From: Andy Spencer <andy753421@gmail.com>
Date: Mon, 19 Apr 2010 06:27:17 +0000 (+0000)
Subject: Add z-index to tiles
X-Git-Tag: v0.4~20
X-Git-Url: http://pileus.org/git/?p=grits;a=commitdiff_plain;h=14c34a746fc94a9e5477d081275f04bd1c8b5d6d;hp=bbf8154058e9cbae03ebb55cd92f804db4f490aa

Add z-index to tiles

Tiles are still drawn on the ground, Z-indexes are used as polygon
offsets so that you can draw things like composite radar images above
the satellite imagery.
---

diff --git a/src/gis-opengl.c b/src/gis-opengl.c
index 9f1940b..57cfb47 100644
--- a/src/gis-opengl.c
+++ b/src/gis-opengl.c
@@ -178,7 +178,9 @@ static void _draw_tile(GisOpenGL *opengl, GisTile *tile, GList *triangles)
 		if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
 
 		glEnable(GL_TEXTURE_2D);
+		glEnable(GL_POLYGON_OFFSET_FILL);
 		glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
+		glPolygonOffset(0, -tile->zindex);
 		glBegin(GL_TRIANGLES);
 		glNormal3dv(tri->p.r->norm); glTexCoord2dv(xy[0]); glVertex3dv((double*)tri->p.r);
 		glNormal3dv(tri->p.m->norm); glTexCoord2dv(xy[1]); glVertex3dv((double*)tri->p.m);
diff --git a/src/objects/gis-tile.h b/src/objects/gis-tile.h
index 4ebf7ef..e2b7252 100644
--- a/src/objects/gis-tile.h
+++ b/src/objects/gis-tile.h
@@ -38,6 +38,9 @@ struct _GisTile {
 	/* Pointer to the tile data */
 	gpointer data;
 
+	/* Pointer to the tile data */
+	gint zindex;
+
 	/* North,South,East,West limits */
 	GisBBox edge;
 
diff --git a/src/plugins/sat.c b/src/plugins/sat.c
index 66150be..9e1af30 100644
--- a/src/plugins/sat.c
+++ b/src/plugins/sat.c
@@ -179,7 +179,7 @@ GisPluginSat *gis_plugin_sat_new(GisViewer *viewer)
 			G_CALLBACK(_on_location_changed), sat);
 
 	/* Add renderers */
-	gis_viewer_add(viewer, GIS_OBJECT(sat->tiles), GIS_LEVEL_WORLD, 0);
+	gis_viewer_add(viewer, GIS_OBJECT(sat->tiles), GIS_LEVEL_WORLD, FALSE);
 
 	return sat;
 }