From 37170f3b0fe9625d75a294eeef1b4442fa63a7f1 Mon Sep 17 00:00:00 2001
From: Andy Spencer <andy753421@gmail.com>
Date: Tue, 26 Jan 2010 01:05:09 +0000
Subject: [PATCH] Fix rendering at the poles

---
 src/gis-opengl.c   | 20 +++++++++++++++++++-
 src/gis-tile.c     |  7 +++++++
 src/plugins/srtm.c |  4 ++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/gis-opengl.c b/src/gis-opengl.c
index bf60862..0fff2bf 100644
--- a/src/gis-opengl.c
+++ b/src/gis-opengl.c
@@ -481,12 +481,30 @@ static void gis_opengl_render_tile(GisViewer *_self, GisTile *tile)
 		gdouble londist = e - w;
 		gdouble latdist = n - s;
 
-		gdouble xy[][3] = {
+		gdouble xy[3][2] = {
 			{(lon[0]-w)/londist, 1-(lat[0]-s)/latdist},
 			{(lon[1]-w)/londist, 1-(lat[1]-s)/latdist},
 			{(lon[2]-w)/londist, 1-(lat[2]-s)/latdist},
 		};
 
+		//if ((lat[0] == 90 && (xy[0][0] < 0 || xy[0][0] > 1)) ||
+		//    (lat[1] == 90 && (xy[1][0] < 0 || xy[1][0] > 1)) ||
+		//    (lat[2] == 90 && (xy[2][0] < 0 || xy[2][0] > 1)))
+		//	g_message("w,e=%4.f,%4.f   "
+		//	          "lat,lon,x,y="
+		//	          "%4.1f,%4.0f,%4.2f,%4.2f   "
+		//	          "%4.1f,%4.0f,%4.2f,%4.2f   "
+		//	          "%4.1f,%4.0f,%4.2f,%4.2f   ",
+		//		w,e,
+		//		lat[0], lon[0], xy[0][0], xy[0][1],
+		//		lat[1], lon[1], xy[1][0], xy[1][1],
+		//		lat[2], lon[2], xy[2][0], xy[2][1]);
+
+		/* Fix poles */
+		if (lat[0] == 90 || lat[0] == -90) xy[0][0] = 0.5;
+		if (lat[1] == 90 || lat[1] == -90) xy[1][0] = 0.5;
+		if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
+
 		glEnable(GL_TEXTURE_2D);
 		glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
 		glBegin(GL_TRIANGLES);
diff --git a/src/gis-tile.c b/src/gis-tile.c
index e265e05..6140334 100644
--- a/src/gis-tile.c
+++ b/src/gis-tile.c
@@ -142,6 +142,13 @@ GisTile *gis_tile_find(GisTile *self, gdouble lat, gdouble lon)
 	gint    row = lat_offset / lat_step;
 	gint    col = lon_offset / lon_step;
 
+	if (lon == 180) col--;
+	if (lat == -90) row--;
+
+	//if (lon == 180 || lon == -180)
+	//	g_message("lat=%f,lon=%f step=%f,%f off=%f,%f row=%d/%d,col=%d/%d",
+	//		lat,lon, lat_step,lon_step, lat_offset,lon_offset, row,rows,col,cols);
+
 	if (row < 0 || row >= rows || col < 0 || col >= cols)
 		return NULL;
 	else if (self->children[row][col] && self->children[row][col]->data)
diff --git a/src/plugins/srtm.c b/src/plugins/srtm.c
index 6e07a80..058f54d 100644
--- a/src/plugins/srtm.c
+++ b/src/plugins/srtm.c
@@ -65,6 +65,10 @@ static gdouble _height_func(gdouble lat, gdouble lon, gpointer _self)
 	guint x_flr = (int)x;
 	guint y_flr = (int)y;
 
+	//if (lon == 180 || lon == -180)
+	//	g_message("lon=%f w=%d min=%f max=%f dist=%f x=%f rem=%f flr=%d",
+	//	           lon,   w,  xmin,  xmax,  xdist,   x, x_rem, x_flr);
+
 	/* TODO: Fix interpolation at edges:
 	 *   - Pad these at the edges instead of wrapping/truncating
 	 *   - Figure out which pixels to index (is 0,0 edge, center, etc) */
-- 
2.43.2