A derived version of the BSD licensed Adafrut GFX library for the SSD1306 controller for an OLED 128x32 or 128x64 display using SPI or I2C.

Fork of Adafruit_GFX by Neal Horman

Revision:
0:c3dcd4c4983a
Child:
9:ddb97c9850a2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Adafruit_GFX.cpp	Mon Jul 16 02:19:36 2012 +0000
@@ -0,0 +1,447 @@
+/***********************************
+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
+****************************************/
+
+/*
+ *  Modified by Neal Horman 7/14/2012 for use in LPC1768
+ */
+
+#include "mbed.h"
+
+#include "Adafruit_GFX.h"
+#include "glcdfont.h"
+
+#ifdef WANT_ABSTRACTS
+// 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)
+{
+    // stupidest version - 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)
+{
+    // stupidest version - 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)
+{
+    // stupidest version - 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,
+        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);
+    }
+}
+#endif
+
+void Adafruit_GFX::drawBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t color)
+{
+    for (int16_t j=0; j<h; j++)
+    {
+        for (int16_t i=0; i<w; i++ )
+        {
+            if (bitmap[i + (j/8)*w] & _BV(j%8))
+                drawPixel(x+i, y+j, color);
+        }
+    }
+}
+
+size_t Adafruit_GFX::writeChar(uint8_t c)
+{
+    if (c == '\n')
+    {
+        cursor_y += textsize*8;
+        cursor_x = 0;
+    }
+    else if (c == '\r')
+        cursor_x = 0;
+    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 + 5 * size - 1) < 0) || // Clip left
+        ((y + 8 * size - 1) < 0) // Clip top
+        )
+    return;
+    
+    for (int8_t i=0; i<6; i++ )
+    {
+        uint8_t line = 0;
+
+        if (i == 5) 
+            line = 0x0;
+        else 
+            line = 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);
+#ifdef WANT_ABSTRACTS
+                else // big size
+                    fillRect(x+(i*size), y+(j*size), size, size, color);
+#endif
+            }
+            else if (bg != color)
+            {
+                if (size == 1) // default size
+                    drawPixel(x+i, y+j, bg);
+#ifdef WANT_ABSTRACTS
+                else // big size
+                    fillRect(x+i*size, y+j*size, size, size, bg);
+#endif
+            }
+            line >>= 1;
+        }
+    }
+}
+void Adafruit_GFX::setRotation(uint8_t x)
+{
+    x %= 4;  // cant be higher than 3
+    rotation = x;
+    switch (x)
+    {
+        case 0:
+        case 2:
+            _width = _rawWidth;
+            _height = _rawHeight;
+            break;
+        case 1:
+        case 3:
+            _width = _rawHeight;
+            _height = _rawWidth;
+            break;
+    }
+}