Diff: main.cpp

Revision:

0:a954bd7fd162

Child:

1:a9641f372bea

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Apr 13 19:27:43 2013 +0000
@@ -0,0 +1,106 @@
+/* Mandelbrot for mbed - April 2013
+ * Uses Peter Drescher's library for Mikroelektronika's TFT-Proto screen, an inexpensive SPI-driven QVGA touch panel
+ * Library: http://mbed.org/cookbook/SPI-driven-QVGA-TFT
+ * Manufacturer's page for the screen: http://www.mikroe.com/add-on-boards/display/tft-proto/
+ * UK distributor: http://www.mcustore.com/tft-proto-board.html
+ * Partly adapted from Kamil Ondrousek's code for another screen: http://mbed.org/users/JLS/code/Mandelbrot-2/
+ */
+#include "mbed.h"
+#include "SPI_TFT.h"
+#include "Arial12x12.h"
+#include "touch_tft.h"
+
+#define WIDTH 320
+#define HEIGHT 240
+
+touch_tft tt(p18,p19,p16,p17,p11, p12, p13, p14, p15,"TFT"); // x+,x-,y+,y-,mosi, miso, sclk, cs, reset
+
+void drawMandelbrot(float centrex, float centrey, float zoom, int maxIter) {
+    float xmin = centrex - 1.0/zoom;
+    float xmax = centrex + 1.0/zoom;
+    float ymin = centrey - HEIGHT / (WIDTH * zoom);
+    float ymax = centrey + HEIGHT / (WIDTH *zoom);
+
+    float dx = (xmax - xmin) / WIDTH;
+    float dy = (ymax - ymin) / HEIGHT;
+
+    float y = ymin;
+
+    float c;
+    unsigned int cr, cg, cb;
+    
+    for (int j = 0; j < HEIGHT; j++) {
+        float x = xmin;
+
+        for (int i = 0;  i < WIDTH; i++) {
+            float a = x;
+            float b = y;
+            int n = 0;
+
+            while (n < maxIter) {
+                float aa = a * a;
+                float bb = b * b;
+                float twoab = 2.0 * a * b;
+
+                a = aa - bb + x;
+                b = twoab + y;
+
+                if(aa + bb > 16.0) {
+                    break;
+                }
+                n++;
+            }
+
+            if (n == maxIter) {
+                //It's in the set - Black
+                tt.pixel(i,j,Black);
+            } else {
+                //Not in the set - pick a colour
+                c = 3.0 * (maxIter-n)/maxIter;
+                cr = ((c < 1.0) ? 255 * ( 1.0 - c) : (c > 2.0) ? 255 * (c - 2.0) : 0);
+                cg = ((c < 1.0) ? 255 * c : (c > 2.0) ? 0 : 255 * (2.0 - c));
+                cb = ((c < 1.0) ? 0 : (c > 2.0) ? 255 * (3.0 - c) : 255 * (c - 1.0));
+                tt.pixel(i,j, RGB(cr,cg,cb));
+            }
+            x += dx;
+        }
+        y += dy;
+    }
+}
+
+int main()
+{
+    //Setup screen
+    tt.claim(stdout);        // send stdout to the TFT display
+    tt.background(Black);    // set background to black
+    tt.foreground(White);    // set chars to white
+    tt.cls();                // clear the screen
+    tt.set_font((unsigned char*) Arial12x12);  // select the font
+    tt.set_orientation(1);
+    tt.calibrate();          // calibrate the touch
+    point p;
+
+    tt.locate(0,0);
+
+    //Setup base Mandelbrot
+    float centrex = -0.5;
+    float centrey = 0.0;
+    float zoom=0.5;
+    int maxiterations = 150;
+
+    while(true) {
+        //Draw it    
+        drawMandelbrot(centrex, centrey, zoom, maxiterations);
+    
+        //Wait for a touch
+        p=tt.get_touch();
+        while(!tt.is_touched(p)) {
+            p=tt.get_touch();
+        }
+        //Set new centre and zoom
+        p = tt.to_pixel(p);
+        centrex += (2.0 * p.x - WIDTH) / (zoom * WIDTH);
+        centrey += (2.0 * p.y - HEIGHT) / (zoom * HEIGHT);
+        zoom *= 4.0;
+    }
+}
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