From f199eae0154f354c37750c8cd3037f94dbfe70db Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <petermikkelsen10@gmail.com>
Date: Sat, 26 Jul 2025 16:03:00 +0200
Subject: Initial commit

---
 src/screen.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 src/screen.c

(limited to 'src/screen.c')

diff --git a/src/screen.c b/src/screen.c
new file mode 100644
index 0000000..1ce4192
--- /dev/null
+++ b/src/screen.c
@@ -0,0 +1,116 @@
+#include "aplos.h"
+
+#define FOREGROUND 0x442A13
+#define BACKGROUND 0xE3DFD7
+
+static struct framebuffer *fb;
+static volatile uint32_t *fb_mem;
+
+static uint32_t row;
+static uint32_t col;
+
+static void screen_clear(void);
+static int print_fmt(char8_t *, va_list);
+
+void
+screen_init(struct framebuffer *framebuffer)
+{
+	fb = framebuffer;
+	fb_mem = fb->addr;
+	screen_clear();
+
+	font_init();
+}
+
+void
+screen_draw_pixel(uint32_t x, uint32_t y, uint32_t c)
+{
+	fb_mem[x + y * (fb->pitch/4)] = c;
+}
+
+void
+print(char8_t *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+
+	int n;
+	for(char8_t *p = fmt; *p; p += utf8_char_length(p)){
+		switch(*p){
+		default:
+print_char:
+			font_draw(p, row, col, BACKGROUND, FOREGROUND);
+			col++;
+			break;
+		case '\n':
+			row++;
+			col = 0;
+			break;
+		case '%':
+			n = print_fmt(p, args);
+			if(n == 0)
+				goto print_char;
+			while(n-- > 1)
+				p += utf8_char_length(p);
+			break;
+		}
+	}
+	va_end(args);
+}
+
+static void
+screen_clear(void)
+{
+	for(uint64_t y = 0; y < fb->height; y++){
+		for(uint64_t x = 0; x < fb->width; x++){
+			fb_mem[x + y * (fb->pitch/4)] = BACKGROUND;
+		}
+	}
+}
+
+static int
+print_fmt(char8_t *fmt, va_list args)
+{
+	char8_t digits[] = u8"0123456789ABCDEF";
+	char8_t *prefixes[17] = {0};
+	char8_t buf[65];
+	char8_t *p = &buf[nelem(buf)-1];
+
+	prefixes[2] = u8"0b";
+	prefixes[8] = u8"0o";
+	prefixes[16] = u8"0x";
+
+	*p = 0;
+
+#define UINT(spec, n, base, min, type) 		\
+	if(utf8_cmp_n(fmt, spec, 2+n) == 0){	\
+		type v = va_arg(args, type);	\
+		int w = min;			\
+		do{				\
+			p--;			\
+			*p = digits[v%base];	\
+			v = v / base;		\
+			if(w)			\
+				w--;		\
+		}while(v || w);			\
+		if(prefixes[base])		\
+			print(prefixes[base]);	\
+		print(p);			\
+		return 2+n;			\
+	}
+
+#define UINTS(bits, n, type)		\
+	UINT(u8"%b" #bits, n, 2, 0, type)	\
+	UINT(u8"%o" #bits, n, 8, 0, type)	\
+	UINT(u8"%u" #bits, n, 10, 0, type)	\
+	UINT(u8"%x" #bits, n, 16, 0, type)	\
+
+	UINTS(64, 2, uint64_t);
+	UINTS(32, 2, uint32_t);
+	UINTS(16, 2, int);
+	UINTS(8,  1, int);
+
+	UINT(u8"%p", 0, 16, 16, uintptr_t);
+
+	return 0;
+}
-- 
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