From 8d41ee397d3c159d3843b911e3dc6095700d3e5e Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Wed, 1 Mar 2023 08:00:43 +0000
Subject: Pass an optional offset to the viewport

---
 src/Game.hs     |  2 +-
 src/Game/Map.hs | 11 ++++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/Game.hs b/src/Game.hs
index d1552d0..537b889 100644
--- a/src/Game.hs
+++ b/src/Game.hs
@@ -190,7 +190,7 @@ gameLoop = do
       -- render map and entities
       void $ do
         -- set the SDL viewport
-        viewport <- M.viewport renderer map' px py (fromIntegral gameWidth) (fromIntegral gameHeight - H.height)
+        viewport <- M.viewport renderer map' px py (fromIntegral gameWidth) (fromIntegral gameHeight - H.height) (Just (0, H.height))
         M.render renderer map' viewport
         E.renderVisible renderer updated viewport
 
diff --git a/src/Game/Map.hs b/src/Game/Map.hs
index 5da8133..8445a1b 100644
--- a/src/Game/Map.hs
+++ b/src/Game/Map.hs
@@ -13,7 +13,7 @@ module Game.Map
 where
 
 import Control.Monad
-import Data.Maybe (mapMaybe)
+import Data.Maybe (fromMaybe, mapMaybe)
 import qualified Game.Utils as U
 import SDL (($=))
 import qualified SDL
@@ -169,8 +169,9 @@ totalBatteries m = length $ filter isBattery (objects m)
 
 -- | Set the SDL viewport based on the map and the provided viewport coordinates.
 -- It returns the viewport to be used by render.
-viewport :: SDL.Renderer -> Map -> Int -> Int -> Int -> Int -> IO Viewport
-viewport renderer (Map mapData _) vx vy vw vh = do
+-- Optionally an offset can be provided.
+viewport :: SDL.Renderer -> Map -> Int -> Int -> Int -> Int -> Maybe (Int, Int) -> IO Viewport
+viewport renderer (Map mapData _) vx vy vw vh offs = do
   SDL.rendererViewport renderer $= Just mapRect
   pure $ Viewport newx newy vw vh
   where
@@ -187,8 +188,8 @@ viewport renderer (Map mapData _) vx vy vw vh = do
     newx = min (if fx + halfViewportWidth > mapWidth then mapWidth - vw else fx) (mapWidth - vw)
     newy = min (if fy + halfViewportHeight > mapHeight then mapHeight - vh else fy) (mapHeight - vh)
 
-    -- FIXME: hardcoded size of the HUD; perhaps we need to pass x, y offsets to the viewport
-    mapRect = U.rect (-newx) (16 - newy) (newx + vw) vh
+    (offsx, offsy) = fromMaybe (0, 0) offs
+    mapRect = U.rect (offsx - newx) (offsy - newy) (newx + vw) vh
 
 -- | Render a map.
 -- Requires a Viewport from viewport.
-- 
cgit v1.2.3