src/includes/kernel/util.c

@@ -42,4 +42,32 @@ void setColor(volatile unsigned char* fb, colour_t pixel, long x, long y, long p
 
 
 
+// Takes a computed sin value and finds what pixel it cooresponds to
+int scale_to_y_pixel(double y) 
+{
+    return (int) ((SCREEN_HEIGHT / 2) * (1 - y));
+}
+
+// Takes a horizontal pixel location and finds where it would be in a normal graph 0 < t < 2pi
+double scale_to_x_origin(int x)
+{
+    return x * 2 * M_PI / SCREEN_WIDTH;
+}
+
+
+// Returns the coordinates of the sin function. sin[x] = y coordinate on the horizontal pixel x.
+int *getCoordinates()
+{
+    int x = 0;
+    int *yCords = (int*) malloc(sizeof(int) * SCREEN_WIDTH);
+    memset(yCords, 0, SCREEN_WIDTH);
+    for (x = 0; x < SCREEN_WIDTH; ++x)
+    {
+        double float_x = scale_to_x_origin(x);
+        yCords[x] = scale_to_y_pixel(sin(float_x));
+    }
+
+    return yCords;
+}
+
 

src/includes/kernel/util.h

@@ -12,6 +12,9 @@ arm-016-util.h
 
 #define COLOUR_DELTA    0.05    /* Float from 0 to 1 incremented by this amount */
 
+#include <math.h>
+#include <stdlib.h>
+
 typedef struct {
     float r;
     float g;
@@ -22,4 +25,8 @@ typedef struct {
 
 extern void setColor(volatile unsigned char* fb, colour_t pixel, long x, long y, long pitch);
 
-#endif
+extern int * getCoordinates();
+extern double scale_to_x_origin(int);
+extern int scale_to_y_pixel(double);
+
+#endif