From 98ea7e6280aa7656e05334ea91406147a4ee4a36 Mon Sep 17 00:00:00 2001
From: Tom-on64 <kubecekt@gmail.com>
Date: Mon, 29 Apr 2024 19:38:51 +0200
Subject: [PATCH] Made screen.h more generic, instead of just assuming
 1920x1080 32bpp mode

---
 include/screen.h | 41 +++++++++++++++++++++++++++--------------
 src/kernel.c     |  2 +-
 todo.txt         |  7 +++++++
 3 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/include/screen.h b/include/screen.h
index ac1b93a..1832719 100644
--- a/include/screen.h
+++ b/include/screen.h
@@ -6,6 +6,8 @@
 #define MODE_INFO_BLOCK 0x5000
 #define BG_COLOR 0xff010b17
 #define FG_COLOR 0xffebddf4
+#define CHAR_WIDTH 8
+#define CHAR_HEIGHT 16
 
 typedef struct modeInfoBlock_s {
     // Required by all VBE revisions
@@ -74,23 +76,29 @@ static char* font = (char*)0x6000;
 static struct cursor_s cursor = { 0, 0 };
 static modeInfoBlock_t* gfxMode = (modeInfoBlock_t*)MODE_INFO_BLOCK;
 
-// TODO: Probably make the font bigger in a better way, but this works for now
+uint32_t bgColor = BG_COLOR;
+uint32_t fgColor = FG_COLOR;
+
 void putcAt(unsigned char c, uint32_t x, uint32_t y) {
-    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
-    uint32_t offset = (gfxMode->xRes * y * 16 + x * 8) * 2;
+    uint8_t* vidmem = (uint8_t*)gfxMode->physicalBasePtr;
+    uint8_t bytesPerPx = (gfxMode->bpp+1) / 8;
+    uint32_t offset = (gfxMode->xRes * y * CHAR_HEIGHT + x * CHAR_WIDTH) * bytesPerPx;
 
     char* bitmap = &font[((c % 128) - 1) * 16];
-    for (uint8_t i = 0; i < 32; i++) { // Rows (16*2 since we draw font 2x larger)
-        char bitmapRow = bitmap[i/2]; // Idk if this should work, because i'm scared of division
+    for (uint8_t i = 0; i < CHAR_HEIGHT; i++) { // Rows
+        char bitmapRow = bitmap[i]; 
         
-        for (uint8_t j = 0; j < 16; j++) { // Cols (8*2 same as rows)
-            vidmem[offset + j] = (bitmapRow & 0x80) ? FG_COLOR : BG_COLOR;
-            if (j % 2) {
+        for (uint8_t j = 0; j < CHAR_WIDTH * bytesPerPx; ++j) { // Cols 
+            uint32_t color = (bitmapRow & 0x80) ? fgColor : bgColor;
+            uint8_t byte = j % bytesPerPx;
+            vidmem[offset + j] = (uint8_t)(color >> (8 * byte));
+
+            if (byte == bytesPerPx - 1) {
                 bitmapRow = bitmapRow << 1;
             }
-        } 
+        }
 
-        offset += gfxMode->xRes;
+        offset += gfxMode->linearBytesPerScanline; // gfxMode->xRes * bytesPerPx
     }
 }
 
@@ -122,13 +130,18 @@ void print(const char* str) {
     }
 }
 
+// TODO: Optimize this, it is VERY slow
 void clear() {
-    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
+    uint8_t* vidmem = (uint8_t*)gfxMode->physicalBasePtr;
+    uint8_t bytesPerPx = (gfxMode->bpp+1) / 8;
 
     size_t i = 0;
-    while (i < gfxMode->xRes * gfxMode->yRes) {
-        vidmem[i] = BG_COLOR; // #1f2937
-        i++;
+    uint8_t j = 0;
+    while (i < gfxMode->xRes * gfxMode->yRes) { // Loop through all pixels
+        vidmem[i * bytesPerPx + j] = (uint8_t)(bgColor >> (j*8));
+
+        j = (j + 1) % bytesPerPx;
+        if (!j) { i++; }
     }
 
     cursor.x = 0;
diff --git a/src/kernel.c b/src/kernel.c
index cd459c7..5dfc5df 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -54,7 +54,7 @@ void main() {
     print("kern.\n\n");
 
     diskRead(5, 1, filetable); // Read the filetable and store it in memory
-    
+
     // Run Interactive Shell Program
     // TODO: Make it in another file
     while (1) {
diff --git a/todo.txt b/todo.txt
index 6324ad6..b9e3fb2 100644
--- a/todo.txt
+++ b/todo.txt
@@ -16,6 +16,8 @@
     - [ ] Variable text size :)
     - [ ] Make output overflow go to next line
     - [ ] More fonts
+    - [x] Generic screen.h stuff (don't assume 1920x1080 32bpp)
+    - [ ] 
 - [x] Graphics
     - [?] Enter/exit a "graphics" mode (idk if we need this)
     - [x] Pixel drawing
@@ -68,6 +70,7 @@
     - [ ] Malloc()
     - [ ] Free()
 - [ ] Shell
+    - [ ] Separate file/program
     - [ ] ';' separated commands
     - [ ] I/O Redirection with '<' '>'
     - [ ] Commands
@@ -111,4 +114,8 @@
     - [ ] Standard libs
 - [ ] Finish all todos
 - [ ] Refactoring!!!
+- [ ] Can it run DOOM?
+- [ ] Games
+    - [ ] Minesweeper
+    - [ ] Solitaire