Fix bugs in GritsTile

- Prevent black spots when tiles are hidden by a thread while they are
  being drawn by the main thread.

- Add hack to draw maps in a lighter color

diff --git a/src/objects/grits-tile.c b/src/objects/grits-tile.c
index cba5b7579eec9f16cef3a51715ac3a07d439ba45..736e374df12812826bb053e30357994c72fe1267 100644 (file)
--- a/src/objects/grits-tile.c
+++ b/src/objects/grits-tile.c
@@ -430,7 +430,13 @@ static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *tri
                        glActiveTexture(GL_TEXTURE1);
                        glEnable(GL_TEXTURE_2D);
                        glBindTexture(GL_TEXTURE_2D, grits_tile_mask);
-                       glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+                       glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+                       /* Hack to show maps tiles with better color */
+                       float material_emission[] = {0.5, 0.5, 0.5, 1.0};
+                       glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, material_emission);
+
+                       glEnable(GL_BLEND);
                }
 
                /* Draw triangle */
@@ -447,29 +453,38 @@ static void grits_tile_draw_one(GritsTile *tile, GritsOpenGL *opengl, GList *tri
 }
 
 /* Draw the tile */
-static void grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
+static gboolean grits_tile_draw_rec(GritsTile *tile, GritsOpenGL *opengl)
 {
        if (!tile || !tile->data || GRITS_OBJECT(tile)->hidden)
-               return;
+               return FALSE;
 
-       /* Only draw children if possible */
-       gboolean has_all_children = TRUE;
-       GritsTile *child;
-       grits_tile_foreach(tile, child)
-               if (!child || !child->data || GRITS_OBJECT(child)->hidden)
-                       has_all_children = FALSE;
-
-       /* Draw parent tile underneath */
-       if (!has_all_children) {
-               GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
-                               tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
-               grits_tile_draw_one(tile, opengl, triangles);
-               g_list_free(triangles);
-       }
+       GritsTile *child = NULL;
+       gboolean   done  = FALSE;
+       while (!done) {
+               /* Only draw children if possible */
+               gboolean draw_parent = FALSE;
+               grits_tile_foreach(tile, child)
+                       if (!child || !child->data || GRITS_OBJECT(child)->hidden)
+                               draw_parent = TRUE;
+
+               /* Draw parent tile underneath */
+               if (draw_parent) {
+                       GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
+                                       tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+                       grits_tile_draw_one(tile, opengl, triangles);
+                       g_list_free(triangles);
+               }
 
-       /* Draw child tiles */
-       grits_tile_foreach(tile, child)
-               grits_tile_draw_rec(child, opengl);
+               /* Draw child tiles */
+               gboolean drew_all_children = TRUE;
+               grits_tile_foreach(tile, child)
+                       if (!grits_tile_draw_rec(child, opengl))
+                               drew_all_children = FALSE;
+
+               /* Check if tiles were hidden by a thread while drawing */
+               done = draw_parent || drew_all_children;
+       }
+       return TRUE;
 }
 
 static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
@@ -477,7 +492,7 @@ static void grits_tile_draw(GritsObject *tile, GritsOpenGL *opengl)
        glEnable(GL_DEPTH_TEST);
        glDepthFunc(GL_LESS);
        glEnable(GL_ALPHA_TEST);
-       glAlphaFunc(GL_GREATER, 0.5);
+       glAlphaFunc(GL_GREATER, 0.1);
        grits_tile_draw_rec(GRITS_TILE(tile), opengl);
 }