Merge pull request 'Fix Doom fire animation; add flame height control' (#792) from asterane/ly:doom-fire-refresh into master (fixes #784)

Reviewed-on: https://codeberg.org/fairyglade/ly/pulls/792
Reviewed-by: AnErrupTion <anerruption@disroot.org>

res/config.ini

@@ -104,13 +104,19 @@ colormix_col3 = 0x20000000
 # Available inputs: info_line, session, login, password
 default_input = login
 
-# DOOM animation top color (low intensity flames)
-doom_top_color = 0x00FF0000
+# DOOM animation fire height (1 thru 9)
+doom_fire_height = 6
 
-# DOOM animation middle color (medium intensity flames)
-doom_middle_color = 0x00FFFF00
+# DOOM animation fire spread (0 thru 4)
+doom_fire_spread = 2
 
-# DOOM animation bottom color (high intensity flames)
+# DOOM animation custom top color (low intensity flames)
+doom_top_color = 0x009F2707
+
+# DOOM animation custom middle color (medium intensity flames)
+doom_middle_color = 0x00C78F17
+
+# DOOM animation custom bottom color (high intensity flames)
 doom_bottom_color = 0x00FFFFFF
 
 # Error background color id

src/animations/Doom.zig

@@ -7,21 +7,22 @@ const TerminalBuffer = @import("../tui/TerminalBuffer.zig");
 const Doom = @This();
 
 pub const STEPS = 12;
+pub const HEIGHT_MAX = 9;
+pub const SPREAD_MAX = 4;
 
 allocator: Allocator,
 terminal_buffer: *TerminalBuffer,
 buffer: []u8,
+height: u8,
+spread: u8,
 fire: [STEPS + 1]Cell,
 
-pub fn init(allocator: Allocator, terminal_buffer: *TerminalBuffer, top_color: u32, middle_color: u32, bottom_color: u32) !Doom {
+pub fn init(allocator: Allocator, terminal_buffer: *TerminalBuffer, top_color: u32, middle_color: u32, bottom_color: u32, fire_height: u8, fire_spread: u8) !Doom {
     const buffer = try allocator.alloc(u8, terminal_buffer.width * terminal_buffer.height);
     initBuffer(buffer, terminal_buffer.width);
 
-    return .{
-        .allocator = allocator,
-        .terminal_buffer = terminal_buffer,
-        .buffer = buffer,
-        .fire = [_]Cell{
+    const levels =
+        [_]Cell{
             Cell.init(' ', TerminalBuffer.Color.DEFAULT, TerminalBuffer.Color.DEFAULT),
             Cell.init(0x2591, top_color, TerminalBuffer.Color.DEFAULT),
             Cell.init(0x2592, top_color, TerminalBuffer.Color.DEFAULT),
@@ -35,7 +36,15 @@ pub fn init(allocator: Allocator, terminal_buffer: *TerminalBuffer, top_color: u
             Cell.init(0x2592, bottom_color, middle_color),
             Cell.init(0x2593, bottom_color, middle_color),
             Cell.init(0x2588, bottom_color, middle_color),
-        },
+        };
+
+    return .{
+        .allocator = allocator,
+        .terminal_buffer = terminal_buffer,
+        .buffer = buffer,
+        .height = @min(HEIGHT_MAX, fire_height),
+        .spread = @min(SPREAD_MAX, fire_spread),
+        .fire = levels,
     };
 }
 
@@ -57,20 +66,35 @@ fn draw(self: *Doom) void {
     for (0..self.terminal_buffer.width) |x| {
         // We start from 1 so that we always have the topmost line when spreading fire
         for (1..self.terminal_buffer.height) |y| {
-            // Get current cell
+            // Get index of current cell in fire level buffer
             const from = y * self.terminal_buffer.width + x;
-            const cell_index = self.buffer[from];
 
-            // Spread fire
-            const propagate = self.terminal_buffer.random.int(u1);
-            const to = from - self.terminal_buffer.width; // Get the line above
+            // Generate random data for fire propagation
+            const rand_loss = self.terminal_buffer.random.intRangeAtMost(u8, 0, HEIGHT_MAX);
+            const rand_spread = self.terminal_buffer.random.intRangeAtMost(u8, 0, self.spread * 2);
 
-            self.buffer[to] = if (cell_index > 0) cell_index - propagate else cell_index;
+            // Select semi-random target cell
+            const to = from -| self.terminal_buffer.width + self.spread -| rand_spread;
+            const to_x = to % self.terminal_buffer.width;
+            const to_y = to / self.terminal_buffer.width;
 
-            // Put the cell
-            const cell = self.fire[cell_index];
-            cell.put(x, y);
+            // Get fire level of current cell
+            const level_buf_from = self.buffer[from];
+
+            // Choose new fire level and store in level buffer
+            const level_buf_to = level_buf_from -| @intFromBool(rand_loss >= self.height);
+            self.buffer[to] = level_buf_to;
+
+            // Send known fire levels to terminal buffer
+            const from_cell = self.fire[level_buf_from];
+            const to_cell = self.fire[level_buf_to];
+            from_cell.put(x, y);
+            to_cell.put(to_x, to_y);
         }
+
+        // Draw bottom line (fire source)
+        const src_cell = self.fire[STEPS];
+        src_cell.put(x, self.terminal_buffer.height - 1);
     }
 }
 

src/config/Config.zig

@@ -29,6 +29,8 @@ colormix_col1: u32 = 0x00FF0000,
 colormix_col2: u32 = 0x000000FF,
 colormix_col3: u32 = 0x20000000,
 default_input: Input = .login,
+doom_fire_height: u8 = 6,
+doom_fire_spread: u8 = 2,
 doom_top_color: u32 = 0x00FF0000,
 doom_middle_color: u32 = 0x00FFFF00,
 doom_bottom_color: u32 = 0x00FFFFFF,

src/main.zig

@@ -354,7 +354,7 @@ pub fn main() !void {
             animation = dummy.animation();
         },
         .doom => {
-            var doom = try Doom.init(allocator, &buffer, config.doom_top_color, config.doom_middle_color, config.doom_bottom_color);
+            var doom = try Doom.init(allocator, &buffer, config.doom_top_color, config.doom_middle_color, config.doom_bottom_color, config.doom_fire_height, config.doom_fire_spread);
             animation = doom.animation();
         },
         .matrix => {