Folder restructuration

src/io/term/term.c

@@ -0,0 +1,143 @@
+// Terminal output
+
+#include <limine.h>
+#include <stddef.h>
+#include <kernel.h>
+#include "term.h"
+
+extern struct limine_framebuffer* framebuffer;
+
+// Importing the PSF object file
+extern unsigned char _binary_zap_light16_psf_start[];
+extern unsigned char _binary_zap_light16_psf_end[];
+
+PSF1_Header* font = (PSF1_Header*)_binary_zap_light16_psf_start;
+uint8_t* glyphs = _binary_zap_light16_psf_start + sizeof(PSF1_Header);
+
+#define FONT_WIDTH 8
+#define FONT_HEIGHT font->characterSize
+
+// Character cursor
+typedef struct
+{
+	unsigned int x;
+	unsigned int y;
+} Cursor;
+
+Cursor cursor = {0};
+
+unsigned char* fb;
+
+int term_init()
+{
+	// Get framebuffer address from Limine struct
+	
+	if (framebuffer)
+	{
+		fb = framebuffer->address;
+		return 0;
+	}
+	return -ENOMEM;
+}
+
+// These are marked "static" because we don't wanna expose them all around
+// AKA they should just be seen here (kind of like private functions in cpp)
+static void putpixel(int x, int y, int color)
+{
+	// Depth isn't part of limine_framebuffer attributes so it will be 4
+	unsigned pos = x*4 + y*framebuffer->pitch;
+	fb[pos] = color & 255; // blue channel
+	fb[pos+1] = (color >> 8) & 255; // green
+	fb[pos+2] = (color >> 16) & 255; // blue
+}
+
+static void draw_char(char c, int px, int py, int fg, int bg)
+{
+	uint8_t* glyph = glyphs + ((unsigned char)c * FONT_HEIGHT);
+
+	for (size_t y=0; y<FONT_HEIGHT; y++)
+	{
+		uint8_t row = glyph[y];
+		for (size_t x=0; x<8; x++)
+		{
+			int color = (row & (0x80 >> x)) ? fg : bg;
+			putpixel(px+x, py+y, color);
+		}
+	}
+}
+
+static void erase_char(int px, int py)
+{
+	for (size_t y=0; y<FONT_HEIGHT; y++)
+	{
+		for (size_t x=0; x<8; x++)
+		{
+			// Black
+			putpixel(px+x, py+y, 0);
+		}
+	}
+}
+
+void putchar(char c)
+{
+	if (c == '\n')
+	{
+		cursor.x = 0;
+		cursor.y++;
+		return;
+	}
+
+	// TODO: Improperly handled.
+	// When we're on an empty line it should get to the upper line's last character
+	// NOT just the last position possible; we would need to track the last line's character amount for that
+	if (c == '\b')
+	{
+		if (cursor.x == 0 && cursor.y == 0)
+		{
+			// Top-left corner
+			return;
+		}
+
+		if (cursor.x == 0)
+		{
+			cursor.y--;
+			cursor.x = (framebuffer->width / FONT_WIDTH) -1; // here
+		}
+		else {
+			cursor.x--;
+		}
+
+		int px = cursor.x * FONT_WIDTH;
+		int py = cursor.y * FONT_HEIGHT;
+		erase_char(px, py);
+		return;
+	}
+
+	if ((cursor.x+1)*FONT_WIDTH >= framebuffer->width)
+	{
+		cursor.x = 0;
+		cursor.y++;
+	}
+
+	int px = cursor.x * FONT_WIDTH;
+	int py = cursor.y * FONT_HEIGHT;
+	draw_char(c, px, py, WHITE, BLACK);
+	cursor.x++;
+}
+
+// Overhead that could be avoided, right? (for printf)
+void _putchar(char character)
+{
+	putchar(character);
+}
+
+// Debug-printing
+void kputs(const char* str)
+{
+	unsigned int i=0;
+	while (str[i] != 0)
+	{
+		putchar(str[i]);
+		i++;
+	}
+}