gfx-lib_blueforcer/Adafruit_GFX.cpp

/***********************************
This is a our graphics core library, for all our displays. 
We'll be adapting all the
existing libaries to use this core to make updating, support 
and upgrading easier!

Adafruit invests time and resources providing this open source code, 
please support Adafruit and open-source hardware by purchasing 
products from Adafruit!

Written by Limor Fried/Ladyada  for Adafruit Industries.  
BSD license, check license.txt for more information
All text above must be included in any redistribution
****************************************/


#include "Adafruit_GFX.h"
#include "glcdfont.c"
#include <avr/pgmspace.h>

// draw a circle outline
void Adafruit_GFX::drawCircle(uint16_t x0, uint16_t y0, uint16_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(uint16_t x0, uint16_t y0,
				       uint16_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(uint16_t x0, uint16_t y0, uint16_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(uint16_t x0, uint16_t y0, uint16_t r,
				    uint8_t cornername, uint16_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(uint16_t x, uint16_t y, 
			    uint16_t w, uint16_t h, 
			    uint16_t color) {
  Serial.println('[]');
  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(uint16_t x, uint16_t y, 
				 uint16_t h, uint16_t color) {
  // stupidest version - update in subclasses if desired!
  for (uint16_t j=y; j<y+h; j++) {
    drawPixel(x, j, color);
  }
}


void Adafruit_GFX::drawFastHLine(uint16_t x, uint16_t y, 
				 uint16_t w, uint16_t color) {
  // stupidest version - update in subclasses if desired!
  for (uint16_t i=x; i<x+w; i++) {
    drawPixel(i, y, color);
  }
}

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

// draw a rounded rectangle!
void Adafruit_GFX::drawRoundRect(uint16_t x, uint16_t y, uint16_t w,
uint16_t h, uint16_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(uint16_t x, uint16_t y, uint16_t w,
				 uint16_t h, uint16_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(uint16_t x0, uint16_t y0,
				uint16_t x1, uint16_t y1, 
				uint16_t x2, uint16_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 ( uint16_t x0, uint16_t y0,
				     uint16_t x1, uint16_t y1, 
				     uint16_t x2, uint16_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,
    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(uint16_t x, uint16_t y, 
			      const uint8_t *bitmap, uint16_t w, uint16_t h,
			      uint16_t color) {
  for (uint16_t j=0; j<h; j++) {
    for (uint16_t i=0; i<w; i++ ) {
      if (pgm_read_byte(bitmap + i + (j/8)*w) & _BV(j%8)) {
	drawPixel(x+i, y+j, color);
      }
    }
  }
}


#if ARDUINO >= 100
size_t Adafruit_GFX::write(uint8_t c) {
#else
void Adafruit_GFX::write(uint8_t c) {
#endif
  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 (cursor_x > (width() - textsize*6)) {
      cursor_y += textsize*8;
      cursor_x = 0;
    }
  }
#if ARDUINO >= 100
  return 1;
#endif
}

// draw a character
void Adafruit_GFX::drawChar(uint16_t x, uint16_t y, char c,
			    uint16_t color, uint16_t bg, uint8_t size) {
  for (uint8_t i=0; i<6; i++ ) {
    uint8_t line;
    if (i == 5) 
      line = 0x0;
    else 
      line = pgm_read_byte(font+(c*5)+i);
    for (uint8_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(uint16_t x, uint16_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) {
  textcolor = c;
  textbgcolor = c; 
  // for 'transparent' background, we'll set the bg 
  // to the same as fg instead of using a flag
}

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