Adafruit_GFX.cpp

/*
See rights and use declaration in License.h
This is a "butchered" version of the official library
The I2C interface code has been removed!  Software SPI only
*/
#include "Adafruit_GFX.h"
#include "glcdfont.c"

#define pgm_read_byte(addr) (*(const unsigned char *)(addr))  // __AVR__  #include <avr/pgmspace.h>

Adafruit_GFX::Adafruit_GFX(int16_t w, int16_t h):
    WIDTH(w), HEIGHT(h)
{
    _width    = WIDTH;
    _height   = HEIGHT;
    rotation  = 0;
    cursor_y  = cursor_x    = 0;
    textsize  = 1;
    textcolor = textbgcolor = 0xFFFF;
    wrap      = true;
}

// Draw a circle outline
void Adafruit_GFX::drawCircle(int16_t x0, int16_t y0, int16_t r, uint16_t color)
{
    int16_t f = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x = 0;
    int16_t y = r;

    drawPixel(x0  , y0 + r, color);
    drawPixel(x0  , y0 - r, color);
    drawPixel(x0 + r, y0  , color);
    drawPixel(x0 - r, y0  , color);

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f += ddF_y;
        }
        x++;
        ddF_x += 2;
        f += ddF_x;

        drawPixel(x0 + x, y0 + y, color);
        drawPixel(x0 - x, y0 + y, color);
        drawPixel(x0 + x, y0 - y, color);
        drawPixel(x0 - x, y0 - y, color);
        drawPixel(x0 + y, y0 + x, color);
        drawPixel(x0 - y, y0 + x, color);
        drawPixel(x0 + y, y0 - x, color);
        drawPixel(x0 - y, y0 - x, color);
    }
}

void Adafruit_GFX::drawCircleHelper( int16_t x0, int16_t y0,
                                     int16_t r, uint8_t cornername, uint16_t color)
{
    int16_t f     = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x     = 0;
    int16_t y     = r;

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f     += ddF_y;
        }
        x++;
        ddF_x += 2;
        f     += ddF_x;
        if (cornername & 0x4)
        {
            drawPixel(x0 + x, y0 + y, color);
            drawPixel(x0 + y, y0 + x, color);
        }
        if (cornername & 0x2)
        {
            drawPixel(x0 + x, y0 - y, color);
            drawPixel(x0 + y, y0 - x, color);
        }
        if (cornername & 0x8)
        {
            drawPixel(x0 - y, y0 + x, color);
            drawPixel(x0 - x, y0 + y, color);
        }
        if (cornername & 0x1)
        {
            drawPixel(x0 - y, y0 - x, color);
            drawPixel(x0 - x, y0 - y, color);
        }
    }
}

void Adafruit_GFX::fillCircle(int16_t x0, int16_t y0, int16_t r, uint16_t color)
{
    drawFastVLine(x0, y0 - r, 2 * r + 1, color);
    fillCircleHelper(x0, y0, r, 3, 0, color);
}

// Used to do circles and roundrects
void Adafruit_GFX::fillCircleHelper(int16_t x0, int16_t y0, int16_t r,
                                    uint8_t cornername, int16_t delta, uint16_t color)
{

    int16_t f     = 1 - r;
    int16_t ddF_x = 1;
    int16_t ddF_y = -2 * r;
    int16_t x     = 0;
    int16_t y     = r;

    while (x < y)
    {
        if (f >= 0)
        {
            y--;
            ddF_y += 2;
            f     += ddF_y;
        }
        x++;
        ddF_x += 2;
        f     += ddF_x;

        if (cornername & 0x1)
        {
            drawFastVLine(x0 + x, y0 - y, 2 * y + 1 + delta, color);
            drawFastVLine(x0 + y, y0 - x, 2 * x + 1 + delta, color);
        }
        if (cornername & 0x2)
        {
            drawFastVLine(x0 - x, y0 - y, 2 * y + 1 + delta, color);
            drawFastVLine(x0 - y, y0 - x, 2 * x + 1 + delta, color);
        }
    }
}

// Bresenham's algorithm - thx wikpedia
void Adafruit_GFX::drawLine(int16_t x0, int16_t y0,
                            int16_t x1, int16_t y1,
                            uint16_t color)
{
    int16_t steep = abs(y1 - y0) > abs(x1 - x0);
    if (steep)
    {
        swap(x0, y0);
        swap(x1, y1);
    }

    if (x0 > x1)
    {
        swap(x0, x1);
        swap(y0, y1);
    }

    int16_t dx, dy;
    dx = x1 - x0;
    dy = abs(y1 - y0);

    int16_t err = dx / 2;
    int16_t ystep;

    if (y0 < y1)
    {
        ystep = 1;
    }
    else
    {
        ystep = -1;
    }

    for (; x0 <= x1; x0++)
    {
        if (steep)
        {
            drawPixel(y0, x0, color);
        }
        else
        {
            drawPixel(x0, y0, color);
        }
        err -= dy;
        if (err < 0)
        {
            y0 += ystep;
            err += dx;
        }
    }
}

// Draw a rectangle
void Adafruit_GFX::drawRect(int16_t x, int16_t y,
                            int16_t w, int16_t h,
                            uint16_t color)
{
    drawFastHLine(x, y, w, color);
    drawFastHLine(x, y + h - 1, w, color);
    drawFastVLine(x, y, h, color);
    drawFastVLine(x + w - 1, y, h, color);
}

void Adafruit_GFX::drawFastVLine(int16_t x, int16_t y, int16_t h, uint16_t color)
{
    // Update in subclasses if desired!
    drawLine(x, y, x, y + h - 1, color);
}

void Adafruit_GFX::drawFastHLine(int16_t x, int16_t y, int16_t w, uint16_t color)
{
    // Update in subclasses if desired!
    drawLine(x, y, x + w - 1, y, color);
}

void Adafruit_GFX::fillRect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t color)
{
    // Update in subclasses if desired!
    for (int16_t i = x; i < x + w; i++)
    {
        drawFastVLine(i, y, h, color);
    }
}

void Adafruit_GFX::fillScreen(uint16_t color)
{
    fillRect(0, 0, _width, _height, color);
}

// Draw a rounded rectangle
void Adafruit_GFX::drawRoundRect(int16_t x, int16_t y, int16_t w, int16_t h, int16_t r, uint16_t color)
{
    // smarter version
    drawFastHLine(x + r  , y    , w - 2 * r, color); // Top
    drawFastHLine(x + r  , y + h - 1, w - 2 * r, color); // Bottom
    drawFastVLine(x    , y + r  , h - 2 * r, color); // Left
    drawFastVLine(x + w - 1, y + r  , h - 2 * r, color); // Right
    // draw four corners
    drawCircleHelper(x + r    , y + r    , r, 1, color);
    drawCircleHelper(x + w - r - 1, y + r    , r, 2, color);
    drawCircleHelper(x + w - r - 1, y + h - r - 1, r, 4, color);
    drawCircleHelper(x + r    , y + h - r - 1, r, 8, color);
}

// Fill a rounded rectangle
void Adafruit_GFX::fillRoundRect(int16_t x, int16_t y, int16_t w, int16_t h, int16_t r, uint16_t color)
{
    // smarter version
    fillRect(x + r, y, w - 2 * r, h, color);

    // draw four corners
    fillCircleHelper(x + w - r - 1, y + r, r, 1, h - 2 * r - 1, color);
    fillCircleHelper(x + r    , y + r, r, 2, h - 2 * r - 1, color);
}

// Draw a triangle
void Adafruit_GFX::drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint16_t color)
{
    drawLine(x0, y0, x1, y1, color);
    drawLine(x1, y1, x2, y2, color);
    drawLine(x2, y2, x0, y0, color);
}

// Fill a triangle
void Adafruit_GFX::fillTriangle ( int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint16_t color)
{
    int16_t a, b, y, last;

    // Sort coordinates by Y order (y2 >= y1 >= y0)
    if (y0 > y1)
    {
        swap(y0, y1);
        swap(x0, x1);
    }
    if (y1 > y2)
    {
        swap(y2, y1);
        swap(x2, x1);
    }
    if (y0 > y1)
    {
        swap(y0, y1);
        swap(x0, x1);
    }

    if(y0 == y2)   // Handle awkward all-on-same-line case as its own thing
    {
        a = b = x0;
        if(x1 < a)      a = x1;
        else if(x1 > b) b = x1;
        if(x2 < a)      a = x2;
        else if(x2 > b) b = x2;
        drawFastHLine(a, y0, b - a + 1, color);
        return;
    }

    int16_t
    dx01 = x1 - x0,
    dy01 = y1 - y0,
    dx02 = x2 - x0,
    dy02 = y2 - y0,
    dx12 = x2 - x1,
    dy12 = y2 - y1;
    int32_t
    sa   = 0,
    sb   = 0;

    // For upper part of triangle, find scanline crossings for segments
    // 0-1 and 0-2.  If y1=y2 (flat-bottomed triangle), the scanline y1
    // is included here (and second loop will be skipped, avoiding a /0
    // error there), otherwise scanline y1 is skipped here and handled
    // in the second loop...which also avoids a /0 error here if y0=y1
    // (flat-topped triangle).
    if(y1 == y2) last = y1;   // Include y1 scanline
    else         last = y1 - 1; // Skip it

    for(y = y0; y <= last; y++)
    {
        a   = x0 + sa / dy01;
        b   = x0 + sb / dy02;
        sa += dx01;
        sb += dx02;
        /* longhand:
        a = x0 + (x1 - x0) * (y - y0) / (y1 - y0);
        b = x0 + (x2 - x0) * (y - y0) / (y2 - y0);
        */
        if(a > b) swap(a, b);
        drawFastHLine(a, y, b - a + 1, color);
    }

    // For lower part of triangle, find scanline crossings for segments
    // 0-2 and 1-2.  This loop is skipped if y1=y2.
    sa = dx12 * (y - y1);
    sb = dx02 * (y - y0);
    for(; y <= y2; y++)
    {
        a   = x1 + sa / dy12;
        b   = x0 + sb / dy02;
        sa += dx12;
        sb += dx02;
        /* longhand:
        a = x1 + (x2 - x1) * (y - y1) / (y2 - y1);
        b = x0 + (x2 - x0) * (y - y0) / (y2 - y0);
        */
        if(a > b) swap(a, b);
        drawFastHLine(a, y, b - a + 1, color);
    }
}

void Adafruit_GFX::drawBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t color)
{

    int16_t i, j, byteWidth = (w + 7) / 8;

    for(j = 0; j < h; j++)
    {
        for(i = 0; i < w; i++ )
        {
            if(pgm_read_byte(bitmap + j * byteWidth + i / 8) & (128 >> (i & 7)))
            {
                drawPixel(x + i, y + j, color);
            }
        }
    }
}

// Draw a 1-bit color bitmap at the specified x, y position from the
// provided bitmap buffer (must be PROGMEM memory) using color as the
// foreground color and bg as the background color.
void Adafruit_GFX::drawBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t color, uint16_t bg)
{
    int16_t i, j, byteWidth = (w + 7) / 8;

    for(j = 0; j < h; j++)
    {
        for(i = 0; i < w; i++ )
        {
            if(pgm_read_byte(bitmap + j * byteWidth + i / 8) & (128 >> (i & 7)))
            {
                drawPixel(x + i, y + j, color);
            }
            else
            {
                drawPixel(x + i, y + j, bg);
            }
        }
    }
}

//Draw XBitMap Files (*.xbm), exported from GIMP,
//Usage: Export from GIMP to *.xbm, rename *.xbm to *.c and open in editor.
//C Array can be directly used with this function
void Adafruit_GFX::drawXBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t color)
{
    int16_t i, j, byteWidth = (w + 7) / 8;

    for(j = 0; j < h; j++)
    {
        for(i = 0; i < w; i++ )
        {
            if(pgm_read_byte(bitmap + j * byteWidth + i / 8) & (1 << (i % 8)))
            {
                drawPixel(x + i, y + j, color);
            }
        }
    }
}


size_t Adafruit_GFX::write(uint8_t c) // void Adafruit_GFX::write(uint8_t c)
{
    if (c == '\n')
    {
        cursor_y += textsize * 8;
        cursor_x  = 0;
    }
    else if (c == '\r')
    {
        // skip em
    }
    else
    {
        drawChar(cursor_x, cursor_y, c, textcolor, textbgcolor, textsize);
        cursor_x += textsize * 6;
        if (wrap && (cursor_x > (_width - textsize * 6)))
        {
            cursor_y += textsize * 8;
            cursor_x = 0;
        }
    }
    return 1;
}

// Draw a character
void Adafruit_GFX::drawChar(int16_t x, int16_t y, unsigned char c, uint16_t color, uint16_t bg, uint8_t size)
{
    if((x >= _width)            || // Clip right
            (y >= _height)           || // Clip bottom
            ((x + 6 * size - 1) < 0) || // Clip left
            ((y + 8 * size - 1) < 0))   // Clip top
        return;

    for (int8_t i = 0; i < 6; i++ )
    {
        uint8_t line;
        if (i == 5)
            line = 0x0;
        else
            line = pgm_read_byte(font + (c * 5) + i);
        for (int8_t j = 0; j < 8; j++)
        {
            if (line & 0x1)
            {
                if (size == 1) // default size
                    drawPixel(x + i, y + j, color);
                else    // big size
                {
                    fillRect(x + (i * size), y + (j * size), size, size, color);
                }
            }
            else if (bg != color)
            {
                if (size == 1) // default size
                    drawPixel(x + i, y + j, bg);
                else    // big size
                {
                    fillRect(x + i * size, y + j * size, size, size, bg);
                }
            }
            line >>= 1;
        }
    }
}

void Adafruit_GFX::setCursor(int16_t x, int16_t y)
{
    cursor_x = x;
    cursor_y = y;
}

void Adafruit_GFX::setTextSize(uint8_t s)
{
    textsize = (s > 0) ? s : 1;
}

void Adafruit_GFX::setTextColor(uint16_t c)
{
    // For 'transparent' background, we'll set the bg
    // to the same as fg instead of using a flag
    textcolor = textbgcolor = c;
}

void Adafruit_GFX::setTextColor(uint16_t c, uint16_t b)
{
    textcolor   = c;
    textbgcolor = b;
}

void Adafruit_GFX::setTextWrap(boolean w)
{
    wrap = w;
}

uint8_t Adafruit_GFX::getRotation(void) const
{
    return rotation;
}

void Adafruit_GFX::setRotation(uint8_t x)
{
    rotation = (x & 3);
    switch(rotation)
    {
    case 0:
    case 2:
        _width  = WIDTH;
        _height = HEIGHT;
        break;
    case 1:
    case 3:
        _width  = HEIGHT;
        _height = WIDTH;
        break;
    }
}

// Return the size of the display (per current rotation)
int16_t Adafruit_GFX::width(void) const
{
    return _width;
}

int16_t Adafruit_GFX::height(void) const
{
    return _height;
}

void Adafruit_GFX::invertDisplay(boolean i)
{
    // Do nothing, must be subclassed if supported
}