scrolling kinda works if you squint!

Signed-off-by: Christine Dodrill <me@christine.website>

maps/RPGmap.tmx

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<map version="1.9" tiledversion="1.9.0" orientation="orthogonal" renderorder="right-down" width="40" height="40" tilewidth="8" tileheight="8" infinite="0" nextlayerid="6" nextobjectid="39">
+<map version="1.4" tiledversion="1.4.3" orientation="orthogonal" renderorder="right-down" width="40" height="40" tilewidth="8" tileheight="8" infinite="0" nextlayerid="6" nextobjectid="39">
  <editorsettings>
   <export target="RPGmap.json" format="json"/>
  </editorsettings>

src/main.zig

@@ -19,7 +19,6 @@ var mara_frame: bool = false;
 var mara_box: Rect = Rect{ .base = map.start_point, .width = 16, .height = 16 };
 var mara_speed: i16 = 0;
 var old_speed: i16 = 0;
-var screen = Rect{ .base = Point{ .x = 0, .y = 0 }, .width = 160, .height = 160 };
 
 const screen_width = 20;
 const screen_height = 20;
@@ -35,7 +34,7 @@ var camera = Point{ .x = 0, .y = 0 };
 var state: sh0rk.State = .Gameplay;
 
 fn world_to_screen(p: Point) Point {
-    p.sub(camera);
+    return p.sub(camera);
 }
 
 fn screen_to_world(p: Point) Point {
@@ -69,10 +68,10 @@ fn bonk() void {
         },
     );
 
-    sound_timer = 12;
+    sound_timer = 30;
 }
 
-fn drawMap() !void {
+fn map_colors() void {
     switch (map.tileset) {
         .Dungeon => {
             w4.m.colors.* = .{
@@ -91,58 +90,44 @@ fn drawMap() !void {
             };
         },
     }
-    if (!done) {
-        var buf = fmt.bufPrint(&textBuf, "camera: {},{}", .{ camera.x, camera.y }) catch unreachable;
-        w4.trace(buf);
 }
 
-    var startCol: i32 = @divTrunc(camera.x, tile_size);
-    var endCol = startCol + screen_width;
-    var startRow: i32 = @divTrunc(camera.y, tile_size);
-    var endRow = startRow + screen_height;
+fn drawMap() !void {
+    map_colors();
 
-    var offsetX = startCol * tile_size;
-    var offsetY = startRow * tile_size;
+    var startCol = @divTrunc(camera.x, tile_size);
+    var endCol = startCol + screen_width;
+    var startRow = @divTrunc(camera.y, tile_size);
+    var endRow = startRow + screen_height;
 
     if (!done) {
         var buf = fmt.bufPrint(&textBuf, "{},{}: {},{}", .{ startCol, startRow, endCol, endRow }) catch unreachable;
         w4.trace(buf);
     }
-    if (!done) {
-        var buf = fmt.bufPrint(&textBuf, "offx: {}, offy: {}", .{ offsetX, offsetY }) catch unreachable;
-        w4.trace(buf);
-    }
 
-    var col: i32 = startCol;
+    var col: i16 = startCol;
     while (col < endCol) {
-        var row: i32 = startRow;
+        var row: i16 = startRow;
         defer col += 1;
         while (row < endRow) {
             defer row += 1;
 
-            var tile = map.get_tile(@intCast(u32, col), @intCast(u32, row));
-
-            var x = (row - startCol) * tile_size - offsetX;
-            var y = (col - startRow) * tile_size - offsetY;
-
-            if (x < 0) {
-                x = x * -1;
-            }
-            if (y < 0) {
-                y = y * -1;
-            }
-
+            if (col < map.width and row < map.height) {
+                var tile = map.get_tile(col, row);
+                var world = Point{ .x = col * 8, .y = row * 8 };
+                var scr = world_to_screen(world);
                 if(!done) {
-                var buf = fmt.bufPrint(&textBuf, "{},{}: {}: {},{}", .{ col, row, tile, x, y }) catch unreachable;
+                    var buf = fmt.bufPrint(&textBuf, "{},{}: {},{}", .{ row, col, scr.x, scr.y }) catch unreachable;
                     w4.trace(buf);
                 }
 
-            draw_tile(tile, @intCast(u32, x), @intCast(u32, y));
+                draw_tile(tile, scr.y,  scr.x);
+            }
         }
     }
 }
 
-fn draw_tile(tile: u32, x: u32, y: u32) void {
+fn draw_tile(tile: u32, x: i32, y: i32) void {
     if (tile == 0) {
         w4.rect(x, y, 8, 8);
         return;
@@ -158,8 +143,8 @@ fn draw_tile(tile: u32, x: u32, y: u32) void {
             y,
             8,
             8,
-            @intCast(u32, tileX) * 8,
-            @intCast(u32, tileY) * 8,
+            tileX * 8,
+            tileY * 8,
             sprites.kenney_rpg_width,
             w4.BlitFlags{ .two_bits = true },
         ),
@@ -169,8 +154,8 @@ fn draw_tile(tile: u32, x: u32, y: u32) void {
             y,
             8,
             8,
-            @intCast(u32, tileX) * 8,
-            @intCast(u32, tileY) * 8,
+            tileX * 8,
+            tileY * 8,
             sprites.dungeon_width,
             w4.BlitFlags{ .two_bits = true },
         ),
@@ -197,16 +182,16 @@ fn move_mara(gamepad: w4.GamePad) void {
 
     switch (mara_direction) {
         .Up => {
-            mara_box.base.y -= mara_speed;
+            camera.x -= mara_speed;
         },
         .Down => {
-            mara_box.base.y += mara_speed;
+            camera.x += mara_speed;
         },
         .Left => {
-            mara_box.base.x -= mara_speed;
+            camera.y -= mara_speed;
         },
         .Right => {
-            mara_box.base.x += mara_speed;
+            camera.y += mara_speed;
         },
     }
 }
@@ -232,7 +217,7 @@ fn title() !void {
 }
 
 const story = "After defeating\nthe evil mage,\nMalto was at\npeace.\n\nOne day Mara was\nwalking along the\nbeach when she saw\nthe killing stone\nwas split in two.\nTamamo-no-Mae was\nfree to wreak havoc\nacross the land.\n\nHelp us again Mara!\nSave Kanar from\nTamamo-no-Mae!\n\nPress x.";
-var story_idx: usize = 0;
+var story_idx: u16 = 0;
 var story_counter: u8 = 4;
 
 fn storydump() !void {
@@ -378,7 +363,7 @@ fn draw_mara() void {
         flags.flip_x = true;
     }
 
-    if (frame_count % 32 == 0 and mara_speed > 0) {
+    if (frame_count % 16 == 0 and mara_speed > 0) {
         mara_frame = !mara_frame;
     }
 
@@ -390,12 +375,12 @@ fn draw_mara() void {
     };
     var step: u32 = if (mara_frame) 1 else 0;
 
-    w4.blitSub(&sprites.Mara, @intCast(u32, mara_box.base.x), @intCast(u32, mara_box.base.y), 16, 16, 16 * (frame + step), 0, 96, flags);
+    w4.blitSub(&sprites.Mara, mara_box.base.x, mara_box.base.y, 16, 16, 16 * (frame + step), 0, 96, flags);
 }
 
 pub fn panic(msg: []const u8, st: ?*std.builtin.StackTrace) noreturn {
     _ = st;
     w4.trace("!!! PANIC !!!");
     w4.trace(msg);
-    while (true) {}
+    unreachable;
 }

src/maps/dungeon.zig

@@ -10,8 +10,14 @@ const Rect = sh0rk.Rect;
 pub const width = 20;
 pub const height = 20;
 
-pub fn get_tile(x: u32, y: u32) u9 {
-    return data[x * height + y];
+pub fn get_tile(x: i32, y: i32) u9 {
+    if (x < 0 or y < 0) {
+        return 0;
+    }
+    if (x >= width or y >= height) {
+        return 0;
+    }
+    return data[@intCast(u32, x) * height + @intCast(u32, y)];
 }
 pub const tileset: Tileset = .Dungeon;
 pub const ts_width = 14;

src/maps/overworld.zig

@@ -10,8 +10,14 @@ const Rect = sh0rk.Rect;
 pub const width = 40;
 pub const height = 40;
 
-pub fn get_tile(x: u32, y: u32) u9 {
-    return data[x * height + y];
+pub fn get_tile(x: i32, y: i32) u9 {
+    if (x < 0 or y < 0) {
+        return 0;
+    }
+    if (x >= width or y >= height) {
+        return 0;
+    }
+    return data[@intCast(u32, x) * height + @intCast(u32, y)];
 }
 pub const tileset: Tileset = .Rpg;
 pub const ts_width = 34;

src/tools/genmap.js

@@ -24,8 +24,14 @@ out += `const Rect = sh0rk.Rect;\n\n`;
 out += `pub const width = ${map.width};\n`;
 out += `pub const height = ${map.height};\n\n`;
 
-out += `pub fn get_tile(x: u32, y: u32) u9 {
-    return data[x * height + y];
+out += `pub fn get_tile(x: i32, y: i32) u9 {
+    if (x < 0 or y < 0) {
+        return 0;
+    }
+    if (x >= width or y >= height) {
+        return 0;
+    }
+    return data[@intCast(u32, x) * height + @intCast(u32, y)];
 }
 `;
 

src/wasm4.zig

@@ -116,8 +116,8 @@ pub const SystemFlags = packed struct {
 // └───────────────────────────────────────────────────────────────────────────┘
 
 const raw_api = struct {
-    extern fn blit(sprite: [*]const u8, x: u32, y: u32, width: u32, height: u32, flags: u32) void;
-    extern fn blitSub(sprite: [*]const u8, x: u32, y: u32, width: u32, height: u32, src_x: u32, src_y: u32, stride: u32, flags: u32) void;
+    extern fn blit(sprite: [*]const u8, x: i32, y: i32, width: u32, height: u32, flags: u32) void;
+    extern fn blitSub(sprite: [*]const u8, x: i32, y: i32, width: u32, height: u32, src_x: u32, src_y: u32, stride: u32, flags: u32) void;
     extern fn tone(frequency: u32, duration: u32, volume: u32, flags: u32) void;
 };
 
@@ -137,7 +137,7 @@ pub const BlitFlags = packed struct {
 };
 
 /// Copies pixels to the framebuffer.
-pub fn blit(sprite: []const u8, x: u32, y: u32, width: u32, height: u32, flags: BlitFlags) void {
+pub fn blit(sprite: []const u8, x: i32, y: i32, width: u32, height: u32, flags: BlitFlags) void {
     raw_api.blit(sprite.ptr, x, y, width, height, @bitCast(u32, flags));
 }
 
@@ -145,24 +145,24 @@ pub fn blit(sprite: []const u8, x: u32, y: u32, width: u32, height: u32, flags:
 /// srcX: Source X position of the sprite region.
 /// srcY: Source Y position of the sprite region.
 /// stride: Total width of the overall sprite atlas. This is typically larger than width.
-pub fn blitSub(sprite: []const u8, x: u32, y: u32, width: u32, height: u32, src_x: u32, src_y: u32, stride: u32, flags: BlitFlags) void {
+pub fn blitSub(sprite: []const u8, x: i32, y: i32, width: u32, height: u32, src_x: u32, src_y: u32, stride: u32, flags: BlitFlags) void {
     raw_api.blitSub(sprite.ptr, x, y, width, height, src_x, src_y, stride, @bitCast(u32, flags));
 }
 
 /// Draws a line between two points.
-pub extern fn line(x1: u32, y1: u32, x2: u32, y2: u32) void;
+pub extern fn line(x1: i32, y1: i32, x2: i32, y2: i32) void;
 
 /// Draws an oval (or circle).
-pub extern fn oval(x: u32, y: u32, width: u32, height: u32) void;
+pub extern fn oval(x: i32, y: i32, width: u32, height: u32) void;
 
 /// Draws a rectangle.
-pub extern fn rect(x: u32, y: u32, width: u32, height: u32) void;
+pub extern fn rect(x: i32, y: i32, width: u32, height: u32) void;
 
 /// Draws text using the built-in system font.
-pub fn text(str: []const u8, x: u32, y: u32) void {
+pub fn text(str: []const u8, x: i32, y: i32) void {
     textUtf8(str.ptr, str.len, x, y);
 }
-extern fn textUtf8(strPtr: [*]const u8, strLen: usize, x: u32, y: u32) void;
+extern fn textUtf8(strPtr: [*]const u8, strLen: usize, x: i32, y: i32) void;
 
 /// Draws a vertical line
 pub extern fn vline(x: u32, y: u32, len: u32) void;