src/drivers/display/framebuffer.c

/*
 * Copyright 2016 Google Inc.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include "base/container_of.h"
#include "base/xalloc.h"
#include "drivers/display/framebuffer.h"

static int fb_display_initialize(FbDisplay *display)
{
	if (display->fb_info.buffer)
		return 0;

	if (framebuffer_prepare(display->framebuffer, &display->fb_info)) {
		display->fb_info.buffer = NULL;
		return 1;
	}

	if (display->monitor && monitor_enable(display->monitor))
		return 1;

	return 0;
}

static inline void fb_display_set_pixel(FbDisplay *display,
					uint32_t x, uint32_t y, uint32_t color)
{
	const uint32_t xres = display->fb_info.resolution.x;
	const uint8_t bpp = display->fb_info.bits_per_pixel;

	uint8_t *pixel = display->fb_info.buffer + (x + y * xres) * bpp / 8;
	for (int i = 0; i < bpp / 8; i++)
		pixel[i] = (color >> (i * 8));
}

static int fb_display_dimensions(DisplayOps *me,
				 uint32_t *height, uint32_t *width)
{
	FbDisplay *display = container_of(me, FbDisplay, ops);

	if (fb_display_initialize(display))
		return 1;

	*height = display->fb_info.resolution.y;
	*width = display->fb_info.resolution.x;

	return 0;
}

static int fb_display_fill(DisplayOps *me, uint32_t x, uint32_t y,
			   uint32_t height, uint32_t width,
			   const DcColor *color)
{
	FbDisplay *display = container_of(me, FbDisplay, ops);

	if (fb_display_initialize(display))
		return 1;

	if (height == 0 || width == 0)
		return 0;

	const uint32_t pval = framebuffer_pixel_value(&display->fb_info, color);

	for (uint32_t offy = 0; offy < height; offy++) {
		for (uint32_t offx = 0; offx < width; offx++) {
			fb_display_set_pixel(display, x + offx,
					     y + offy, pval);
		}
	}
	return 0;
}

static void fb_display_move_row(FbDisplay *display, uint32_t x, uint32_t y,
				uint32_t new_x, uint32_t new_y, uint32_t width)
{
	const uint32_t xres = display->fb_info.resolution.x;
	const uint8_t bpp = display->fb_info.bits_per_pixel;

	uint8_t *from = display->fb_info.buffer + (x + y * xres) * bpp / 8;
	uint8_t *to = display->fb_info.buffer +
		(new_x + new_y * xres) * bpp / 8;
	memmove(to, from, width * bpp / 8);
}

static int fb_display_move(DisplayOps *me, uint32_t x, uint32_t y,
			   uint32_t new_x, uint32_t new_y,
			   uint32_t height, uint32_t width)
{
	FbDisplay *display = container_of(me, FbDisplay, ops);

	if (fb_display_initialize(display))
		return 1;

	if (height == 0 || width == 0)
		return 0;

	for (uint32_t y_idx = 0; y_idx < height; y_idx++) {
		uint32_t offy = (new_y > y) ? (height - y_idx - 1) : y_idx;
		fb_display_move_row(display, x, y + offy, new_x,
				    new_y + offy, width);
	}

	return 0;
}

static int fb_display_draw(DisplayOps *me, uint32_t x, uint32_t y,
			   const DcBitmap *bitmap)
{
	FbDisplay *display = container_of(me, FbDisplay, ops);

	if (fb_display_initialize(display))
		return 1;

	DcColor *pixel = bitmap->pixels;
	for (uint32_t offy = 0; offy < bitmap->height; offy++) {
		for (uint32_t offx = 0; offx < bitmap->width; offx++) {
			uint32_t pval = framebuffer_pixel_value(
				&display->fb_info, pixel++);
			fb_display_set_pixel(display, x + offx,
					     y + offy, pval);
		}
	}

	return 0;
}

FbDisplay *new_fb_display(FrameBufferOps *framebuffer, MonitorOps *monitor)
{
	FbDisplay *display = xzalloc(sizeof(*display));

	display->ops.dimensions = &fb_display_dimensions;
	display->ops.fill = &fb_display_fill;
	display->ops.move = &fb_display_move;
	display->ops.draw = &fb_display_draw;

	display->framebuffer = framebuffer;
	display->monitor = monitor;

	return display;
}