From d0c778f397df8fa6f813fb364525840fe21af767 Mon Sep 17 00:00:00 2001
From: maelstrom <maelstrom@noreply.git.maelstrom.dev>
Date: Thu, 25 Jul 2024 21:20:57 +0300
Subject: [PATCH] We uhh.... ran out of space

---
 boot.asm     |  2 +-
 gfx/cvbmp.py |  6 +++---
 gfx_util.asm | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 main.asm     | 19 +++++++++----------
 4 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/boot.asm b/boot.asm
index 126351c..0a2e867 100644
--- a/boot.asm
+++ b/boot.asm
@@ -7,7 +7,7 @@ OS_SEGMENT equ 0x100
 boot:
     ; Load from disk
     mov ah, 0x02 ; read
-    mov al, 0x01 ; No of sectors (1)
+    mov al, 0x02 ; No of sectors (1)
     mov cl, 0x02 ; Sector start (1 = boot sector, 2 = OS)
     mov ch, 0x00 ; Cylinder 0
     mov dh, 0x00 ; Head 0
diff --git a/gfx/cvbmp.py b/gfx/cvbmp.py
index c0c4031..1b51acb 100644
--- a/gfx/cvbmp.py
+++ b/gfx/cvbmp.py
@@ -5,8 +5,8 @@ pixels = list(im.getdata())
 w, h = im.size
 
 with open('gfxd_cursor.asm', 'w') as f:
-    f.write(f'gfxd_cursor_dim: db {w} db {h}\n')
-    f.write('gfxd_cursor: ')
+    f.write(f'gfxd_cursor_dim: db {w}, {h}\n')
+    f.write('gfxd_cursor: db ')
 
     for px in pixels:
         if px == (255, 255, 255, 255):
@@ -15,4 +15,4 @@ with open('gfxd_cursor.asm', 'w') as f:
             c = '0x00'
         else:
             c = '0xFF'
-        f.write(f'db {c} ')
\ No newline at end of file
+        f.write(f'{c}, ')
\ No newline at end of file
diff --git a/gfx_util.asm b/gfx_util.asm
index ee57e25..87475cb 100644
--- a/gfx_util.asm
+++ b/gfx_util.asm
@@ -1,5 +1,14 @@
+; Constants
 VMEM equ 0xA000
 
+; Initializes 320x200 8-bit/256-color (13h) video graphics mode
+gfx_init_vga13:
+    push ax
+    mov ax, 0x0013
+    int 0x10
+    pop ax
+    ret
+
 ; di = y*32+x
 ; ax = width
 ; bl = height
@@ -66,5 +75,47 @@ gfx_rect:
 
     call _gfx_rect0
 
+    popa
+    ret
+
+
+; di = y*32+x
+; si = source color data
+; ax = width
+; bl = height
+
+; ax/bl = 0 is undefined behavior. Don't do it.
+; (To be clear, in the current implementation it just halts)
+
+_gfx_blit0:
+    pusha
+
+    push VMEM
+    pop es
+
+    mov dl, 0 ; row counter
+
+    .row:
+        add dl, 1
+
+        mov cx, 0 ; col counter
+
+        .col:
+            add cx, 1
+
+            mov dh, [si]
+            mov [es:di], dh
+            add di, 1
+            add si, 1
+
+            cmp cx, ax
+            jnz .col
+        
+        sub di, ax ; di - width + 320. == x=x1; y++
+        add di, 320
+
+        cmp dl, bl
+        jnz .row
+
     popa
     ret
\ No newline at end of file
diff --git a/main.asm b/main.asm
index 6d7d770..46d3cb2 100644
--- a/main.asm
+++ b/main.asm
@@ -18,16 +18,13 @@ section KERNEL follows=BOOTSECTOR vstart=1000h
 %endmacro
 
 main:
-    mov ax, 0x0013
-    int 0x10
+    call gfx_init_vga13
 
-    mov cx, 50 ; x
-    mov al, 50 ; y
-    mov dx, 100 ; w
-    mov bl, 100 ; h
-    mov bh, 0x01 ; color = Dark blue
-
-    call gfx_rect
+    mov di, 0
+    mov si, gfxd_cursor
+    mov ax, 11
+    mov bl, 18
+    call _gfx_blit0
 
 jmp $ ; Halt
     
@@ -38,4 +35,6 @@ jmp $ ; Halt
     
 ; Data
 HELLO_WORLD:
-    db 'Hello, world! :D', 0
\ No newline at end of file
+    db 'Hello, world! :D', 0
+
+%include "gfx/gfxd_cursor.asm"
\ No newline at end of file