/*      $NetBSD: fb.c,v 1.5 2017/08/27 02:19:08 jmcneill Exp $  */

/*-
 * Copyright (c) 2002 TAKEMRUA Shin
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/mman.h>

#include "tpctl.h"

#ifndef lint
#include <sys/cdefs.h>
__RCSID("$NetBSD: fb.c,v 1.5 2017/08/27 02:19:08 jmcneill Exp $");
#endif /* not lint */

#define INVALID_CACHE -1
#define ALIGN(a, n)     ((typeof(a))(((int)(a) + (n) - 1) / (n) * (n)))
#define ABS(a)          ((a) < 0 ? -(a) : (a))
#define SWAP(a, b)      do {                            \
                typeof(a) tmp;                          \
                tmp = (a); (a) = (b); (b) = tmp;        \
        } while(0)
#define bitsizeof(t)    (sizeof(t) * 8)

int
fb_dispmode(struct fb *fb, int dispmode)
{

        if (fb->dispmode != dispmode) {
            if (ioctl(fb->fd, WSDISPLAYIO_SMODE, &dispmode) < 0)
                return (-1);
            fb->dispmode = dispmode;
        }

        return (0);
}

int
fb_init(struct fb *fb, int fd)
{
        struct wsdisplay_fbinfo fbinfo;
        u_int linebytes;
        int y;
        size_t size;

        fb->fd = fd;
        fb->linecache_y = INVALID_CACHE;
        fb->conf.hf_conf_index = HPCFB_CURRENT_CONFIG;
        if (ioctl(fb->fd, WSDISPLAYIO_GMODE, &fb->dispmode) < 0)
                return (-1);
        if (ioctl(fb->fd, HPCFBIO_GCONF, &fb->conf) < 0) {
                if (ioctl(fb->fd, WSDISPLAYIO_GINFO, &fbinfo) < 0 ||
                    ioctl(fb->fd, WSDISPLAYIO_LINEBYTES, &linebytes) < 0)
                        return (-1);
                memset(&fb->conf, 0, sizeof(fb->conf));
                fb->conf.hf_width = fbinfo.width;
                fb->conf.hf_height = fbinfo.height;
                fb->conf.hf_bytes_per_line = linebytes;
                fb->conf.hf_nplanes = 1;
                fb->conf.hf_bytes_per_plane = fbinfo.height * linebytes;
                fb->conf.hf_pack_width = fbinfo.depth;
                fb->conf.hf_pixels_per_pack = 1;
                fb->conf.hf_pixel_width = 1;
                fb->conf.hf_access_flags = HPCFB_ACCESS_STATIC |
                    HPCFB_ACCESS_BYTE | HPCFB_ACCESS_WORD | HPCFB_ACCESS_DWORD;
        }

        if (fb_dispmode(fb, WSDISPLAYIO_MODE_MAPPED) < 0)
                return (-1);

        size = (size_t)fb->conf.hf_bytes_per_line * fb->conf.hf_height;
        size += fb->conf.hf_offset;
        size = ALIGN(size, getpagesize());
        fb->baseaddr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,0);
        if (fb->baseaddr == MAP_FAILED)
                return (-1);
        fb->baseaddr += fb->conf.hf_offset;

        size = ALIGN(fb->conf.hf_bytes_per_line, 16);
        fb->linecache = (fb_pixel_t*)malloc(size);
        if (fb->linecache == NULL)
                return (-1);
        fb->workbuf = (fb_pixel_t*)malloc(size);
        if (fb->workbuf == NULL)
                return (-1);

        if (fb->conf.hf_access_flags & HPCFB_ACCESS_REVERSE) {
                fb->white = 0;
                fb->black = ~0;
        } else {
                fb->white = ~0;
                fb->black = 0;
        }

        /*
         * clear screen
         */
        for (y = 0; y < fb->conf.hf_height; y++) {
                fb_getline(fb, y);
                memset(fb->linecache, fb->black,
                    ALIGN(fb->conf.hf_bytes_per_line, 16));
                fb_putline(fb, y);
        }

        return (0);
}

static void
__fb_swap_workbuf(struct fb *fb)
{
        int i, n;

        n = ALIGN(fb->conf.hf_bytes_per_line, 16) / sizeof(fb_pixel_t);
        if (fb->conf.hf_order_flags & HPCFB_REVORDER_BYTE) {
                for (i = 0; i < n; i++)
                        fb->workbuf[i] = 
                            ((fb->workbuf[i] << 8) & 0xff00ff00) |
                            ((fb->workbuf[i] >> 8) & 0x00ff00ff);
        }
        if (fb->conf.hf_order_flags & HPCFB_REVORDER_WORD) {
                for (i = 0; i < n; i++)
                        fb->workbuf[i] = 
                            ((fb->workbuf[i] << 16) & 0xffff0000) |
                            ((fb->workbuf[i] >> 16) & 0x0000ffff);
        }
        if (fb->conf.hf_order_flags & HPCFB_REVORDER_DWORD) {
                for (i = 0; i < n; i += 2) {
                        fb_pixel_t tmp;
                        tmp = fb->workbuf[i];
                        fb->workbuf[i] = fb->workbuf[i + 1];
                        fb->workbuf[i + 1] = tmp;
                }
        }
        if (fb->conf.hf_order_flags & HPCFB_REVORDER_QWORD) {
                for (i = 0; i < n; i += 4) {
                        fb_pixel_t tmp;
                        tmp = fb->workbuf[i + 0];
                        fb->workbuf[i + 0] = fb->workbuf[i + 2];
                        fb->workbuf[i + 2] = tmp;
                        tmp = fb->workbuf[i + 1];
                        fb->workbuf[i + 1] = fb->workbuf[i + 3];
                        fb->workbuf[i + 3] = tmp;
                }
        }
}

static void
__fb_put_pixel(struct fb *fb, fb_pixel_t pixel, int width, int x)
{
        fb_pixel_t mask = (1 << width) - 1;

        x -= (bitsizeof(fb_pixel_t) - width);
        if (x < 0) {
                pixel <<= -x;
                mask <<= -x;
                fb->linecache[0] = (fb->linecache[0]&~mask) | (pixel&~mask);
        } else {
                fb_pixel_t *dst = &fb->linecache[x / bitsizeof(fb_pixel_t)];
                x %= bitsizeof(fb_pixel_t);
                *dst = (*dst & ~(mask>>x)) | ((pixel>>x) & (mask>>x));
                dst++;
                if (x == 0)
                        return;
                x = bitsizeof(fb_pixel_t) - x;
                *dst = (*dst & ~(mask<<x)) | ((pixel<<x) & (mask<<x));
        }
}

void
fb_getline(struct fb *fb, int y)
{
        int i, n;
        unsigned char *src;
        fb_pixel_t *dst;

        src = fb->baseaddr + fb->conf.hf_bytes_per_line * y;
        dst = fb->workbuf;
        n = ALIGN(fb->conf.hf_bytes_per_line, 16) / sizeof(fb_pixel_t);
        for (i = 0; i < n; i++) {
                *dst++ = ((fb_pixel_t)src[0] << 24) | 
                    ((fb_pixel_t)src[1] << 16) | 
                    ((fb_pixel_t)src[2] << 8) | 
                    ((fb_pixel_t)src[3] << 0);
                src += 4;
        }

        __fb_swap_workbuf(fb);
        memcpy(fb->linecache, fb->workbuf, n * sizeof(fb_pixel_t));
}

void
fb_putline(struct fb *fb, int y)
{
        int i, n;
        unsigned char *dst;
        fb_pixel_t *src;

        src = fb->workbuf;
        dst = fb->baseaddr + fb->conf.hf_bytes_per_line * y;
        n = ALIGN(fb->conf.hf_bytes_per_line, 16) / sizeof(fb_pixel_t);
        memcpy(fb->workbuf, fb->linecache, n * sizeof(fb_pixel_t));
        __fb_swap_workbuf(fb);
        for (i = 0; i < n; i++) {
                *dst++ = (*src >> 24) & 0xff;
                *dst++ = (*src >> 16) & 0xff;
                *dst++ = (*src >>  8) & 0xff;
                *dst++ = (*src >>  0) & 0xff;
                src++;
        }
}

void
fb_fetchline(struct fb *fb, int y)
{
        if (fb->linecache_y == y)
                return;
        fb_getline(fb, y);
        fb->linecache_y = y;
}

void
fb_flush(struct fb *fb)
{
        if (fb->linecache_y != INVALID_CACHE)
                fb_putline(fb, fb->linecache_y);
}

void
fb_drawpixel(struct fb *fb, int x, int y, fb_pixel_t pixel)
{
        int pack;

        if (fb->conf.hf_access_flags & HPCFB_ACCESS_Y_TO_X)
                SWAP(x, y);
        if (fb->conf.hf_access_flags & HPCFB_ACCESS_R_TO_L)
                x = fb->conf.hf_width - x - 1;
        if (fb->conf.hf_access_flags & HPCFB_ACCESS_B_TO_T)
                y = fb->conf.hf_height - y - 1;

        if (x < 0 || y < 0 || fb->conf.hf_width <= x || fb->conf.hf_height < y)
                return;

        pack = x / fb->conf.hf_pixels_per_pack;
        x %= fb->conf.hf_pixels_per_pack;
        if (fb->conf.hf_access_flags & HPCFB_ACCESS_LSB_TO_MSB)
                x = fb->conf.hf_pixels_per_pack - x - 1;
        x *= fb->conf.hf_pixel_width;
        if (fb->conf.hf_access_flags & HPCFB_ACCESS_PACK_BLANK)
                x += (fb->conf.hf_pack_width - 
                    fb->conf.hf_pixel_width * fb->conf.hf_pixels_per_pack);
        x += pack * fb->conf.hf_pack_width;

        if (fb->linecache_y != y) {
                fb_flush(fb);
                fb_fetchline(fb, y);
        }

        __fb_put_pixel(fb, pixel, fb->conf.hf_pixel_width, x);
}

void
fb_drawline(struct fb *fb, int x0, int y0, int x1, int y1, fb_pixel_t pixel)
{
        int i, dx, dy, d, incdec;

        dx = ABS(x1 - x0);
        dy = ABS(y1 - y0);
        if (dx < dy) {
                if (y1 < y0) {
                        SWAP(x0, x1);
                        SWAP(y0, y1);
                }
                if (x0 < x1)
                        incdec = 1;
                else
                        incdec = -1;
                d = -dy;
                dx *= 2;
                dy *= 2;
                for (i = y0; i <= y1; i++) {
                        fb_drawpixel(fb, x0, i, pixel);
                        d += dx;
                        if (0 <= d) {
                                d -= dy;
                                x0 += incdec;
                        }
                }
        } else {
                if (x1 < x0) {
                        SWAP(x0, x1);
                        SWAP(y0, y1);
                }
                if (y0 < y1)
                        incdec = 1;
                else
                        incdec = -1;
                d = -dx;
                dx *= 2;
                dy *= 2;
                for (i = x0; i <= x1; i++) {
                        fb_drawpixel(fb, i, y0, pixel);
                        d += dy;
                        if (0 <= d) {
                                d -= dx;
                                y0 += incdec;
                        }
                }
        }
}