From c3367cdf3e35f92fbc2d5f7d9f28a25367cb8a48 Mon Sep 17 00:00:00 2001
From: Jason Hilder <jhilder95@gmail.com>
Date: Sat, 13 Jun 2026 09:29:53 +0200
Subject: [PATCH] Added left panel rom loader.

Left panel has tinyfieldialogs to open a file picker, so you can swap
out roms, required a reset machine function aswell.
---
 src/machine/cpu.odin          |  2 +-
 src/machine/machine.odin      | 15 ++++++++++++
 src/main.odin                 |  7 ------
 src/simulator/left_panel.odin | 45 ++++++++++++++++++++++++++---------
 4 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/src/machine/cpu.odin b/src/machine/cpu.odin
index e371a2d..ea1c5c8 100644
--- a/src/machine/cpu.odin
+++ b/src/machine/cpu.odin
@@ -333,4 +333,4 @@ op_mem_get :: proc(s: ^System, vx_idx: u16) {
 	for loop_idx in 0..=vx_idx {
 		s.v[loop_idx] = s.memory[s.i + loop_idx]
 	}
-}
\ No newline at end of file
+}
diff --git a/src/machine/machine.odin b/src/machine/machine.odin
index af72f61..b342400 100644
--- a/src/machine/machine.odin
+++ b/src/machine/machine.odin
@@ -68,3 +68,18 @@ run_machine :: proc(s: ^System, cycles: int) {
 		cycle(s)
 	}
 }
+
+new_machine :: proc() -> System {
+    s: System
+    s.pc = 0x200
+    s.current_key = -1
+	// load fonts into the memory
+	for v, i in FONT_SET {
+		s.memory[i] = v
+	}
+    return s
+}
+
+reset_machine :: proc(s: ^System) {
+    s^ = new_machine()
+}
diff --git a/src/main.odin b/src/main.odin
index 7e4bdc7..bcca549 100644
--- a/src/main.odin
+++ b/src/main.odin
@@ -23,13 +23,6 @@ main :: proc() {
 	// Init the emu 8 "cpu"
 	system := emu.init()
 
-	// @TODO: move this into a gui component
-	// load rom, hardcoded for now, will eventually be cli or gui
-	err := emu.load_rom(&system, "./test_roms/7-beep.ch8")
-	if err != nil {
-		panic("failed to load rom!")
-	}
-
 	// Initilize sim, gui etc
 	sim.run_simulator(&system)
 
diff --git a/src/simulator/left_panel.odin b/src/simulator/left_panel.odin
index 26abbb2..c6ba6e5 100644
--- a/src/simulator/left_panel.odin
+++ b/src/simulator/left_panel.odin
@@ -4,6 +4,9 @@ import "core:log"
 import "core:strings"
 import rl "vendor:raylib"
 
+import emu "../machine"
+import tfd "../../external/tinyfiledialogs"
+
 gui_left_panel :: proc(rect: rl.Rectangle, sim: ^Simulator) {
 	// ── Top panel and components ──
 	top_panel := rl.Rectangle {
@@ -16,13 +19,12 @@ gui_left_panel :: proc(rect: rl.Rectangle, sim: ^Simulator) {
 
 	// Dropzone/file loader
 	file_loader_rect := rl.Rectangle {
-		top_panel.x + PANEL_PADDING,
-		top_panel.y + PANEL_HEADER,
-		top_panel.width - PANEL_PADDING * 2,
+		top_panel.x,
+		top_panel.y,
+		top_panel.width,
 		(top_panel.height / 3) - PANEL_HEADER - PANEL_PADDING * 2,
 	}
-	rl.GuiPanel(file_loader_rect, "Rom / File")
-	gui_file_loader(file_loader_rect)
+	gui_file_loader(file_loader_rect, sim)
 
 	// ── Bottom panel and components ──
 	bottom_panel := rl.Rectangle {
@@ -35,7 +37,9 @@ gui_left_panel :: proc(rect: rl.Rectangle, sim: ^Simulator) {
 	gui_key_pad(bottom_panel, sim.machine.keypad, sim.font)
 }
 
-gui_file_loader :: proc(rect: rl.Rectangle) {
+gui_file_loader :: proc(rect: rl.Rectangle, sim: ^Simulator) {
+	rl.GuiPanel(rect, "Rom / File")
+
 	// drop-zone occupies the panel's content area, minus space for the button
 	drop_zone := rl.Rectangle {
 		rect.x + PANEL_PADDING,
@@ -47,10 +51,10 @@ gui_file_loader :: proc(rect: rl.Rectangle) {
 
 	// centered drop-zone text
 	text: cstring = "Drop a CHIP-8 ROM here"
-	text_width := rl.MeasureText(text, DROP_FONT_SIZE)
+	text_width := rl.MeasureText(text, BIG_FONT_SIZE)
 	text_x := drop_zone.x + (drop_zone.width - f32(text_width)) / 2
-	text_y := drop_zone.y + (drop_zone.height - f32(DROP_FONT_SIZE)) / 2
-	rl.DrawText(text, i32(text_x), i32(text_y), DROP_FONT_SIZE, rl.GRAY)
+	text_y := drop_zone.y + (drop_zone.height - f32(BIG_FONT_SIZE)) / 2
+	rl.DrawTextEx(sim.font, text, {text_x, text_y}, BIG_FONT_SIZE, 1, rl.WHITE)
 
 	// open rom button below drop-zone
 	btn_rect := rl.Rectangle {
@@ -61,7 +65,23 @@ gui_file_loader :: proc(rect: rl.Rectangle) {
 	}
 
 	if rl.GuiButton(btn_rect, "Open ROM") {
-		// @TODO: get tinyfiledialog working here
+		ret := tfd.openFileDialog("Open File Dialog", nil, 0, nil, nil, 0,)
+		rom_path := string(ret)
+		if rom_path == "" do return
+
+		// reset machine state
+		emu.reset_machine(sim.machine)
+
+		// load new rom
+		err := emu.load_rom(sim.machine, rom_path)
+		if err != nil {
+			// @TODO: update status bar here
+			panic("failed to load rom!")
+		}
+
+		sim.rom_loaded = true
+		sim.running = true
+		sim.paused = false
 	}
 
 	// Handle file drop
@@ -96,6 +116,7 @@ gui_key_pad :: proc(rect: rl.Rectangle, display: [16]bool, font: rl.Font) {
 		label: string,
 		index: int,
 	}
+
 	keys := [16]Key {
 		{"1", 1}, {"2", 2}, {"3", 3}, {"C", 12},
 		{"4", 4}, {"5", 5}, {"6", 6}, {"D", 13},
@@ -122,7 +143,9 @@ gui_key_pad :: proc(rect: rl.Rectangle, display: [16]bool, font: rl.Font) {
 		if display[val.index] { rl.DrawRectangleRec(irect, rl.BLACK) }
 
 		rl.DrawRectangleLinesEx(irect, 1, rl.GRAY)
-		rl.DrawTextEx( font, str,
+		rl.DrawTextEx(
+			font,
+			str,
 			rl.Vector2{irect.x + btn_width / 2, irect.y + btn_height / 2},
 			KEYPAD_FONT_SIZE,
 			1,