Started implementing in state.cpp. Added State::positionPoint(). It

compiles, but is not tested at all.
Added some methods in state.h (but did not implement them, apparently).

lib/settings.h

@@ -17,7 +17,12 @@ class Settings
 
 	public:
 		Settings( void );
-
+		point getUL( void );
+		point getUR( void );
+		point getBL( void );
+		point getBR( void );
+		int getWhiteTreshold( void );
+		int getBlackTreshold( void );
 
 	private:
 		//upper left, upper right etc...

lib/state.cpp

@@ -1,13 +1,47 @@
 #include "state.h"
+#include <malloc.h>
 
 int State::size = 19;
 
 State::State( void )
 {
-	//does nothing yet
+	board = (type*)malloc(sizeof(type) * size * size);
 }
 
-State generateState (SDL_Surface *board)
+State State::generateState (SDL_Surface *boardImg, Settings settings)
 {
-
+	State state;
+	int i, j, x, y, r, sum;
+	point p;
+	r = 20;
+	for (i = 0; i < size; i++) {
+		for (j = 0; j < size; j++) {
+			p = positionPoint(i, j, settings);
+			for (y = p.y-r; y < p.y+r; y++) {
+				for (x = p.x-r; x < p.x+r; x++) {
+					uint32_t px = PX(boardImg, x, y);
+					sum += PXR(px) + PXG(px) + PXB(px);
+				}
+			}
+			type t = BOARD;
+			if (sum < settings.getBlackTreshold()) t = BLACK;
+			if (sum > settings.getWhiteTreshold()) t = WHITE;
+			PX_(state.board, i, j, size, size) = t;
+		}
+	}
+	return state;
 }
+
+point State::positionPoint(int i, int j, Settings s)
+{
+	point ul = s.getUL(), ur = s.getUR(), bl = s.getBL(), br = s.getBR();
+	point topp, botp, pp;
+	topp.x = ul.x + (i*(ur.x-ul.x))/size;
+	topp.y = ul.y + (i*(ur.y-ul.y))/size;
+	botp.x = bl.x + (i*(br.x-bl.x))/size;
+	botp.y = bl.y + (i*(br.y-bl.y))/size;
+	pp.x = topp.x + (j*(botp.x-topp.x))/size;
+	pp.y = topp.y + (j*(botp.y-topp.y))/size;
+	return pp;
+}
+

lib/state.h

@@ -5,10 +5,18 @@
 #include <SDL/SDL.h>
 #include <stdint.h>
 
+// get pixel/something in array p of size w*h 
 #define PX_(p, x, y, w, h) ((p)[(x)+(y)*(w)])
+// get pixel in SDL_Surface i
 #define PX(i,x,y) (PX_((uint32_t*)(i)->pixels, (x), (y), (i)->w, (i)->h))
+// get color components of pixel value. should probably be done in a nicer way
+#define PXR(px) ((px) & 0xff)
+#define PXG(px) (((px) & 0xff00) >> 8)
+#define PXB(px) (((px) & 0xff0000) >> 16)
+// iterate over SDL_Surface s with variables x, y
 #define iter_pixels(s,x,y) for (x = 0; x < s->w; x++) for (y = 0; y < s->h; y++)
 
+
 /**
  * Describes the current state of a go board.
  */
@@ -28,7 +36,14 @@ class State
 
 
 	private:
+		/*
+		 * Get the image point corresponding to board position (i, j) using
+		 * settings s.
+		 */
+		static point positionPoint(int i, int j, Settings s);
+
 		static int size;
+		type *board; // array describing the board situation
 
 };