Address TODOHEADmain

1 files changed, 12 insertions, 7 deletions

diff --git a/src/gfx2d.c b/src/gfx2d.c
index 14e0539..1c8b06f 100644
--- a/src/gfx2d.c
+++ b/src/gfx2d.c
@@ -651,16 +651,21 @@ static void draw_map_ortho(Gfx2d* gfx) {
   assert(gfx);
   assert(gfx->map);
 
+  // Render the tiles that the camera view rectangle intersects.
+  // +1 when computing x1,y1 because the screen dimensions need not be a
+  // multiple of the base tile dimensions.
+  const int x_tiles = gfx->screen.width / gfx->map->base_tile_width;
+  const int y_tiles = gfx->screen.height / gfx->map->base_tile_height;
+  const int x0      = gfx->camera.x / gfx->map->base_tile_width;
+  const int y0      = gfx->camera.y / gfx->map->base_tile_height;
+  const int x1      = min(gfx->map->world_width, x0 + x_tiles + 1);
+  const int y1      = min(gfx->map->world_height, y0 + y_tiles + 1);
+
   for (uint16_t l = 0; l < gfx->map->num_layers; ++l) {
     const Tm_Layer* layer = tm_map_get_layer(gfx->map, l);
 
-    // TODO: This currently renders with tile granularity. Do so instead in
-    //  terms of pixels for more accurate camera panning. The camera coordinates
-    //  are already given in pixels.
-    for (int wy = gfx->camera.y / gfx->map->base_tile_height;
-         wy < gfx->map->world_height; ++wy) {
-      for (int wx = gfx->camera.x / gfx->map->base_tile_width;
-           wx < gfx->map->world_width; ++wx) {
+    for (int wy = y0; wy < y1; ++wy) {
+      for (int wx = x0; wx < x1; ++wx) {
         const Tile tile = tm_layer_get_tile(gfx->map, layer, wx, wy);
         draw_tile_ortho(gfx, tile, wx, wy);
       }