             drawXBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t fgcolor),
             drawXBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t fgcolor, uint16_t bgcolor),
             setBitmapColor(uint16_t fgcolor, uint16_t bgcolor); // Define the 2 colours for 1bpp sprites

    // Set TFT pivot point (use when rendering rotated sprites)
    void     setPivot(int16_t x, int16_t y);
    int16_t  getPivotX(void), // Get pivot x
             getPivotY(void); // Get pivot y

    // The next functions can be used as a pair to copy screen blocks (or horizontal/vertical lines) to another location
    // Read a block of pixels to a data buffer, buffer is 16 bit and the size must be at least w * h
    void     readRect(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t *data);
    // Write a block of pixels to the screen which have been read by readRect()
    void     pushRect(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t *data);

    // These are used to render images or sprites stored in RAM arrays (used by Sprite class for 16bpp Sprites)
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t *data);
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t *data, uint16_t transparent);

    // These are used to render images stored in FLASH (PROGMEM)
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, const uint16_t *data, uint16_t transparent);
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, const uint16_t *data);

    // These are used by Sprite class pushSprite() member function for 1, 4 and 8 bits per pixel (bpp) colours
    // They are not intended to be used with user sketches (but could be)
    // Set bpp8 true for 8bpp sprites, false otherwise. The cmap pointer must be specified for 4bpp
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, uint8_t  *data, bool bpp8 = true, uint16_t *cmap = nullptr);
    void     pushImage(int32_t x, int32_t y, int32_t w, int32_t h, uint8_t  *data, uint8_t  transparent, bool bpp8 = true, uint16_t *cmap = nullptr);

    // This next function has been used successfully to dump the TFT screen to a PC for documentation purposes
    // It reads a screen area and returns the 3 RGB 8 bit colour values of each pixel in the buffer
    // Set w and h to 1 to read 1 pixel's colour. The data buffer must be at least w * h * 3 bytes
    void     readRectRGB(int32_t x, int32_t y, int32_t w, int32_t h, uint8_t *data);

    // Text rendering - value returned is the pixel width of the rendered text
    int16_t  drawNumber(long intNumber, int32_t x, int32_t y, uint8_t font), // Draw integer using specified font number
             drawNumber(long intNumber, int32_t x, int32_t y),               // Draw integer using current font

             // Decimal is the number of decimal places to render
             // Use with setTextDatum() to position values on TFT, and setTextPadding() to blank old displayed values
             drawFloat(float floatNumber, uint8_t decimal, int32_t x, int32_t y, uint8_t font), // Draw float using specified font number
             drawFloat(float floatNumber, uint8_t decimal, int32_t x, int32_t y),               // Draw float using current font

             // Handle char arrays
             // Use with setTextDatum() to position string on TFT, and setTextPadding() to blank old displayed strings
             drawString(const char *string, int32_t x, int32_t y, uint8_t font),  // Draw string using specifed font number
             drawString(const char *string, int32_t x, int32_t y),                // Draw string using current font
             drawString(const String &string, int32_t x, int32_t y, uint8_t font),// Draw string using specifed font number
             drawString(const String &string, int32_t x, int32_t y),              // Draw string using current font

             drawCentreString(const char *string, int32_t x, int32_t y, uint8_t font),  // Deprecated, use setTextDatum() and drawString()
             drawRightString(const char *string, int32_t x, int32_t y, uint8_t font),   // Deprecated, use setTextDatum() and drawString()
             drawCentreString(const String &string, int32_t x, int32_t y, uint8_t font),// Deprecated, use setTextDatum() and drawString()
             drawRightString(const String &string, int32_t x, int32_t y, uint8_t font); // Deprecated, use setTextDatum() and drawString()

    // Text rendering and font handling support funtions
    void     setCursor(int16_t x, int16_t y),                 // Set cursor for tft.print()
             setCursor(int16_t x, int16_t y, uint8_t font);   // Set cursor and font number for tft.print()

    int16_t  getCursorX(void),                                // Read current cursor x position (moves with tft.print())
             getCursorY(void);                                // Read current cursor y position

    void     setTextColor(uint16_t color),                    // Set character (glyph) color only (background not over-written)
             setTextColor(uint16_t fgcolor, uint16_t bgcolor),// Set character (glyph) foreground and backgorund colour
             setTextSize(uint8_t size);                       // Set character size multiplier (this increases pixel size)

    void     setTextWrap(bool wrapX, bool wrapY = false);     // Turn on/off wrapping of text in TFT width and/or height

    void     setTextDatum(uint8_t datum);                     // Set text datum position (default is top left), see Section 6 above
    uint8_t  getTextDatum(void);

    void     setTextPadding(uint16_t x_width);                // Set text padding (background blanking/over-write) width in pixels
    uint16_t getTextPadding(void);                            // Get text padding

#ifdef LOAD_GFXFF
    void     setFreeFont(const GFXfont *f = NULL),            // Select the GFX Free Font
             setTextFont(uint8_t font);                       // Set the font number to use in future
#else
    void     setFreeFont(uint8_t font),                       // Not used, historical fix to prevent an error
             setTextFont(uint8_t font);                       // Set the font number to use in future
#endif

    int16_t  textWidth(const char *string, uint8_t font),     // Returns pixel width of string in specified font
             textWidth(const char *string),                   // Returns pixel width of string in current font
             textWidth(const String &string, uint8_t font),   // As above for String types
             textWidth(const String &string),
             fontHeight(int16_t font),                        // Returns pixel height of string in specified font
             fontHeight(void);                                // Returns pixel width of string in current font

    // Used by library and Smooth font class to extract Unicode point codes from a UTF8 encoded string
    uint16_t decodeUTF8(uint8_t *buf, uint16_t *index, uint16_t remaining),
             decodeUTF8(uint8_t c);

    // Support function to UTF8 decode and draw characters piped through print stream
    size_t   write(uint8_t);

    // Used by Smooth font class to fetch a pixel colour for the anti-aliasing
    void     setCallback(getColorCallback getCol);

    uint16_t fontsLoaded(void); // Each bit in returned value represents a font type that is loaded - used for debug/error handling only

    // Low level read/write
    void     spiwrite(uint8_t);        // legacy support only

    void     writecommand(uint8_t c),  // Send a command, function resets DC/RS high ready for data
             writedata(uint8_t d);     // Send data with DC/RS set high

    void     commandList(const uint8_t *addr); // Send a initialisation sequence to TFT stored in FLASH

    uint8_t  readcommand8( uint8_t cmd_function, uint8_t index = 0); // read 8 bits from TFT
    uint16_t readcommand16(uint8_t cmd_function, uint8_t index = 0); // read 16 bits from TFT
    uint32_t readcommand32(uint8_t cmd_function, uint8_t index = 0); // read 32 bits from TFT


    // Colour conversion
    // Convert 8 bit red, green and blue to 16 bits
    uint16_t color565(uint8_t red, uint8_t green, uint8_t blue);

    // Convert 8 bit colour to 16 bits
    uint16_t color8to16(uint8_t color332);
    // Convert 16 bit colour to 8 bits
    uint8_t  color16to8(uint16_t color565);

    // Convert 16 bit colour to/from 24 bit, R+G+B concatenated into LS 24 bits
    uint32_t color16to24(uint16_t color565);
    uint32_t color24to16(uint32_t color888);

    // Alpha blend 2 colours, see generic "alphaBlend_Test" example
    // alpha =   0 = 100% background colour
    // alpha = 255 = 100% foreground colour
    uint16_t alphaBlend(uint8_t alpha, uint16_t fgc, uint16_t bgc);
    // 16 bit colour alphaBlend with alpha dither (dither reduces colour banding)
    uint16_t alphaBlend(uint8_t alpha, uint16_t fgc, uint16_t bgc, uint8_t dither);
    // 24 bit colour alphaBlend with optional alpha dither
    uint32_t alphaBlend24(uint8_t alpha, uint32_t fgc, uint32_t bgc, uint8_t dither = 0);


    // DMA support functions - these are currently just for SPI writes whe using the STM32 processors
    // Bear in mind DMA will only be of benefit in particular circumstances and can be tricky
    // to manage by noobs. The functions have however been designed to be noob friendly and
    // avoid a few DMA behaviour "gotchas".
    //
    // At best you will get a 2x TFT rendering performance improvement when using DMA because
    // this library handles the SPI bus so efficiently during normal (non DMA) transfers. The best
    // performance improvement scenario is the DMA transfer time is exactly the same as the time it
    // takes for the processor to prepare the next image buffer and initiate another DMA transfer.
    //
    // DMA transfer to the TFT is done while the processor moves on to handle other tasks. Bear
    // this in mind and watch out for "gotchas" like the image buffer going out of scope as the
    // processor leaves a function or its content being changed while the DMA engine is reading it.
    //
    // The compiler MAY change the implied scope of a buffer which has been set aside by creating
    // and an array. For example a buffer defined before a "for-next" loop may get de-allocated when
    // the loop ends. To avoid this use, for example, malloc() and free() to take control of when
    // the buffer space is available and ensure it is not released until DMA is complete.
    //
    // Clearly you should not modify a buffer that is being DMA'ed to the TFT until the DMA is over.
    // Use the dmaBusy() function to check this.  Use tft.startWrite() before invoking DMA so the
    // TFT chip select stays low. If you use tft.endWrite() before DMA is complete then the endWrite
    // function will wait for the DMA to complete, so this may defeat any DMA performance benefit.
    //

    bool     initDMA(void);     // Initialise the DMA engine and attach to SPI bus - typically used in setup()
    void     deInitDMA(void);   // De-initialise the DMA engine and detach from SPI bus - typically not used

    // Push an image to the TFT using DMA, buffer is optional and grabs (double buffers) a copy of the image
    // Use the buffer if the image data will get over-written or destroyed while DMA is in progress
    // If swapping colour bytes is defined, and the double buffer option is NOT used then the bytes
    // in the original data image will be swapped by the function before DMA is initiated.
    // The function will wait for the last DMA to complete if it is called while a previous DMA is still
    // in progress, this simplifies the sketch and helps avoid "gotchas".
    void     pushImageDMA(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t *data, uint16_t *buffer = nullptr);

    // Push a block of pixels into a window set up using setAddrWindow()
    void     pushPixelsDMA(uint16_t *image, uint32_t len);

    // Check if the DMA is complete - use while(tft.dmaBusy); for a blocking wait
    bool     dmaBusy(void); // returns true if DMA is still in progress
    void     dmaWait(void); // wait until DMA is complete

    bool     DMA_Enabled = false;   // Flag for DMA enabled state
    uint8_t  spiBusyCheck = 0;      // Number of ESP32 transfer buffers to check

    // Bare metal functions
    void     startWrite(void);                         // Begin SPI transaction
    void     writeColor(uint16_t color, uint32_t len); // Deprecated, use pushBlock()
    void     endWrite(void);                           // End SPI transaction

    // Set/get an arbitrary library configuration attribute or option
    //       Use to switch ON/OFF capabilities such as UTF8 decoding - each attribute has a unique ID
    //       id = 0: reserved - may be used in fuuture to reset all attributes to a default state
    //       id = 1: Turn on (a=true) or off (a=false) GLCD cp437 font character error correction
    //       id = 2: Turn on (a=true) or off (a=false) UTF8 decoding
    //       id = 3: Enable or disable use of ESP32 PSRAM (if available)
#define CP437_SWITCH 1
#define UTF8_SWITCH  2
#define PSRAM_ENABLE 3
    void     setAttribute(uint8_t id = 0, uint8_t a = 0); // Set attribute value
    uint8_t  getAttribute(uint8_t id = 0);                // Get attribute value

    // Used for diagnostic sketch to see library setup adopted by compiler, see Section 7 above
    void     getSetup(setup_t &tft_settings); // Sketch provides the instance to populate

    // Global variables
    static   SPIClass &getSPIinstance(void); // Get SPI class handle

    int32_t  cursor_x, cursor_y, padX;       // Text cursor x,y and padding setting
    uint32_t textcolor, textbgcolor;         // Text foreground and background colours

    uint32_t bitmap_fg, bitmap_bg;           // Bitmap foreground (bit=1) and background (bit=0) colours

    uint8_t  textfont,  // Current selected font number
             textsize,  // Current font size multiplier
             textdatum, // Text reference datum
             rotation;  // Display rotation (0-3)

    int16_t  _xpivot;   // TFT x pivot point coordinate for rotated Sprites
    int16_t  _ypivot;   // TFT x pivot point coordinate for rotated Sprites

    uint8_t  decoderState = 0;   // UTF8 decoder state        - not for user access
    uint16_t decoderBuffer;      // Unicode code-point buffer - not for user access

*/