iris/userspace/glue/font.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// source/font.ccp: Font manager.
// Copyright 2012 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "devices.hh"

#define screenw 320
#define screenh 240

struct Glyph:
	unsigned width, height, baseline
	unsigned data[1]

static Iris::Display display
static Iris::Caps caps, display_caps
static unsigned slot, num_glyphs
static unsigned long pages, base
static Glyph **glyphs
static char *fb
static unsigned x, y

static unsigned read_int (unsigned addr):
	return *reinterpret_cast <unsigned *> (addr)

static void load_font (Iris::Block font):
	unsigned long long size = font.get_size ().value ()
	pages = (size + PAGE_SIZE - 1) >> PAGE_BITS
	caps = Iris::my_memory.create_caps (pages)
	slot = caps.use ()
	for unsigned i = 0; i < size; i += PAGE_SIZE:
		Iris::Page page = Iris::Cap (slot, i >> PAGE_BITS)
		Iris::set_recv_arg (page)
		font.get_block (i)
		Iris::my_memory.map (page, base + i)
	num_glyphs = read_int (base)
	glyphs = reinterpret_cast <Glyph **> (base + sizeof (int))
	for unsigned i = 0; i < num_glyphs; ++i:
		glyphs[i] = reinterpret_cast <Glyph *> (base + sizeof (int) + read_int (base + sizeof (int) + i * sizeof (int)))

static void free_font ():
	for unsigned i = 0; i < pages; ++i:
		Iris::my_memory.destroy (Iris::Cap (slot, i))
	Iris::my_memory.destroy (caps)
	Iris::free_slot (slot)

static unsigned draw_char (char c, unsigned &w, unsigned &h):
	if c >= num_glyphs:
		c = num_glyphs - 1
	Glyph *g = glyphs[c]
	w = g->width
	h = g->height
	for unsigned ty = 0; ty < h; ++ty:
		unsigned py = ty + y - g->baseline
		if py < 0 || py >= screenh:
			continue
		for unsigned tx = 0; tx < g->width; ++tx:
			unsigned px = tx + x
			if px < 0 || px >= screenw:
				continue
			unsigned p = g->data[ty * g->width + tx]
			unsigned red = unsigned (p) & 0xff
			unsigned green = unsigned (p >> 8) & 0xff
			unsigned blue = unsigned (p >> 16) & 0xff
			unsigned alpha = (unsigned (p >> 24) & 0xff) + 1
			if alpha == 0x100:
				fb[(py * 320 + px) * 4 + 2] = red
				fb[(py * 320 + px) * 4 + 1] = green
				fb[(py * 320 + px) * 4 + 0] = blue
			else:
				unsigned unalpha = 256 - alpha
				fb[(py * 320 + px) * 4 + 2] = (fb[(py * 320 + px) * 4 + 2] * unalpha + red * alpha) >> 8
				fb[(py * 320 + px) * 4 + 1] = (fb[(py * 320 + px) * 4 + 1] * unalpha + green * alpha) >> 8
				fb[(py * 320 + px) * 4 + 0] = (fb[(py * 320 + px) * 4 + 0] * unalpha + blue * alpha) >> 8
	return g->baseline

static void get_size (char c, unsigned &w, unsigned &h, unsigned &b):
	if c >= num_glyphs:
		c = num_glyphs - 1
	Glyph *g = glyphs[c]
	w = g->width
	h = g->height
	b = g->baseline

Iris::Num start ():
	x = 0
	y = 8
	// Random address which is large enough to store a huge file.
	base = 0x40000000
	fb = reinterpret_cast <char *> (0x20000000)
	Iris::Font self = Iris::my_receiver.create_capability (0)
	Iris::my_parent.provide_capability <Iris::Font> (self.copy ())
	Iris::free_cap (self)
	Iris::Block font = Iris::my_parent.get_capability <Iris::Block> ()
	load_font (font)
	Iris::free_cap (font)
	Iris::my_parent.init_done ()
	bool have_display = false
	while true:
		Iris::wait ()
		switch Iris::recv.data[0].l:
			case Iris::Font::SET_DISPLAY:
				Iris::Cap reply = Iris::get_reply ()
				if have_display:
					Iris::free_cap (display)
				have_display = true
				display = Iris::get_arg ()
				display_caps = display.map_fb (reinterpret_cast <unsigned> (fb))
				reply.invoke ()
				Iris::free_cap (reply)
				break
			case Iris::Font::LOAD_FONT:
				free_font ()
				font = Iris::get_arg ()
				load_font (font)
				Iris::free_cap (font)
				Iris::recv.reply.invoke ()
				break
			case Iris::Font::SETUP:
				// TODO: interface needs to be defined.
				Iris::recv.reply.invoke ()
				break
			case Iris::Font::AT:
				if Iris::recv.data[0].h & 1:
					x += Iris::recv.data[1].l
					if x > screenw:
						x = 0
						y += 16
						if y + 16 > screenh + 8:
							y = 8
				else:
					x = Iris::recv.data[1].l
				if Iris::recv.data[0].h & 2:
					y += Iris::recv.data[1].h
					if y + 16 > screenh + 8:
						y = 8
				else:
					y = Iris::recv.data[1].h
				Iris::recv.reply.invoke ()
				break
			case Iris::Font::WRITE:
				Iris::Cap reply = Iris::get_reply ()
				unsigned w, h
				unsigned b = draw_char (Iris::recv.data[1].l, w, h)
				x += w
				if x + w > screenw:
					x = 0
					y += h
					if y + h > screenh + b:
						y = b
				reply.invoke ()
				Iris::free_cap (reply)
				break
			case Iris::Font::GET_POS:
				Iris::recv.reply.invoke (x, y)
				break
			case Iris::Font::GET_SIZE:
				unsigned w, h, b
				get_size (Iris::recv.data[1].l, w, h, b)
				Iris::recv.reply.invoke (Iris::Num (b, h), w)
				break
			default:
				Iris::panic (0, "invalid operation type for lcd")
				break