From 1a57ab1e2687a5c3508a7c95a6582363ca5b3e14 Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Sun, 8 May 2022 20:47:58 -0700
Subject: [PATCH] Cleaned the interrupt code a bit

---
 src/interrupts.c | 20 ++++++++++++++++++++
 src/interrupts.h | 14 ++++++++++++++
 src/main.c       | 18 +++---------------
 src/main.h       |  4 +---
 4 files changed, 38 insertions(+), 18 deletions(-)
 create mode 100644 src/interrupts.c
 create mode 100644 src/interrupts.h

diff --git a/src/interrupts.c b/src/interrupts.c
new file mode 100644
index 0000000..b23626f
--- /dev/null
+++ b/src/interrupts.c
@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) 2022 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "interrupts.h"
+
+void interruptOnScanline() {
+  if(LYC_REG == 0) {
+    LCDC_REG |= LCDCF_BG8000;
+    if((TEXTBOX_STATE & TEXTBOX_STATE_VISIBLE) != 0) {
+      LYC_REG = INTERRUPT_TEXTBOX_VRAM;
+    }
+  } else if(LYC_REG == INTERRUPT_TEXTBOX_VRAM) {
+    LCDC_REG &= ~LCDCF_BG8000;
+    LYC_REG = 0;
+  }
+}
\ No newline at end of file
diff --git a/src/interrupts.h b/src/interrupts.h
new file mode 100644
index 0000000..0c589f2
--- /dev/null
+++ b/src/interrupts.h
@@ -0,0 +1,14 @@
+/**
+ * Copyright (c) 2022 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "libs.h"
+#include "conversation/textbox.h"
+
+#define INTERRUPT_TEXTBOX_VRAM ((TEXTBOX_WIN_Y * TILE_HEIGHT) - 1)
+
+void interruptOnScanline();
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 023a1e9..22ae750 100644
--- a/src/main.c
+++ b/src/main.c
@@ -7,18 +7,6 @@
 
 #include "main.h"
 
-#define TEXTBOX_INTERRUPT_Y ((TEXTBOX_WIN_Y * TILE_HEIGHT) - 1)
-
-// TODO: cleanup
-void scanline_isr() {
-  if(LYC_REG == 0) {
-    LYC_REG = TEXTBOX_INTERRUPT_Y;
-    LCDC_REG |= LCDCF_BG8000;
-  } else if(LYC_REG == TEXTBOX_INTERRUPT_Y) {
-    LYC_REG = 0;
-    LCDC_REG &= ~LCDCF_BG8000;
-  }
-}
 
 void main() {
   int16_t j;
@@ -27,14 +15,13 @@ void main() {
   // Set up the GAMEBOY's registers.
   disable_interrupts();
 
-  // Create a critical section
+  // Create a critical section for some video stuff
   CRITICAL {
     DISPLAY_OFF;
     LCDC_REG = LCDCF_OFF | LCDCF_BG8000 | LCDCF_BG9800 | LCDCF_BGON;
     STAT_REG |= STATF_LYC;
     LYC_REG = 0;
-
-    add_LCD(scanline_isr);
+    add_LCD(interruptOnScanline);
   }
   set_interrupts(VBL_IFLAG | LCD_IFLAG);
 
@@ -98,5 +85,6 @@ void main() {
     // Update conversation fade effect
     conversationFadeUpdate();
     // mainDebugDraw();
+    LCDC_REG |= LCDCF_BG8000;
   }
 }
\ No newline at end of file
diff --git a/src/main.h b/src/main.h
index 80b6fd8..2a10cd4 100644
--- a/src/main.h
+++ b/src/main.h
@@ -9,9 +9,7 @@
 
 #include "libs.h"
 #include "time.h"
-
 #include "SM.h"
-
 #include "poker/poker.h"
 #include "poker/card.h"
 #include "conversation/fade.h"
@@ -19,7 +17,7 @@
 #include "conversation/queue.h"
 #include "conversation/textbox.h"
 #include "conversation/questionbox.h"
-
+#include "interrupts.h"
 #include "sprites/spritecards.h"
 
 #define GB_BACKGROUND_COLUMNS 0x20