From d68d3b2782f5042f879b2449e5b2790dba48bf5c Mon Sep 17 00:00:00 2001
From: Ralph Caraveo <deckarep@gmail.com>
Date: Sun, 3 Nov 2024 17:16:31 -0800
Subject: [PATCH] Prototype of scaled background, a dungeon twice as large.
 Additionally, working on background animation so the field doesn't fill like
 it's simply floating

---
 zsrc/audio.zig  |  2 ++
 zsrc/game.zig   |  3 ++-
 zsrc/render.zig | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 zsrc/res.zig    |  8 +++++--
 zsrc/ui.zig     |  2 +-
 5 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/zsrc/audio.zig b/zsrc/audio.zig
index eb26b96..f55379a 100644
--- a/zsrc/audio.zig
+++ b/zsrc/audio.zig
@@ -48,6 +48,8 @@ pub fn stopBgm() void {
     nowBgmId = null;
 }
 
+/// randomBgm selects a random background music track from 1.. because track
+/// 0 is reserved for the game menu.
 pub fn randomBgm() void {
     const r: usize = @intCast(hlp.randInt(1, res.bgmsPath.len - 1));
     playBgm(r);
diff --git a/zsrc/game.zig b/zsrc/game.zig
index 7f04af8..fcbc708 100644
--- a/zsrc/game.zig
+++ b/zsrc/game.zig
@@ -1175,7 +1175,8 @@ fn initGame(localPlayers: c_int, remotePlayers: c_int, localFirst: bool) !void {
     }
     try ren.initInfo();
     // create map
-    mp.initRandomMap(0.7, 7, GAME_TRAP_RATE);
+    //mp.initRandomMap(0.7, 7, GAME_TRAP_RATE); // Original
+    mp.initRandomMap(0.6, 3, GAME_TRAP_RATE);
 
     clearItemMap();
 
diff --git a/zsrc/render.zig b/zsrc/render.zig
index 4efb5dc..a855e8e 100644
--- a/zsrc/render.zig
+++ b/zsrc/render.zig
@@ -34,6 +34,9 @@ const hlp = @import("helper.zig");
 const gAllocator = @import("alloc.zig").gAllocator;
 
 pub const ANIMATION_LINK_LIST_NUM = 16;
+
+/// NOTE: these render list act as layers where MAP_ID is drawn first.
+/// and UI_ID is drawn last (on top).
 pub const RENDER_LIST_MAP_ID = 0;
 pub const RENDER_LIST_MAP_SPECIAL_ID = 1;
 pub const RENDER_LIST_MAP_ITEMS_ID = 2;
@@ -42,6 +45,7 @@ pub const RENDER_LIST_SPRITE_ID = 4;
 pub const RENDER_LIST_EFFECT_ID = 5;
 pub const RENDER_LIST_MAP_FOREWALL = 6;
 pub const RENDER_LIST_UI_ID = 7;
+
 pub const RENDER_BUFFER_SIZE = 1 << 16;
 pub const RENDER_HP_BAR_HEIGHT = 3;
 pub const RENDER_HP_BAR_WIDTH = 20;
@@ -664,10 +668,63 @@ fn renderFps() void {
     _ = renderCenteredText(&res.texts[res.textList.len + fpsUsize], 300, 10, 1);
 }
 
+const star = struct {
+    speed: c_int,
+    scale: c_int,
+    frame: c_int,
+};
+
+const fieldSize = 1000;
+var starSpeeds: [fieldSize]star = undefined;
+var starPts: [fieldSize]c.SDL_Point = undefined;
+
+var starFieldInited: bool = false;
+
+fn renderStarField() void {
+    if (!starFieldInited) {
+        var initial_value: [fieldSize]star = undefined;
+        for (&initial_value, 0..) |*st, idx| {
+            st.* = star{
+                .speed = hlp.randInt(1, 2),
+                .scale = hlp.randInt(2, 3),
+                .frame = hlp.randInt(0, 5),
+            };
+            starPts[idx].x = hlp.randInt(0, res.SCREEN_WIDTH * res.SCREEN_FACTOR);
+            starPts[idx].y = hlp.randInt(0, res.SCREEN_WIDTH * res.SCREEN_FACTOR);
+        }
+        starSpeeds = initial_value;
+        starFieldInited = true;
+    }
+
+    // Draw star field.
+    for (&starPts, 0..) |*pt, idx| {
+        const txt = res.textures[176]; // Shine
+        const frame = starSpeeds[idx].frame;
+        const src: c.SDL_Rect = txt.crops[@intCast(frame)];
+        const dst: c.SDL_Rect = .{ .x = pt.x, .y = pt.y, .w = 32 * starSpeeds[idx].scale, .h = 32 * starSpeeds[idx].scale };
+
+        _ = c.SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
+        _ = c.SDL_RenderCopy(renderer, txt.origin, &src, &dst);
+
+        if (pt.x > (res.SCREEN_WIDTH * res.SCREEN_FACTOR)) {
+            pt.x = 0;
+        }
+
+        pt.x += starSpeeds[idx].speed;
+        if (hlp.randDouble() < 0.1) starSpeeds[idx].frame += 1;
+
+        if (starSpeeds[idx].frame > 5) {
+            starSpeeds[idx].frame = 0;
+        }
+    }
+}
+
 pub fn render() !void {
     _ = c.SDL_SetRenderDrawColor(renderer, 25, 17, 23, 255);
     _ = c.SDL_RenderClear(renderer);
 
+    renderStarField();
+
     for (0..ANIMATION_LINK_LIST_NUM) |i| {
         updateAnimationLinkList(&animationsList[i]);
         if (i == RENDER_LIST_SPRITE_ID) {
diff --git a/zsrc/res.zig b/zsrc/res.zig
index 2a12800..0c2270b 100644
--- a/zsrc/res.zig
+++ b/zsrc/res.zig
@@ -220,6 +220,7 @@ pub const SPRITE_GREEN_HOOD_SKEL = 21;
 // Audio
 pub const AUDIO_BGM_SIZE = 16;
 pub const AUDIO_SOUND_SIZE = 256;
+
 pub const AUDIO_WIN = 0;
 pub const AUDIO_LOSE = 1;
 pub const AUDIO_POWERLOSS = 2;
@@ -260,8 +261,11 @@ pub const AUDIO_BOW_HIT = 35;
 // End Resource ID
 
 pub const UNIT = 32;
-pub const SCREEN_WIDTH = 1440;
-pub const SCREEN_HEIGHT = 960;
+
+// Suprisingly, the game works just as well when the SCREEN_WIDTH/HEIGHT are multiplied by 2.
+pub const SCREEN_FACTOR = 2;
+pub const SCREEN_WIDTH = 1440 * SCREEN_FACTOR;
+pub const SCREEN_HEIGHT = 960 * SCREEN_FACTOR;
 pub const n = SCREEN_WIDTH / UNIT;
 pub const m = SCREEN_HEIGHT / UNIT;
 
diff --git a/zsrc/ui.zig b/zsrc/ui.zig
index 787629c..aedda4a 100644
--- a/zsrc/ui.zig
+++ b/zsrc/ui.zig
@@ -137,7 +137,7 @@ fn chooseOptions(optionsNum: c_int, options: []const *tps.Text) !c_int {
 
         // Wedge in Zig-Edition
         // by @deckarep text.
-        _ = ren.renderCenteredText(&res.texts[17], res.SCREEN_WIDTH / 2, 920, 1);
+        _ = ren.renderCenteredText(&res.texts[17], res.SCREEN_WIDTH / 2, 920 * res.SCREEN_FACTOR, 1);
 
         // Update Screen
         c.SDL_RenderPresent(ren.renderer);