netsurf/frontends/beos/bitmap.cpp

/*
 * Copyright 2008 François Revol <mmu_man@users.sourceforge.net>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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/>.
 */

/**
 * \file
 * BeOS implementation of generic bitmaps.
 *
 * This implements the interface given by image/bitmap.h using BBitmap.
 */

#define __STDBOOL_H__	1
#include <assert.h>
#include <sys/param.h>
#include <string.h>
#include <Bitmap.h>
#include <BitmapStream.h>
#include <File.h>
#include <GraphicsDefs.h>
#include <TranslatorFormats.h>
#include <TranslatorRoster.h>
#include <View.h>
#include <stdlib.h>

extern "C" {
#include "utils/log.h"
#include "content/content.h"
#include "content/urldb.h"
#include "desktop/plotters.h"
#include "desktop/browser.h"
#include "image/bitmap.h"
}

#include "beos/bitmap.h"
#include "beos/gui.h"
#include "beos/scaffolding.h"
#include "beos/plotters.h"


struct bitmap {
        BBitmap *primary;
        BBitmap *shadow; // in NetSurf's ABGR order
        BBitmap *pretile_x;
        BBitmap *pretile_y;
        BBitmap *pretile_xy;
        bool opaque;
};

#define MIN_PRETILE_WIDTH 256
#define MIN_PRETILE_HEIGHT 256

#warning TODO: check rgba order
#warning TODO: add correct locking (not strictly required)


/**
 * Convert to BeOS RGBA32_LITTLE (strictly BGRA) from NetSurf's favoured ABGR format.
 *
 * Copies the converted data elsewhere.  Operation is rotate left 8 bits.
 *
 * \param src       Source 32-bit pixels arranged in ABGR order.
 * \param dst       Output data in BGRA order.
 * \param width     Width of the bitmap
 * \param height    Height of the bitmap
 * \param rowstride Number of bytes to skip after each row (this implementation
 *                  requires this to be a multiple of 4.)
 */
static inline void nsbeos_rgba_to_bgra(void *src,
                                       void *dst,
                                       int width,
                                       int height,
                                       size_t rowstride)
{
        struct abgr { uint8 a, b, g, r; };
        struct rgba { uint8 r, g, b ,a; };
        struct bgra { uint8 b, g, r, a; };
        struct rgba *from = (struct rgba *)src;
        struct bgra *to = (struct bgra *)dst;

        rowstride >>= 2;

        for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                        to[x].b = from[x].b;
                        to[x].g = from[x].g;
                        to[x].r = from[x].r;
                        to[x].a = from[x].a;
                        /*
                          if (from[x].a == 0)
                          *(rgb_color *)&to[x] = B_TRANSPARENT_32_BIT;
                          */
                }
                from += rowstride;
                to += rowstride;
        }
}


/**
 * Create a bitmap.
 *
 * \param  width   width of image in pixels
 * \param  height  width of image in pixels
 * \param  state   a flag word indicating the initial state
 * \return an opaque struct bitmap, or NULL on memory exhaustion
 */
static void *bitmap_create(int width, int height, unsigned int state)
{
        struct bitmap *bmp = (struct bitmap *)malloc(sizeof(struct bitmap));
        if (bmp == NULL)
                return NULL;

        int32 flags = 0;
        if (state & BITMAP_CLEAR_MEMORY)
                flags |= B_BITMAP_CLEAR_TO_WHITE;

        BRect frame(0, 0, width - 1, height - 1);
        //XXX: bytes per row ?
        bmp->primary = new BBitmap(frame, flags, B_RGBA32);
        bmp->shadow = new BBitmap(frame, flags, B_RGBA32);

        bmp->pretile_x = bmp->pretile_y = bmp->pretile_xy = NULL;

        bmp->opaque = (state & BITMAP_OPAQUE) != 0;

        return bmp;
}


/**
 * Sets whether a bitmap should be plotted opaque
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \param  opaque   whether the bitmap should be plotted opaque
 */
static void bitmap_set_opaque(void *vbitmap, bool opaque)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        bitmap->opaque = opaque;
}


/**
 * Tests whether a bitmap has an opaque alpha channel
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \return whether  the bitmap is opaque
 */
static bool bitmap_test_opaque(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        /* todo: test if bitmap is opaque */
        return false;
}


/**
 * Gets whether a bitmap should be plotted opaque
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 */
static bool bitmap_get_opaque(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        return bitmap->opaque;
}


/**
 * Return a pointer to the pixel data in a bitmap.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \return pointer to the pixel buffer
 *
 * The pixel data is packed as BITMAP_FORMAT, possibly with padding at the end
 * of rows. The width of a row in bytes is given by bitmap_get_rowstride().
 */

static unsigned char *bitmap_get_buffer(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        return (unsigned char *)(bitmap->shadow->Bits());
}


/**
 * Find the width of a pixel row in bytes.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \return width of a pixel row in the bitmap
 */
static size_t bitmap_get_rowstride(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        return (bitmap->primary->BytesPerRow());
}


/**
 * Find the bytes per pixels of a bitmap.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \return bytes per pixels of the bitmap
 */
static size_t bitmap_get_bpp(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        return 4;
}


/**
 * Free pretiles of a bitmap.
 *
 * \param bitmap The bitmap to free the pretiles of.
 */
static void nsbeos_bitmap_free_pretiles(struct bitmap *bitmap)
{
#define FREE_TILE(XY) if (bitmap->pretile_##XY) delete (bitmap->pretile_##XY); bitmap->pretile_##XY = NULL
        FREE_TILE(x);
        FREE_TILE(y);
        FREE_TILE(xy);
#undef FREE_TILE
}


/**
 * Free a bitmap.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 */
static void bitmap_destroy(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        assert(bitmap);
        nsbeos_bitmap_free_pretiles(bitmap);
        delete bitmap->primary;
        delete bitmap->shadow;
        free(bitmap);
}


/**
 * Save a bitmap in the platform's native format.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 * \param  path     pathname for file
 * \param  flags    modify the behaviour of the save
 * \return true on success, false on error and error reported
 */
static bool bitmap_save(void *vbitmap, const char *path, unsigned flags)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        BTranslatorRoster *roster = BTranslatorRoster::Default();
        BBitmapStream stream(bitmap->primary);
        BFile file(path, B_WRITE_ONLY | B_CREATE_FILE);
        uint32 type = B_PNG_FORMAT;

        if (file.InitCheck() < B_OK)
                return false;

        if (roster->Translate(&stream, NULL, NULL, &file, type) < B_OK)
                return false;

        return true;
}


/**
 * The bitmap image has changed, so flush any persistant cache.
 *
 * \param  vbitmap  a bitmap, as returned by bitmap_create()
 */
void bitmap_modified(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        // convert the shadow (ABGR) to into the primary bitmap
        nsbeos_rgba_to_bgra(bitmap->shadow->Bits(), bitmap->primary->Bits(),
                            bitmap->primary->Bounds().Width() + 1,
                            bitmap->primary->Bounds().Height() + 1,
                            bitmap->primary->BytesPerRow());
        nsbeos_bitmap_free_pretiles(bitmap);
}


static int bitmap_get_width(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        return bitmap->primary->Bounds().Width() + 1;
}


static int bitmap_get_height(void *vbitmap)
{
        struct bitmap *bitmap = (struct bitmap *)vbitmap;
        return bitmap->primary->Bounds().Height() + 1;
}


static BBitmap *
nsbeos_bitmap_generate_pretile(BBitmap *primary, int repeat_x, int repeat_y)
{
        int width = primary->Bounds().Width() + 1;
        int height = primary->Bounds().Height() + 1;
        size_t primary_stride = primary->BytesPerRow();
        BRect frame(0, 0, width * repeat_x - 1, height * repeat_y - 1);
        BBitmap *result = new BBitmap(frame, 0, B_RGBA32);

        char *target_buffer = (char *)result->Bits();
        int x,y,row;
        /* This algorithm won't work if the strides are not multiples */
        assert((size_t)(result->BytesPerRow()) ==
               (primary_stride * repeat_x));

        if (repeat_x == 1 && repeat_y == 1) {
                delete result;
                // just return a copy
                return new BBitmap(primary);
        }

        for (y = 0; y < repeat_y; ++y) {
                char *primary_buffer = (char *)primary->Bits();
                for (row = 0; row < height; ++row) {
                        for (x = 0; x < repeat_x; ++x) {
                                memcpy(target_buffer,
                                       primary_buffer, primary_stride);
                                target_buffer += primary_stride;
                        }
                        primary_buffer += primary_stride;
                }
        }
        return result;

}


/**
 * The primary image associated with this bitmap object.
 *
 * \param  bitmap  a bitmap, as returned by bitmap_create()
 */
BBitmap *
nsbeos_bitmap_get_primary(struct bitmap* bitmap)
{
        return bitmap->primary;
}


/**
 * The X-pretiled image associated with this bitmap object.
 *
 * \param  bitmap  a bitmap, as returned by bitmap_create()
 */
BBitmap *
nsbeos_bitmap_get_pretile_x(struct bitmap* bitmap)
{
        if (!bitmap->pretile_x) {
                int width = bitmap->primary->Bounds().Width() + 1;
                int xmult = (MIN_PRETILE_WIDTH + width - 1)/width;
                LOG("Pretiling %p for X*%d", bitmap, xmult);
                bitmap->pretile_x = nsbeos_bitmap_generate_pretile(bitmap->primary, xmult, 1);
        }
        return bitmap->pretile_x;

}


/**
 * The Y-pretiled image associated with this bitmap object.
 *
 * \param  bitmap  a bitmap, as returned by bitmap_create()
 */
BBitmap *
nsbeos_bitmap_get_pretile_y(struct bitmap* bitmap)
{
        if (!bitmap->pretile_y) {
                int height = bitmap->primary->Bounds().Height() + 1;
                int ymult = (MIN_PRETILE_HEIGHT + height - 1)/height;
                LOG("Pretiling %p for Y*%d", bitmap, ymult);
                bitmap->pretile_y = nsbeos_bitmap_generate_pretile(bitmap->primary, 1, ymult);
        }
        return bitmap->pretile_y;
}


/**
 * The XY-pretiled image associated with this bitmap object.
 *
 * \param  bitmap  a bitmap, as returned by bitmap_create()
 */
BBitmap *
nsbeos_bitmap_get_pretile_xy(struct bitmap* bitmap)
{
        if (!bitmap->pretile_xy) {
                int width = bitmap->primary->Bounds().Width() + 1;
                int height = bitmap->primary->Bounds().Height() + 1;
                int xmult = (MIN_PRETILE_WIDTH + width - 1)/width;
                int ymult = (MIN_PRETILE_HEIGHT + height - 1)/height;
                LOG("Pretiling %p for X*%d Y*%d", bitmap, xmult, ymult);
                bitmap->pretile_xy = nsbeos_bitmap_generate_pretile(bitmap->primary, xmult, ymult);
        }
        return bitmap->pretile_xy;
}


/**
 * Create a thumbnail of a page.
 *
 * \param  bitmap   the bitmap to draw to
 * \param  content  content structure to thumbnail
 * \return true on success and bitmap updated else false
 */
static nserror bitmap_render(struct bitmap *bitmap, hlcache_handle *content)
{
        BBitmap *thumbnail;
        BBitmap *small;
        BBitmap *big;
        BView *oldView;
        BView *view;
        BView *thumbView;
        float width;
        float height;
        int big_width;
        int big_height;
        int depth;

        struct redraw_context ctx;
        ctx.interactive = false;
        ctx.background_images = true;
        ctx.plot = &nsbeos_plotters;

        assert(content);
        assert(bitmap);

        thumbnail = nsbeos_bitmap_get_primary(bitmap);
        width = thumbnail->Bounds().Width();
        height = thumbnail->Bounds().Height();
        depth = 32;

        big_width = MIN(content_get_width(content), 1024);
        big_height = (int)(((big_width * height) + (width / 2)) / width);

        BRect contentRect(0, 0, big_width - 1, big_height - 1);
        big = new BBitmap(contentRect, B_BITMAP_ACCEPTS_VIEWS, B_RGB32);

        if (big->InitCheck() < B_OK) {
                delete big;
                return NSERROR_NOMEM;
        }

        small = new BBitmap(thumbnail->Bounds(),
                            B_BITMAP_ACCEPTS_VIEWS, B_RGB32);

        if (small->InitCheck() < B_OK) {
                delete small;
                delete big;
                return NSERROR_NOMEM;
        }

        //XXX: _lock ?
        // backup the current gc
        oldView = nsbeos_current_gc();

        view = new BView(contentRect, "thumbnailer",
                         B_FOLLOW_NONE, B_WILL_DRAW);
        big->AddChild(view);

        thumbView = new BView(small->Bounds(), "thumbnail",
                              B_FOLLOW_NONE, B_WILL_DRAW);
        small->AddChild(thumbView);

        view->LockLooper();

        /* impose our view on the content... */
        nsbeos_current_gc_set(view);

        /* render the content */
        content_scaled_redraw(content, big_width, big_height, &ctx);

        view->Sync();
        view->UnlockLooper();

        // restore the current gc
        nsbeos_current_gc_set(oldView);


        // now scale it down
        //XXX: use Zeta's bilinear scaler ?
        //#ifdef B_ZETA_VERSION
        //	err = ScaleBitmap(*shot, *scaledBmp);
        //#else
        thumbView->LockLooper();
        thumbView->DrawBitmap(big, big->Bounds(), small->Bounds());
        thumbView->Sync();
        thumbView->UnlockLooper();

        small->LockBits();
        thumbnail->LockBits();

        // copy it to the bitmap
        memcpy(thumbnail->Bits(), small->Bits(), thumbnail->BitsLength());

        thumbnail->UnlockBits();
        small->UnlockBits();

        bitmap_modified(bitmap);

        // cleanup
        small->RemoveChild(thumbView);
        delete thumbView;
        delete small;
        big->RemoveChild(view);
        delete view;
        delete big;

        return NSERROR_OK;
}


static struct gui_bitmap_table bitmap_table = {
        /*.create =*/ bitmap_create,
        /*.destroy =*/ bitmap_destroy,
        /*.set_opaque =*/ bitmap_set_opaque,
        /*.get_opaque =*/ bitmap_get_opaque,
        /*.test_opaque =*/ bitmap_test_opaque,
        /*.get_buffer =*/ bitmap_get_buffer,
        /*.get_rowstride =*/ bitmap_get_rowstride,
        /*.get_width =*/ bitmap_get_width,
        /*.get_height =*/ bitmap_get_height,
        /*.get_bpp =*/ bitmap_get_bpp,
        /*.save =*/ bitmap_save,
        /*.modified =*/ bitmap_modified,
        /*.render =*/ bitmap_render,
};

struct gui_bitmap_table *beos_bitmap_table = &bitmap_table;