Add z-index to tiles

[grits] / src / gis-opengl.c

diff --git a/src/gis-opengl.c b/src/gis-opengl.c
index 9f1940bdfdb5d33d177f5e81114546a81a3345fe..57cfb471e901894d3b510c9f0e3b99aabbf50b10 100644 (file)
--- 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);