Fix more overflows

clip.cpp

@@ -184,19 +184,21 @@ int clip(long long *x0, long long *y0, long long *x1, long long *y1, long long x
 
 			// XXX truncating division
 
+			long long shift = 1LL << (GLOBAL_DETAIL - 32);
+
 			// Now find the intersection point;
 			// use formulas y = y0 + slope * (x - x0), x = x0 + (1 / slope) * (y - y0)
 			if (outcodeOut & TOP) {	 // point is above the clip rectangle
-				x = *x0 + (*x1 - *x0) * (ymax - *y0) / (*y1 - *y0);
+				x = *x0 + ((*x1 - *x0) / shift) * ((ymax - *y0) / shift) / (*y1 - *y0) * shift * shift;
 				y = ymax;
 			} else if (outcodeOut & BOTTOM) {  // point is below the clip rectangle
-				x = *x0 + (*x1 - *x0) * (ymin - *y0) / (*y1 - *y0);
+				x = *x0 + ((*x1 - *x0) / shift) * ((ymin - *y0) / shift) / (*y1 - *y0) * shift * shift;
 				y = ymin;
 			} else if (outcodeOut & RIGHT) {  // point is to the right of clip rectangle
-				y = *y0 + (*y1 - *y0) * (xmax - *x0) / (*x1 - *x0);
+				y = *y0 + ((*y1 - *y0) / shift) * ((xmax - *x0) / shift) / (*x1 - *x0) * shift * shift;
 				x = xmax;
 			} else if (outcodeOut & LEFT) {	 // point is to the left of clip rectangle
-				y = *y0 + (*y1 - *y0) * (xmin - *x0) / (*x1 - *x0);
+				y = *y0 + ((*y1 - *y0) / shift) * ((xmin - *x0) / shift) / (*x1 - *x0) * shift * shift;
 				x = xmin;
 			}
 

geometry.cpp

@@ -307,11 +307,14 @@ double distance_from_line(long long point_x, long long point_y, long long segA_x
 	// These calculations must be made in integers instead of floating point
 	// to make them consistent between x86 and arm floating point implementations.
 	//
-	// Coordinates may be up to 34 bits, so their product is up to 68 bits,
+	// In a 32-bit world, coordinates may be up to 34 bits, so their product is up to 68 bits,
 	// making their sum up to 69 bits. Downshift before multiplying to keep them in range.
-	double something = ((p2x / 4) * (p2x / 8) + (p2y / 4) * (p2y / 8)) * 32.0;
+	//
+	// If the world is bigger than 32 bits, scale down to 32 bits.
+	long long shift = 1LL << (GLOBAL_DETAIL - 32);
+	double something = ((p2x / 4 / shift) * (p2x / 8 / shift) + (p2y / 4 / shift) * (p2y / 8 / shift)) * 32.0 * shift * shift;
 	// likewise
-	double u = (0 == something) ? 0 : ((point_x - segA_x) / 4 * (p2x / 8) + (point_y - segA_y) / 4 * (p2y / 8)) * 32.0 / (something);
+	double u = (0 == something) ? 0 : ((point_x - segA_x) / 4 / shift * (p2x / 8 / shift) + (point_y - segA_y) / 4 / shift * (p2y / 8 / shift)) * 32.0 * shift * shift / (something);
 
 	if (u >= 1) {
 		u = 1;
@@ -682,13 +685,15 @@ drawvec fix_polygon(const drawvec &geom) {
 			xtotal /= count;
 			ytotal /= count;
 
+            long long shift = 1LL << (GLOBAL_DETAIL - 32);
+
 			// figure out which point is furthest from the centroid
 			long long dist2 = 0;
 			long long furthest = 0;
 			for (size_t a = 0; a + 1 < ring.size(); a++) {
 				// division by 16 because these are z0 coordinates and we need to avoid overflow
-				long long xd = (ring[a].x - xtotal) / 16;
+				long long xd = (ring[a].x - xtotal) / 16 / shift;
-				long long yd = (ring[a].y - ytotal) / 16;
+				long long yd = (ring[a].y - ytotal) / 16 / shift;
 				long long d2 = xd * xd + yd * yd;
 				if (d2 > dist2 || (d2 == dist2 && ring[a] < ring[furthest])) {
 					dist2 = d2;
@@ -703,8 +708,8 @@ drawvec fix_polygon(const drawvec &geom) {
 			long long furthestb = 0;
 			for (size_t a = 0; a + 1 < ring.size(); a++) {
 				// division by 16 because these are z0 coordinates and we need to avoid overflow
-				long long xd = (ring[a].x - ring[furthest].x) / 16;
+				long long xd = (ring[a].x - ring[furthest].x) / 16 / shift;
-				long long yd = (ring[a].y - ring[furthest].y) / 16;
+				long long yd = (ring[a].y - ring[furthest].y) / 16 / shift;
 				long long d2 = xd * xd + yd * yd;
 				if (d2 > dist2b || (d2 == dist2b && ring[a] < ring[furthestb])) {
 					dist2b = d2;

plugin.cpp

@@ -385,8 +385,8 @@ serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::
 		for (size_t i = 0; i < dv.size(); i++) {
 			unsigned sx = 0, sy = 0;
 			if (z != 0) {
-				sx = x << (GLOBAL_DETAIL - z);
+				sx = (long long) x << (GLOBAL_DETAIL - z);
-				sy = y << (GLOBAL_DETAIL - z);
+				sy = (long long) y << (GLOBAL_DETAIL - z);
 			}
 			dv[i].x = std::round(dv[i].x / scale) * scale - sx;
 			dv[i].y = std::round(dv[i].y / scale) * scale - sy;

tile.cpp

@@ -1265,8 +1265,8 @@ void *run_prefilter(void *v) {
 		// Offset from tile coordinates back to world coordinates
 		unsigned sx = 0, sy = 0;
 		if (rpa->z != 0) {
-			sx = rpa->tx << (GLOBAL_DETAIL - rpa->z);
+			sx = (long long) rpa->tx << (GLOBAL_DETAIL - rpa->z);
-			sy = rpa->ty << (GLOBAL_DETAIL - rpa->z);
+			sy = (long long) rpa->ty << (GLOBAL_DETAIL - rpa->z);
 		}
 		for (size_t i = 0; i < tmp_feature.geometry.size(); i++) {
 			tmp_feature.geometry[i].x += sx;