Add Blue Marble Next Gen plugin and tile rendering code

[grits] / src / gis-opengl.c

diff --git a/src/gis-opengl.c b/src/gis-opengl.c
index 03a8f2f1e43c54fed4735fd9fe0dbdfac3299eb4..4d3b7e4b98b212552f1a151dba83ed399e78d42f 100644 (file)
--- a/src/gis-opengl.c
+++ b/src/gis-opengl.c
@@ -271,6 +271,70 @@ void gis_opengl_center_position(GisOpenGL *self, gdouble lat, gdouble lon, gdoub
        glTranslatef(0, 0, elev2rad(elev));
 }
 
+void gis_opengl_render_tile(GisOpenGL *self, GisTile *tile)
+{
+       if (!tile || !tile->data)
+               return;
+       GList *triangles = roam_sphere_get_intersect(self->sphere,
+                       tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+       if (!triangles)
+               g_warning("GisOpenGL: render_tiles - No triangles to draw: edges=%f,%f,%f,%f",
+                       tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+       //g_message("rendering %4d triangles for tile edges=%7.2f,%7.2f,%7.2f,%7.2f",
+       //              g_list_length(triangles), tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+       for (GList *cur = triangles; cur; cur = cur->next) {
+               RoamTriangle *tri = cur->data;
+
+               gdouble lat[3] = {tri->p.r->lat, tri->p.m->lat, tri->p.l->lat};
+               gdouble lon[3] = {tri->p.r->lon, tri->p.m->lon, tri->p.l->lon};
+
+               if (lon[0] < -90 || lon[1] < -90 || lon[2] < -90) {
+                       if (lon[0] > 90) lon[0] -= 360;
+                       if (lon[1] > 90) lon[1] -= 360;
+                       if (lon[2] > 90) lon[2] -= 360;
+               }
+
+               gdouble n = tile->edge.n;
+               gdouble s = tile->edge.s;
+               gdouble e = tile->edge.e;
+               gdouble w = tile->edge.w;
+
+               gdouble londist = e - w;
+               gdouble latdist = n - s;
+
+               gdouble xy[][3] = {
+                       {(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},
+               };
+
+               glEnable(GL_TEXTURE_2D);
+               glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
+               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);
+               glNormal3dv(tri->p.l->norm); glTexCoord2dv(xy[2]); glVertex3dv((double*)tri->p.l);
+               glEnd();
+       }
+       g_list_free(triangles);
+}
+
+void gis_opengl_render_tiles(GisOpenGL *opengl, GisTile *tile)
+{
+       /* Only render children if possible */
+       gboolean has_children = TRUE;
+       GisTile *child;
+       gis_tile_foreach(tile, child)
+               if (!child || !child->data)
+                       has_children = FALSE;
+       if (has_children)
+               /* Only render children */
+               gis_tile_foreach(tile, child)
+                       gis_opengl_render_tiles(opengl, child);
+       else
+               /* No children, render this tile */
+               gis_opengl_render_tile(opengl, tile);
+}
 void gis_opengl_redraw(GisOpenGL *self)
 {
        g_debug("GisOpenGL: redraw");