4 files changed, 204 insertions, 0 deletions
diff --git a/src/cmd/vterm/draw.c b/src/cmd/vterm/draw.c
new file mode 100644
index 0000000..ee36a0f
--- /dev/null
+++ b/src/cmd/vterm/draw.c
@@ -0,0 +1,17 @@
+#include "vterm.h"
+#include <camellia/execbuf.h>
+#include <camellia/syscalls.h>
+#include <string.h>
+
+struct framebuf fb;
+struct rect dirty;
+
+void scroll(void) {
+	size_t row_len = fb.pitch * font.h;
+	memmove(fb.b, fb.b + row_len, fb.len - row_len);
+	memset(fb.b + fb.len - row_len, 0, row_len);
+	cursor.y--;
+
+	dirty.x1 =  0; dirty.y1 =  0;
+	dirty.x2 = ~0; dirty.y2 = ~0;
+}
diff --git a/src/cmd/vterm/font.c b/src/cmd/vterm/font.c
new file mode 100644
index 0000000..777b094
--- /dev/null
+++ b/src/cmd/vterm/font.c
@@ -0,0 +1,76 @@
+#include "vterm.h"
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct psf2 font;
+void *font_data;
+
+void font_load(const char *path) {
+	FILE *f = fopen(path, "r");
+	if (!f) {
+		err(1, "couldn't open font \"%s\"", path);
+	}
+
+	void *buf;
+	long buflen;
+
+	fseek(f, 0, SEEK_END);
+	buflen = ftell(f);
+	if (buflen < 0) {
+		errx(1, "can't get the size of \"%s\"", path);
+	}
+
+	buf = malloc(buflen);
+	if (!buf) {
+		err(1, "out of memory");
+	}
+
+	fseek(f, 0, SEEK_SET);
+	fread(buf, 1, buflen, f);
+	if (ferror(f)) {
+		err(1, "error reading font");
+	}
+	fclose(f);
+
+	if (!memcmp(buf, "\x72\xb5\x4a\x86", 4)) {
+		memcpy(&font, buf, sizeof font);
+		font_data = buf + font.glyph_offset;
+	} else if (!memcmp(buf, "\x36\x04", 2)) {
+		struct psf1 *hdr = buf;
+		font = (struct psf2){
+			.glyph_amt = 256,
+			.glyph_size = hdr->h,
+			.h = hdr->h,
+			.w = 8,
+		};
+		font_data = buf + 4;
+	} else {
+		errx(1, "invalid psf header");
+	}
+}
+
+void font_blit(uint32_t glyph, int x, int y) {
+	if (glyph >= font.glyph_amt) glyph = 0;
+	if (x < 0 || (x+1) * font.w >= fb.width ||
+		y < 0 || (y+1) * font.h >= fb.height)
+	{
+		return;
+	}
+
+	dirty_mark(&dirty, x * font.w, y * font.h);
+	dirty_mark(&dirty, (x+1) * font.w - 1, (y+1) * font.h - 1);
+
+	char *bitmap = font_data + font.glyph_size * glyph;
+	for (size_t i = 0; i < font.w; i++) {
+		for (size_t j = 0; j < font.h; j++) {
+			size_t idx = j * font.w + i;
+			char byte = bitmap[idx / 8];
+			byte >>= (7-(idx&7));
+			byte &= 1;
+			*((uint32_t*)&fb.b[fb.pitch * (y * font.h + j) + 4 * (x * font.w + i)]) = byte * 0xB0B0B0;
+		}
+	}
+	return;
+}
diff --git a/src/cmd/vterm/vterm.c b/src/cmd/vterm/vterm.c
new file mode 100644
index 0000000..f365f6b
--- /dev/null
+++ b/src/cmd/vterm/vterm.c
@@ -0,0 +1,72 @@
+#include "vterm.h"
+#include <camellia/syscalls.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <camellia/compat.h>
+
+struct point cursor = {0};
+
+void in_char(char c) {
+	switch (c) {
+		case '\n':
+			cursor.x = 0;
+			cursor.y++;
+			break;
+		case '\b':
+			if (cursor.x > 0) cursor.x--;
+			break;
+		case '\t':
+			/* rounds down to nearest multiple of 8 and adds 8
+			   = adding 1 and rounding up to the nearest multiple of 8 */
+			cursor.x = (cursor.x & ~7) + 8;
+			break;
+		default:
+			font_blit(c, cursor.x, cursor.y);
+			cursor.x++;
+	}
+
+	if (cursor.x * font.w >= fb.width) {
+		cursor.x = 0;
+		cursor.y++;
+	}
+	while ((cursor.y + 1) * font.h >= fb.height) scroll();
+}
+
+int main(void) {
+	if (fb_setup(&fb, "/kdev/video/") < 0) {
+		eprintf("fb_setup error");
+		return 1;
+	}
+	font_load("/init/usr/share/fonts/spleen/spleen-8x16.psfu");
+
+	static char buf[512];
+	struct ufs_request res;
+	while (!c0_fs_wait(buf, sizeof buf, &res)) {
+		switch (res.op) {
+			case VFSOP_OPEN:
+				// TODO check path
+				c0_fs_respond(NULL, 0, 0);
+				break;
+
+			case VFSOP_WRITE:
+				if (res.flags) {
+					c0_fs_respond(NULL, -1, 0);
+				} else {
+					for (size_t i = 0; i < res.len; i++)
+						in_char(buf[i]);
+					dirty_flush(&dirty, &fb);
+					c0_fs_respond(NULL, res.len, 0);
+				}
+				break;
+
+			default:
+				c0_fs_respond(NULL, -1, 0);
+				break;
+		}
+	}
+
+	return 1;
+}
diff --git a/src/cmd/vterm/vterm.h b/src/cmd/vterm/vterm.h
new file mode 100644
index 0000000..026e71a
--- /dev/null
+++ b/src/cmd/vterm/vterm.h
@@ -0,0 +1,39 @@
+#pragma once
+#include <camellia/types.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <draw.h>
+
+#define eprintf(fmt, ...) fprintf(stderr, "vterm: "fmt"\n" __VA_OPT__(,) __VA_ARGS__)
+
+
+struct psf1 {
+    uint16_t magic;
+	uint8_t mode;
+	uint8_t h;
+} __attribute__((packed));
+struct psf2 {
+    uint32_t magic;
+    uint32_t version;
+    uint32_t glyph_offset;
+    uint32_t flags;
+    uint32_t glyph_amt;
+    uint32_t glyph_size;
+    uint32_t h;
+    uint32_t w;
+} __attribute__((packed));
+extern struct psf2 font;
+extern void *font_data;
+void font_load(const char *path);
+void font_blit(uint32_t glyph, int x, int y);
+
+extern struct framebuf fb;
+
+extern struct rect dirty;
+void vdirty_mark(uint32_t x, uint32_t y);
+void flush(void);
+void scroll(void);
+
+struct point {uint32_t x, y;};
+extern struct point cursor;
+void in_char(char c);