Diff: Graphics/Graphics.cpp

Revision:

0:2a5dccfd318f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Graphics/Graphics.cpp	Thu Jan 14 00:49:39 2010 +0000
@@ -0,0 +1,117 @@
+/* 
+ * libmbed-graphics 2D and wireframe 3D graphics library for the MBED
+ * microcontroller platform
+ * Copyright (C) <2009> Michael Sheldon <mike@mikeasoft.com>
+ * Optimized and adapted for AbstractLCD interface
+ * Copyright (C) <2010> Igor Skochinsky <skochinsky@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "Graphics.h"
+
+// swap two values
+#define SWAP(a, b) (((a) == (b)) || (((a) ^= (b)), ((b) ^= (a)), ((a) ^= (b))))
+
+Graphics::Graphics(AbstractLCD *lcd)
+    : _lcd(lcd) { 
+    _cx3d = _lcd->width() / 2;
+    _cy3d = _lcd->height() / 2;
+    _cz3d = 150;
+}
+
+void Graphics::line(int x0, int y0, int x1, int y1, int colour) {
+    // Bresenham
+    //printf("line(%d, %d, %d, %d, %d)\n", x0, y0, x1, y1, colour);
+    bool steep = abs(y1 - y0) > abs(x1 - x0);
+    int temp, deltax, deltay, error, ystep, y, x;
+    if (steep) {
+        temp = y0;
+        y0 = x0;
+        x0 = temp;
+        temp = y1;
+        y1 = x1;
+        x1 = temp;
+    }
+    if (x0 > x1) {
+        temp = x1;
+        x1 = x0;
+        x0 = temp;
+        temp = y1;
+        y1 = y0;
+        y0 = temp;
+    }
+    deltax = x1 - x0;
+    deltay = abs(y1 - y0);
+    error = deltax / 2;
+    y = y0;
+    if (y0 < y1) {
+        ystep = 1;
+    } else {
+        ystep = -1;
+    }
+    for (x=x0; x<=x1; x++) {
+        if (steep) {
+            _lcd->pixel(y, x, colour);
+        } else {
+            _lcd->pixel(x, y, colour);
+        }
+        error = error - deltay;
+        if (error < 0) {
+            y = y + ystep;
+            error = error + deltax;
+        }
+    }
+}
+
+void Graphics::line3d(int x0, int y0, int z0, int x1, int y1, int z1, int colour) {
+    if (z0 + _cz3d <= 0 || z1 + _cz3d <= 0) {
+        // Behind the camera
+        return;
+    }
+    
+    int u0 = _cx3d + x0 * _cz3d / (z0 + _cz3d);
+    int v0 = _cy3d + y0 * _cz3d / (z0 + _cz3d);
+    int u1 = _cx3d + x1 * _cz3d / (z1 + _cz3d);
+    int v1 = _cy3d + y1 * _cz3d / (z1 + _cz3d);
+    line(u0, v0, u1, v1, colour);
+}
+
+void Graphics::circle(int cx, int cy, int radius, int colour) {
+    int x = 0;
+    int y = radius;
+    int d = 3 - (2 * radius);
+
+    while (x <= y) {
+        _lcd->pixel(cx + x, cy + y, colour);
+        _lcd->pixel(cx + y, cy + x, colour);
+        _lcd->pixel(cx - x, cy + y, colour);
+        _lcd->pixel(cx + y, cy - x, colour);
+        _lcd->pixel(cx - x, cy - y, colour);
+        _lcd->pixel(cx - y, cy - x, colour);
+        _lcd->pixel(cx + x, cy - y, colour);
+        _lcd->pixel(cx - y, cy + x, colour);
+
+        if (d<0)
+            d += (4 * x) + 6;
+        else
+        {
+            d += (4 * (x - y)) + 10;
+            y--;
+        }
+        x++;
+    }
+}