From 9fec34806e67bb631bd5c0325742b126ee8c855d Mon Sep 17 00:00:00 2001
From: Benji Dial <benji@benjidial.net>
Date: Thu, 25 Dec 2025 16:51:25 -0500
Subject: [PATCH] better mouse demo

---
 kernel/src/ps2.c | 74 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 54 insertions(+), 20 deletions(-)

diff --git a/kernel/src/ps2.c b/kernel/src/ps2.c
index 1c54e68..6da5884 100644
--- a/kernel/src/ps2.c
+++ b/kernel/src/ps2.c
@@ -16,40 +16,74 @@
  */
 
 #include <framebuffer.h>
+#include <panic.h>
 #include <ps2.h>
 
 //defined in ps2.asm
 //returns -1 if no byte available
 int read_ps2_byte();
 
-static uint32_t color = 1;
+static void process_keyboard_byte(uint8_t byte) {
+  (void)byte;
+  //TODO
+}
 
-static void change_color() {
+static uint8_t mouse_packet[3];
+static int mouse_packet_length = 0;
 
-  color ^= color << 13;
-  color ^= color >> 17;
-  color ^= color << 5;
+static int total_x = 0;
+static int total_y = 0;
 
-  for (int y = 0; y < fb_height; ++y)
-    for (int x = 0; x < fb_width; ++x)
-      *(uint32_t *)&fb_base[y * fb_pitch + x * 4] = color & 0x00ffffff;
+static void process_mouse_byte(uint8_t byte) {
+
+  mouse_packet[mouse_packet_length] = byte;
+  if (mouse_packet_length < 2) {
+    ++mouse_packet_length;
+    return;
+  }
+  mouse_packet_length = 0;
+
+  int x = mouse_packet[1];
+  if (mouse_packet[0] & 0x10)
+    x -= 256;
+
+  int y = mouse_packet[2];
+  if (mouse_packet[0] & 0x20)
+    y -= 256;
+
+  total_x += x;
+  total_y -= y;
+
+  if (total_x < 0)
+    total_x = 0;
+  if (total_x >= fb_width)
+    total_x = fb_width - 1;
+
+  if (total_y < 0)
+    total_y = 0;
+  if (total_y >= fb_height)
+    total_y = fb_height - 1;
+
+  fb_base[total_y * fb_pitch + total_x * 4] = 0xff;
+  fb_base[total_y * fb_pitch + total_x * 4 + 1] = 0xff;
+  fb_base[total_y * fb_pitch + total_x * 4 + 2] = 0xff;
 
 }
 
 void on_keyboard_irq() {
-
-  while (read_ps2_byte() != -1)
-    ;
-
-  change_color();
-
+  while (1) {
+    int byte = read_ps2_byte();
+    if (byte == -1)
+      return;
+    process_keyboard_byte(byte);
+  }
 }
 
 void on_mouse_irq() {
-
-  while (read_ps2_byte() != -1)
-    ;
-
-  change_color();
-
+  while (1) {
+    int byte = read_ps2_byte();
+    if (byte == -1)
+      return;
+    process_mouse_byte(byte);
+  }
 }