/*
 * Frame buffer low level functions for QEmacs
 * Copyright (c) 2001, 2002 Fabrice Bellard.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "qe.h"
#include "cfb.h"
#include "fbfrender.h"

static unsigned int cfb15_get_color(unsigned int color)
{
    unsigned int r, g, b;

    r = (color >> 16) & 0xff;
    g = (color >> 8) & 0xff;
    b = (color) & 0xff;
    return ((((r) >> 3) << 10) | (((g) >> 3) << 5) | ((b) >> 3));
}

static unsigned int cfb16_get_color(unsigned int color)
{
    unsigned int r, g, b;

    r = (color >> 16) & 0xff;
    g = (color >> 8) & 0xff;
    b = (color) & 0xff;
    return ((((r) >> 3) << 11) | (((g) >> 2) << 5) | ((b) >> 3));
}

static unsigned int cfb24_get_color(unsigned int color)
{
    return color & 0xffffff;
}

static void cfb16_fill_rectangle(QEditScreen *s,
                                 int x1, int y1, int w, int h, QEColor color)
{
    CFBContext *cfb = s->private;
    unsigned char *dest, *d;
    int y, n;
    unsigned int col;

    col = cfb->get_color(color);
    col = (col << 16) | col;

    dest = cfb->base + y1 * cfb->wrap + x1 * 2;
    if (color == QECOLOR_XOR) {
        /* XXX: suppress this mess */
        for(y=0;y<h;y++) {
            d = dest;
            for(n = w; n != 0; n--) {
                ((short *)d)[0] ^= 0xffff;
                d += 2;
            }
            dest += cfb->wrap;
        }
    } else {
        for(y=0;y<h;y++) {
            d = dest;
            n = w;
            
            if (((int)d & 3) != 0) {
                ((short *)d)[0] = col;
                d += 2;
                n--;
            }
            
            while (n >= 8) {
                ((int *)d)[0] = col;
                ((int *)d)[1] = col;
                ((int *)d)[2] = col;
                ((int *)d)[3] = col;
                d += 16;
                n -= 8;
            }
            while (n > 0) {
                ((short *)d)[0] = col;
                d += 2;
                n--;
            }
            dest += cfb->wrap;
        }
    }
}

static void cfb32_fill_rectangle(QEditScreen *s,
                                 int x1, int y1, int w, int h, QEColor color)
{
    CFBContext *cfb = s->private;
    unsigned char *dest, *d;
    int y, n;
    unsigned int col;
    col = cfb->get_color(color);

    dest = cfb->base + y1 * cfb->wrap + x1 * 4;
    if (color == QECOLOR_XOR) {
        /* XXX: suppress this mess */
        for(y=0;y<h;y++) {
            d = dest;
            for(n = w; n != 0; n--) {
                ((short *)d)[0] ^= 0x00ffffff;
                d += 4;
            }
            dest += cfb->wrap;
        }
    } else {
        for(y=0;y<h;y++) {
            d = dest;
            n = w;
            while (n >= 4) {
                ((int *)d)[0] = col;
                ((int *)d)[1] = col;
                ((int *)d)[2] = col;
                ((int *)d)[3] = col;
                d += 16;
                n -= 4;
            }
            while (n > 0) {
                ((int *)d)[0] = col;
                d += 4;
                n--;
            }
            dest += cfb->wrap;
        }
    }
}

static void cfb16_draw_glyph(QEditScreen *s1,
                             int x1, int y1, int w, int h, QEColor color,
                             unsigned char *glyph, int glyph_wrap)
{
    CFBContext *cfb = s1->private;
    unsigned char *dest, *d, *s, *src;
    int n;
    unsigned int col;

    col = cfb->get_color(color);
    dest = cfb->base + y1 * cfb->wrap + x1 * 2;
    src = glyph;

    while (h > 0) {
        n = w;
        s = src;
        d = dest;
        while (n >= 4) {
            if (s[0] >= 0x80)
                ((short *)d)[0] = col;
            if (s[1] >= 0x80)
                ((short *)d)[1] = col;
            if (s[2] >= 0x80)
                ((short *)d)[2] = col;
            if (s[3] >= 0x80)
                ((short *)d)[3] = col;
            s += 4;
            d += 4 * 2;
            n -= 4;
        }
        while (n > 0) {
            if (s[0] >= 0x80)
                ((short *)d)[0] = col;
            s++;
            d += 2;
            n--;
        }

        h--;
        src += glyph_wrap;
        dest += cfb->wrap;
    }
}

static void cfb32_draw_glyph(QEditScreen *s1,
                             int x1, int y1, int w, int h, QEColor color,
                             unsigned char *glyph, int glyph_wrap)
{
    CFBContext *cfb = s1->private;
    unsigned char *dest, *d, *s, *src;
    int n;
    unsigned int col;

    col = cfb->get_color(color);
    dest = cfb->base + y1 * cfb->wrap + x1 * 4;
    src = glyph;

    while (h > 0) {
        n = w;
        s = src;
        d = dest;
        while (n >= 4) {
            if (s[0] >= 0x80)
                ((int *)d)[0] = col;
            if (s[1] >= 0x80)
                ((int *)d)[1] = col;
            if (s[2] >= 0x80)
                ((int *)d)[2] = col;
            if (s[3] >= 0x80)
                ((int *)d)[3] = col;
            s += 4;
            d += 4 * 4;
            n -= 4;
        }
        while (n > 0) {
            if (s[0] >= 0x80)
                ((int *)d)[0] = col;
            s++;
            d += 4;
            n--;
        }

        h--;
        src += glyph_wrap;
        dest += cfb->wrap;
    }
}

static void cfb_draw_text(QEditScreen *s, QEFont *font,
                           int x_start, int y, const unsigned int *str, int len,
                           QEColor color)
{
    CFBContext *cfb = s->private;
    GlyphCache *g;
    unsigned char *glyph_ptr;
    int i, x1, y1, x2, y2, wrap, x;
    unsigned int cc;

    x = x_start;
    for (i = 0;i < len; i++) {
        cc = str[i];
        g = decode_cached_glyph(s, font, cc);
        if (!g)
            continue;

        x1 = x + g->x;
        x2 = x1 + g->w;
        y2 = y - g->y;
        y1 = y2 - g->h;
        glyph_ptr = g->data;
        wrap = g->w;

        if (x1 >= s->clip_x1 && y1 >= s->clip_y1 &&
            x2 <= s->clip_x2 && y2 <= s->clip_y2)
            goto draw;
        
        if (x2 <= s->clip_x1 || y2 <= s->clip_y1 ||
            x1 >= s->clip_x2 || y1 >= s->clip_y2)
            goto nodraw;
        
        if (x1 < s->clip_x1) {
            glyph_ptr += s->clip_x1 - x1;
            x1 = s->clip_x1;
        }
        if (x2 > s->clip_x2)
            x2 = s->clip_x2;
        if (y1 < s->clip_y1) {
            glyph_ptr += (s->clip_y1 - y1) * wrap;
            y1 = s->clip_y1;
        }
        if (y2 > s->clip_y2)
            y2 = s->clip_y2;
    draw:
        cfb->draw_glyph(s, x1, y1, 
                        x2 - x1, y2 - y1, 
                        color, glyph_ptr, wrap);
    nodraw:
        x += g->xincr;
    }

    /* underline synthesis */
    if (font->style & (QE_STYLE_UNDERLINE | QE_STYLE_LINE_THROUGH)) {
        int dy, h, w;
        h = (font->descent + 2) / 4;
        if (h < 1)
            h = 1;
        w = x - x_start;
        if (font->style & QE_STYLE_UNDERLINE) {
            dy = (font->descent + 1) / 3;
            fill_rectangle(s, x_start, y + dy, w, h, color);
        }
        if (font->style & QE_STYLE_LINE_THROUGH) {
            dy = -(font->ascent / 2 - 1);
            fill_rectangle(s, x_start, y + dy, w, h, color);
        }
    }
}


static void cfb_set_clip(QEditScreen *s,
                         int x, int y, int w, int h)
{
}

int cfb_init(QEditScreen *s, 
             void *base, int wrap, int depth, const char *font_path)
{
    CFBContext *cfb = s->private;

    cfb->base = base;
    cfb->wrap = wrap;
    cfb->depth = depth;
    cfb->bpp = (depth + 7) / 8;
    
    switch(depth) {
    case 15:
        cfb->get_color = cfb15_get_color;
        break;
    case 16:
        cfb->get_color = cfb16_get_color;
        break;
    case 24:
    default:
        cfb->get_color = cfb24_get_color;
        break;
    }

    switch(cfb->bpp) {
    case 2:
        s->dpy.dpy_fill_rectangle = cfb16_fill_rectangle;
        cfb->draw_glyph = cfb16_draw_glyph;
       break;
    default:
    case 4:
        s->dpy.dpy_fill_rectangle = cfb32_fill_rectangle;
        cfb->draw_glyph = cfb32_draw_glyph;
        break;
    }

    s->dpy.dpy_set_clip = cfb_set_clip;
    s->dpy.dpy_draw_text = cfb_draw_text;

    /* fbf font handling init */
    s->dpy.dpy_text_metrics = fbf_text_metrics;
    s->dpy.dpy_open_font = fbf_open_font;
    s->dpy.dpy_close_font = fbf_close_font;
    
    return fbf_render_init(font_path);
}