From 686ab56c4ad1ecb48cb0a6fac2d4288f55d910ad Mon Sep 17 00:00:00 2001
From: Erica Fischer <enf@felt.com>
Date: Mon, 18 Mar 2024 12:33:26 -0700
Subject: [PATCH] Bringing back reverted overflow changes, one at a time

---
 clip.cpp   | 10 +++++-----
 main.cpp   |  2 +-
 plugin.cpp |  6 +++---
 tile.cpp   |  6 +++---
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/clip.cpp b/clip.cpp
index 8df69bc7..1157f514 100644
--- a/clip.cpp
+++ b/clip.cpp
@@ -177,7 +177,7 @@ int clip(long long *x0, long long *y0, long long *x1, long long *y1, long long x
 		} else {
 			// failed both tests, so calculate the line segment to clip
 			// from an outside point to an intersection with clip edge
-			long long x = *x0, y = *y0;
+			__int128 x = *x0, y = *y0;
 
 			// At least one endpoint is outside the clip rectangle; pick it.
 			int outcodeOut = outcode0 ? outcode0 : outcode1;
@@ -187,16 +187,16 @@ int clip(long long *x0, long long *y0, long long *x1, long long *y1, long long x
 			// 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 + (__int128) (*x1 - *x0) * (ymax - *y0) / (*y1 - *y0);
 				y = ymax;
 			} else if (outcodeOut & BOTTOM) {  // point is below the clip rectangle
-				x = *x0 + (*x1 - *x0) * (ymin - *y0) / (*y1 - *y0);
+				x = *x0 + (__int128) (*x1 - *x0) * (ymin - *y0) / (*y1 - *y0);
 				y = ymin;
 			} else if (outcodeOut & RIGHT) {  // point is to the right of clip rectangle
-				y = *y0 + (*y1 - *y0) * (xmax - *x0) / (*x1 - *x0);
+				y = *y0 + (__int128) (*y1 - *y0) * (xmax - *x0) / (*x1 - *x0);
 				x = xmax;
 			} else if (outcodeOut & LEFT) {	 // point is to the left of clip rectangle
-				y = *y0 + (*y1 - *y0) * (xmin - *x0) / (*x1 - *x0);
+				y = *y0 + (__int128) (*y1 - *y0) * (xmin - *x0) / (*x1 - *x0);
 				x = xmin;
 			}
 
diff --git a/main.cpp b/main.cpp
index 147ed9c7..bf31232b 100644
--- a/main.cpp
+++ b/main.cpp
@@ -2431,7 +2431,7 @@ std::pair<int, metadata> read_input(std::vector<source> &sources, char *fname, i
 
 		double total_tile_count = 0;
 		for (int i = 1; i <= maxzoom; i++) {
-			double tile_count = ceil(area_sum / ((1LL << (GLOBAL_DETAIL - i)) * (1LL << (GLOBAL_DETAIL - i))));
+			double tile_count = ceil(area_sum / ((__int128) (1LL << (GLOBAL_DETAIL - i)) * (__int128) (1LL << (GLOBAL_DETAIL - i))));
 			total_tile_count += tile_count;
 
 			// 2M tiles is an arbitrary limit, chosen to make tiling jobs
diff --git a/plugin.cpp b/plugin.cpp
index c7ca0e59..d613bd28 100644
--- a/plugin.cpp
+++ b/plugin.cpp
@@ -383,10 +383,10 @@ serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::
 		// Scale and offset geometry from global to tile
 		double scale = 1LL << geometry_scale;
 		for (size_t i = 0; i < dv.size(); i++) {
-			unsigned sx = 0, sy = 0;
+			long long sx = 0, sy = 0;
 			if (z != 0) {
-				sx = x << (GLOBAL_DETAIL - z);
-				sy = y << (GLOBAL_DETAIL - z);
+				sx = (long long) x << (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;
diff --git a/tile.cpp b/tile.cpp
index af829b5b..2a6b6a52 100644
--- a/tile.cpp
+++ b/tile.cpp
@@ -1263,10 +1263,10 @@ void *run_prefilter(void *v) {
 		tmp_feature.dropped = sf.dropped;
 
 		// Offset from tile coordinates back to world coordinates
-		unsigned sx = 0, sy = 0;
+		long long sx = 0, sy = 0;
 		if (rpa->z != 0) {
-			sx = rpa->tx << (GLOBAL_DETAIL - rpa->z);
-			sy = rpa->ty << (GLOBAL_DETAIL - rpa->z);
+			sx = (long long) rpa->tx << (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;