Bug 560: Fix 1-pixel gaps between tiles near hidden areas.

[supertux.git] / src / object / tilemap.cpp

diff --git a/src/object/tilemap.cpp b/src/object/tilemap.cpp
index 0adbb86..4a144e6 100644 (file)
--- a/src/object/tilemap.cpp
+++ b/src/object/tilemap.cpp
@@ -188,7 +188,7 @@ TileMap::update(float elapsed_time)
 void
 TileMap::draw(DrawingContext& context)
 {
-  // skip draw if current opacity is set to 0.0
+  // skip draw if current opacity is 0.0
   if (current_alpha == 0.0) return;
 
   context.push_transform();
@@ -200,30 +200,39 @@ TileMap::draw(DrawingContext& context)
   if(drawing_effect != 0) context.set_drawing_effect(drawing_effect);
   if(current_alpha != 1.0) context.set_alpha(current_alpha);
 
+  /* Force the translation to be an integer so that the tiles appear sharper.
+   * For consistency (i.e., to avoid 1-pixel gaps), this needs to be done even
+   * for solid tilemaps that are guaranteed to have speed 1.
+   * FIXME Force integer translation for all graphics, not just tilemaps. */
   float trans_x = roundf(context.get_translation().x);
   float trans_y = roundf(context.get_translation().y);
   context.set_translation(Vector(int(trans_x * speed_x),
                                  int(trans_y * speed_y)));
 
-  /** if we don't round here, we'll have a 1 pixel gap on screen sometimes.
-   * I have no idea why */
-  float start_x = int((roundf(context.get_translation().x) - roundf(x_offset)) / 32) * 32 + roundf(x_offset);
-  float start_y = int((roundf(context.get_translation().y) - roundf(y_offset)) / 32) * 32 + roundf(y_offset);
-  float end_x = std::min(start_x + SCREEN_WIDTH + 32, float(width * 32 + roundf(x_offset)));
-  float end_y = std::min(start_y + SCREEN_HEIGHT + 32, float(height * 32 + roundf(y_offset)));
-  int tsx = int((start_x - roundf(x_offset)) / 32); // tilestartindex x
-  int tsy = int((start_y - roundf(y_offset)) / 32); // tilestartindex y
+  int tsx = int((context.get_translation().x - x_offset) / 32); // tilestartindex x
+  int tsy = int((context.get_translation().y - y_offset) / 32); // tilestartindex y
+  tsx = std::max(tsx, 0);
+  tsy = std::max(tsy, 0);
+  float start_x = tsx * 32 + x_offset;
+  float start_y = tsy * 32 + y_offset;
+  float end_x = start_x + SCREEN_WIDTH + 32;
+  float end_y = start_y + SCREEN_HEIGHT + 32;
 
   Vector pos;
   int tx, ty;
-  for(pos.x = start_x, tx = tsx; pos.x < end_x; pos.x += 32, ++tx) {
-    for(pos.y = start_y, ty = tsy; pos.y < end_y; pos.y += 32, ++ty) {
-      if ((tx < 0) || (ty < 0) || (tiles[ty*width + tx] == 0)) continue;
-      const Tile* tile = tileset->get(tiles[ty*width + tx]);
+
+  for(pos.x = start_x, tx = tsx; (pos.x < end_x) && (tx < width); pos.x += 32, ++tx) {
+    for(pos.y = start_y, ty = tsy; (pos.y < end_y) && (ty < height); pos.y += 32, ++ty) {
+      int index = ty*width + tx;
+      assert (index >= 0);
+      assert (index < (width * height));
+
+      if (tiles[index] == 0) continue;
+      const Tile* tile = tileset->get(tiles[index]);
       assert(tile != 0);
       tile->draw(context, pos, z_pos);
-    }
-  }
+    } /* for (pos y) */
+  } /* for (pos x) */
 
   if(draw_target != DrawingContext::NORMAL) {
     context.pop_target();
@@ -256,8 +265,8 @@ void
 TileMap::expose(HSQUIRRELVM vm, SQInteger table_idx)
 {
   if (name.empty()) return;
-  scripting::TileMap* interface = new scripting::TileMap(this);
-  expose_object(vm, table_idx, interface, name, true);
+  scripting::TileMap* _this = new scripting::TileMap(this);
+  expose_object(vm, table_idx, _this, name, true);
 }
 
 void