From cf572179eaf8fd9cb4b9f2b9589a1f1898d0f05c Mon Sep 17 00:00:00 2001
From: Jason Hilder <jhilder95@gmail.com>
Date: Tue, 2 Jun 2026 08:23:26 +0200
Subject: [PATCH] Initial gui commit.

Very much WIP trying to find a good way to keep components self
contained and composable.
---
 src/gui/gui.odin    | 53 +++++++++++++++++++++++++++++++
 src/gui/screen.odin | 77 +++++++++++++++++++++++++++++++++++++++++++++
 src/main.odin       | 13 ++++----
 3 files changed, 137 insertions(+), 6 deletions(-)
 create mode 100644 src/gui/gui.odin
 create mode 100644 src/gui/screen.odin

diff --git a/src/gui/gui.odin b/src/gui/gui.odin
new file mode 100644
index 0000000..efb95c4
--- /dev/null
+++ b/src/gui/gui.odin
@@ -0,0 +1,53 @@
+package gui
+
+import m "../machine"
+import rl "vendor:raylib"
+
+// Initial window size
+WINDOW_WIDTH  :: 1920
+WINDOW_HEIGHT :: 1080
+
+// Initialize main the gui 'window'
+init_gui :: proc(s: ^m.System) {
+	rl.SetConfigFlags({.WINDOW_RESIZABLE})
+	rl.InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "raylib")
+	rl.InitAudioDevice()
+	rl.SetTargetFPS(60)
+
+	// Draw each of the components in its own window within the main window
+	for !rl.WindowShouldClose() {
+		// Recalculate layout each frame based on current window size
+		// Pass these down to gui functions so they can setup their sizes?
+		screen_width  := f32(rl.GetScreenWidth())
+		screen_height := f32(rl.GetScreenHeight())
+
+		sidebar_width := screen_width * 0.20
+
+		display_rect := rl.Rectangle{
+		    x = sidebar_width,
+		    y = 0,
+		    width = screen_width - (sidebar_width * 2),
+		    height = screen_height * 0.30,
+		}
+
+		rl.BeginDrawing()
+		rl.ClearBackground(rl.BLACK)
+
+		// TODO: move this out / make better
+		// --------------------------------------
+		// CPU cycles
+		for _ in 0..<12 {
+			m.handle_input(s)
+			m.cycle(s)
+		}
+		// --------------------------------------
+
+		// run each gui "component"
+		gui_screen(display_rect, s)
+
+		rl.EndDrawing()
+	}
+
+	rl.CloseAudioDevice()
+	rl.CloseWindow()
+}
\ No newline at end of file
diff --git a/src/gui/screen.odin b/src/gui/screen.odin
new file mode 100644
index 0000000..adc815c
--- /dev/null
+++ b/src/gui/screen.odin
@@ -0,0 +1,77 @@
+package gui
+
+import m "../machine"
+import rl "vendor:raylib"
+
+control_bar_height :: f32(20.0)
+
+gui_screen :: proc(window_rect: rl.Rectangle, s: ^m.System) {
+	control_bar_rect := rl.Rectangle{
+		x = window_rect.x,
+		y = window_rect.y,
+		width = window_rect.width,
+		height = control_bar_height
+	}
+
+	content_rect := rl.Rectangle{
+		x = window_rect.x,
+		y = window_rect.y + control_bar_height,
+		width = window_rect.width,
+		height = window_rect.height - control_bar_height
+	}
+
+    chip8_aspect := f32(64.0 / 32.0)
+    available_aspect := content_rect.width / content_rect.height
+
+    screen_rect := content_rect
+
+    if available_aspect > chip8_aspect {
+       // Content area is too wide
+       screen_rect.height = content_rect.height
+       screen_rect.width = content_rect.height * chip8_aspect
+
+       screen_rect.x = content_rect.x + (content_rect.width - screen_rect.width) / 2
+       screen_rect.y = content_rect.y
+   } else {
+       // Content area is too tall
+       screen_rect.width = content_rect.width
+       screen_rect.height = content_rect.width / chip8_aspect
+
+       screen_rect.x = content_rect.x
+       screen_rect.y = content_rect.y + (content_rect.height - screen_rect.height) / 2
+    }
+
+    pixel_size := min(int(screen_rect.width / 64), int(screen_rect.height / 32))
+	pixel_size = max(pixel_size, 1)
+
+	actual_width := pixel_size * 64
+	actual_height := pixel_size * 32
+
+	display_x := i32(int(screen_rect.x) + (int(screen_rect.width) - actual_width) / 2)
+	display_y := i32(int(screen_rect.y) + (int(screen_rect.height) - actual_height) / 2)
+
+	// Debug borders
+	rl.DrawRectangleLinesEx(window_rect, 1, rl.DARKGRAY)
+	rl.DrawRectangleLinesEx(control_bar_rect, 1, rl.GREEN)
+	rl.DrawRectangleLinesEx(screen_rect, 2, rl.WHITE)
+
+	render_display(&s.display, display_x, display_y, i32(pixel_size))
+}
+
+@(private = "file")
+render_display :: proc(display_buffer: ^[32][64]u8, offset_x, offset_y, scale: i32) {
+	// Fill display area with black background
+	rl.DrawRectangle(offset_x, offset_y, 64 * scale, 32 * scale, rl.BLACK)
+	for y in 0..<len(display_buffer) {
+		for x in 0..<len(display_buffer[0]) {
+			if display_buffer[y][x] == 0x01 {
+				rl.DrawRectangle(
+					i32(x) * scale + offset_x,
+					i32(y) * scale + offset_y,
+					scale, scale,
+					rl.WHITE,
+				)
+			}
+		}
+	}
+}
diff --git a/src/main.odin b/src/main.odin
index 880e8e9..1cff41a 100644
--- a/src/main.odin
+++ b/src/main.odin
@@ -4,6 +4,7 @@ import "core:log"
 import "core:mem"
 
 import chip "machine"
+import gui "gui"
 
 DEV :: #config(DEV, false)
 
@@ -22,17 +23,17 @@ main :: proc() {
 	// Init the Chip 8 "cpu"
 	system := chip.init()
 
+	// TODO: move this into a gui component
 	// load rom, hardcoded for now, will eventually be cli or gui
-	// err := chip.load_rom(&system, "./test_roms/2-ibm-logo.ch8")
-	// err := chip.load_rom(&system, "./test_roms/1-chip8-logo.ch8")
-	// err := chip.load_rom(&system, "./test_roms/4-flags.ch8")
-	err := chip.load_rom(&system, "./test_roms/6-keypad.ch8")
+	err := chip.load_rom(&system, "./test_roms/7-beep.ch8")
 	if err != nil {
 		panic("failed to load rom!")
 	}
 
-	// start the cycle
-	chip.run_system(&system)
+	// gui will init the layout etc, it will require reference to
+	// the system as it will use its display buffer etc
+	// NOTE: may just need a few fields rather than whole struct check later
+	gui.init_gui(&system)
 
 	when DEV {
 		if len(track.allocation_map) > 0 {