path: root/src/extension/internal/cairo-renderer.cpp

#define __SP_CAIRO_RENDERER_C__

/** \file
 * Rendering with Cairo.
 */
/*
 * Author:
 *   Miklos Erdelyi <erdelyim@gmail.com>
 *
 * Copyright (C) 2006 Miklos Erdelyi
 * 
 * Licensed under GNU GPL
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_CAIRO_PDF

#ifndef PANGO_ENABLE_BACKEND
#define PANGO_ENABLE_BACKEND
#endif

#ifndef PANGO_ENABLE_ENGINE
#define PANGO_ENABLE_ENGINE
#endif


#include <signal.h>
#include <errno.h>

#include <libnr/n-art-bpath.h>
#include <libnr/nr-matrix-ops.h>
#include <libnr/nr-matrix-fns.h>
#include <libnr/nr-matrix-translate-ops.h>
#include <libnr/nr-scale-matrix-ops.h>

#include <glib/gmem.h>

#include <glibmm/i18n.h>
#include "display/nr-arena.h"
#include "display/nr-arena-item.h"
#include "display/nr-arena-group.h"
#include "display/curve.h"
#include "display/canvas-bpath.h"
#include "sp-item.h"
#include "sp-item-group.h"
#include "marker-status.h"
#include "style.h"
#include "sp-marker.h"
#include "sp-linear-gradient.h"
#include "sp-radial-gradient.h"
#include "sp-root.h"
#include "sp-shape.h"
#include "sp-use.h"
#include "sp-text.h"
#include "sp-flowtext.h"
#include "sp-image.h"
#include "sp-symbol.h"
#include "sp-pattern.h"
#include "sp-mask.h"
#include "sp-clippath.h"

#include <unit-constants.h>

#include "cairo-renderer.h"
#include "cairo-render-context.h"
#include "extension/system.h"

#include "io/sys.h"

#include <cairo.h>

// include support for only the compiled-in surface types
#ifdef CAIRO_HAS_PDF_SURFACE
#include <cairo-pdf.h>
#endif
#ifdef CAIRO_HAS_PS_SURFACE
#include <cairo-ps.h>
#endif

//#define TRACE(_args) g_printf _args
#define TRACE(_args)

// FIXME: expose these from sp-clippath/mask.cpp
struct SPClipPathView {
    SPClipPathView *next;
    unsigned int key;
    NRArenaItem *arenaitem;
    NRRect bbox;
};

struct SPMaskView {
    SPMaskView *next;
    unsigned int key;
    NRArenaItem *arenaitem;
    NRRect bbox;
};

namespace Inkscape {
namespace Extension {
namespace Internal {

CairoRenderer::CairoRenderer(void)
{}

CairoRenderer::~CairoRenderer(void)
{
    /* restore default signal handling for SIGPIPE */
#if !defined(_WIN32) && !defined(__WIN32__)
    (void) signal(SIGPIPE, SIG_DFL);
#endif

    return;
}

CairoRenderContext*
CairoRenderer::createContext(void)
{
    CairoRenderContext *new_context = new CairoRenderContext(this);
    g_assert( new_context != NULL );

    new_context->_state_stack = NULL;
    new_context->_state = NULL;

    // create initial render state
    CairoRenderState *state = new_context->_createState();
    nr_matrix_set_identity(&state->transform);
    new_context->_state_stack = g_slist_prepend(new_context->_state_stack, state);
    new_context->_state = state;

    return new_context;
}

void
CairoRenderer::destroyContext(CairoRenderContext *ctx)
{
    delete ctx;    
}

/*

Here comes the rendering part which could be put into the 'render' methods of SPItems'

*/

/* The below functions are copy&pasted plus slightly modified from *_invoke_print functions. */
static void sp_item_invoke_render(SPItem *item, CairoRenderContext *ctx);
static void sp_group_render(SPItem *item, CairoRenderContext *ctx);
static void sp_use_render(SPItem *item, CairoRenderContext *ctx);
static void sp_shape_render(SPItem *item, CairoRenderContext *ctx);
static void sp_text_render(SPItem *item, CairoRenderContext *ctx);
static void sp_flowtext_render(SPItem *item, CairoRenderContext *ctx);
static void sp_image_render(SPItem *item, CairoRenderContext *ctx);
static void sp_symbol_render(SPItem *item, CairoRenderContext *ctx);

static void sp_shape_render (SPItem *item, CairoRenderContext *ctx)
{
    NRRect pbox;

    SPShape *shape = SP_SHAPE(item);

    if (!shape->curve) return;

    /* fixme: Think (Lauris) */
    sp_item_invoke_bbox(item, &pbox, NR::identity(), TRUE);
    NR::Matrix const i2d = sp_item_i2d_affine(item);

    SPStyle* style = SP_OBJECT_STYLE (item);
    CairoRenderer *renderer = ctx->getRenderer();

    NRBPath bp;
    bp.path = SP_CURVE_BPATH(shape->curve);

    ctx->renderPath(&bp, style, &pbox);

    for (NArtBpath* bp = SP_CURVE_BPATH(shape->curve); bp->code != NR_END; bp++) {
        for (int m = SP_MARKER_LOC_START; m < SP_MARKER_LOC_QTY; m++) {
            if (sp_shape_marker_required (shape, m, bp)) {

                SPMarker* marker = SP_MARKER (shape->marker[m]);
                SPItem* marker_item = sp_item_first_item_child (SP_OBJECT (shape->marker[m]));

                NR::Matrix tr(sp_shape_marker_get_transform(shape, bp));

                if (marker->markerUnits == SP_MARKER_UNITS_STROKEWIDTH) {
                    tr = NR::scale(style->stroke_width.computed) * tr;
                }

                tr = marker_item->transform * marker->c2p * tr;

                NR::Matrix old_tr = marker_item->transform;
                marker_item->transform = tr;
                renderer->renderItem (ctx, marker_item);
                marker_item->transform = old_tr;
            }
        }
    }
}

static void sp_group_render(SPItem *item, CairoRenderContext *ctx)
{
    SPGroup *group = SP_GROUP(item);
    CairoRenderer *renderer = ctx->getRenderer();
    TRACE(("group op: %f\n", SP_SCALE24_TO_FLOAT(SP_OBJECT_STYLE(item)->opacity.value)));
    
    GSList *l = g_slist_reverse(group->childList(false));
    while (l) {
        SPObject *o = SP_OBJECT (l->data);
        if (SP_IS_ITEM(o)) {
            renderer->renderItem (ctx, SP_ITEM (o));
        }        
        l = g_slist_remove (l, o);
    }
}

static void sp_use_render(SPItem *item, CairoRenderContext *ctx)
{
    bool translated = false;
    NRMatrix tp;
    SPUse *use = SP_USE(item);
    CairoRenderer *renderer = ctx->getRenderer();

    if ((use->x._set && use->x.computed != 0) || (use->y._set && use->y.computed != 0)) {
        nr_matrix_set_translate(&tp, use->x.computed, use->y.computed);
        ctx->pushState();
        ctx->transform(&tp);
        translated = true;
    }

    if (use->child && SP_IS_ITEM(use->child)) {
        renderer->renderItem(ctx, SP_ITEM(use->child));
    }

    if (translated) {
        ctx->popState();
    }
}

static void sp_text_render(SPItem *item, CairoRenderContext *ctx)
{
    SPText *group = SP_TEXT (item);
    group->layout.showGlyphs(ctx);
}

static void sp_flowtext_render(SPItem *item, CairoRenderContext *ctx)
{
    SPFlowtext *group = SP_FLOWTEXT(item);
    group->layout.showGlyphs(ctx);
}

static void sp_image_render(SPItem *item, CairoRenderContext *ctx)
{
    SPImage *image;
    NRMatrix tp, s, t;
    guchar *px;
    int w, h, rs;

    image = SP_IMAGE (item);

    if (!image->pixbuf) return;
    if ((image->width.computed <= 0.0) || (image->height.computed <= 0.0)) return;

    px = gdk_pixbuf_get_pixels (image->pixbuf);
    w = gdk_pixbuf_get_width (image->pixbuf);
    h = gdk_pixbuf_get_height (image->pixbuf);
    rs = gdk_pixbuf_get_rowstride (image->pixbuf);

    double x = image->x.computed;
    double y = image->y.computed;
    double width = image->width.computed;
    double height = image->height.computed;

    if (image->aspect_align != SP_ASPECT_NONE) {
        calculatePreserveAspectRatio (image->aspect_align, image->aspect_clip, (double)w, (double)h,
                                                     &x, &y, &width, &height);
    }
    
    if (image->aspect_clip == SP_ASPECT_SLICE && !ctx->getCurrentState()->has_overflow) {
        ctx->addClippingRect(image->x.computed, image->y.computed, image->width.computed, image->height.computed);
    }

    nr_matrix_set_translate (&tp, x, y);    
    nr_matrix_set_scale (&s, width / (double)w, height / (double)h);
    nr_matrix_multiply (&t, &s, &tp);

    ctx->renderImage (px, w, h, rs, &t, SP_OBJECT_STYLE (item));
}

static void sp_symbol_render(SPItem *item, CairoRenderContext *ctx)
{
    SPSymbol *symbol = SP_SYMBOL(item);
    if (!SP_OBJECT_IS_CLONED (symbol))
        return;
    
    /* Cloned <symbol> is actually renderable */
    ctx->pushState();
    ctx->transform(&symbol->c2p);
        
    // apply viewbox if set
    if (0 /*symbol->viewBox_set*/) {
        NRMatrix vb2user;
        double x, y, width, height;
        double view_width, view_height;
        x = 0.0;
        y = 0.0;
        width = 1.0;
        height = 1.0;
        
        view_width = symbol->viewBox.x1 - symbol->viewBox.x0;
        view_height = symbol->viewBox.y1 - symbol->viewBox.y0;
        
        calculatePreserveAspectRatio(symbol->aspect_align, symbol->aspect_clip, view_width, view_height,
                                     &x, &y,&width, &height);

        // [itemTransform *] translate(x, y) * scale(w/vw, h/vh) * translate(-vx, -vy);
        nr_matrix_set_identity(&vb2user);
        vb2user[0] = width / view_width;
        vb2user[3] = height / view_height;
        vb2user[4] = x - symbol->viewBox.x0 * vb2user[0];
        vb2user[5] = y - symbol->viewBox.y0 * vb2user[3];

        ctx->transform(&vb2user);
    }
    
    sp_group_render(item, ctx);
    ctx->popState();
}

static void sp_root_render(SPItem *item, CairoRenderContext *ctx)
{
    SPRoot *root = SP_ROOT(item);
    CairoRenderer *renderer = ctx->getRenderer();

    if (!ctx->getCurrentState()->has_overflow && SP_OBJECT(item)->parent)
        ctx->addClippingRect(root->x.computed, root->y.computed, root->width.computed, root->height.computed);

    ctx->pushState();
    renderer->setStateForItem(ctx, item);
    ctx->transform(root->c2p);
    sp_group_render(item, ctx);
    ctx->popState();
}

static void sp_item_invoke_render(SPItem *item, CairoRenderContext *ctx)
{
    if (SP_IS_ROOT(item)) {
        TRACE(("root\n"));
        return sp_root_render(item, ctx);
    } else if (SP_IS_GROUP(item)) {
        TRACE(("group\n"));
        return sp_group_render(item, ctx);
    } else if (SP_IS_SHAPE(item)) {
        TRACE(("shape\n"));
        return sp_shape_render(item, ctx);
    } else if (SP_IS_USE(item)) {
        TRACE(("use begin---\n"));
        sp_use_render(item, ctx);
        TRACE(("---use end\n"));
    } else if (SP_IS_SYMBOL(item)) {
        TRACE(("symbol\n"));
        return sp_symbol_render(item, ctx);
    } else if (SP_IS_TEXT(item)) {
        TRACE(("text\n"));
        return sp_text_render(item, ctx);
    } else if (SP_IS_FLOWTEXT(item)) {
        TRACE(("flowtext\n"));
        return sp_flowtext_render(item, ctx);
    } else if (SP_IS_IMAGE(item)) {
        TRACE(("image\n"));
        return sp_image_render(item, ctx);
    }
}

void
CairoRenderer::setStateForItem(CairoRenderContext *ctx, SPItem const *item)
{
    SPStyle const *style = SP_OBJECT_STYLE(item);
    ctx->setStateForStyle(style);
    
    CairoRenderState *state = ctx->getCurrentState();
    state->clip_path = item->clip_ref->getObject();
    state->mask = item->mask_ref->getObject();

    // If parent_has_userspace is true the parent state's transform
    // has to be used for the mask's/clippath's context.
    // This is so because we use the image's/(flow)text's transform for positioning
    // instead of explicitly specifying it and letting the renderer do the
    // transformation before rendering the item.
    if (SP_IS_TEXT(item) || SP_IS_FLOWTEXT(item) || SP_IS_IMAGE(item))
        state->parent_has_userspace = TRUE;
    TRACE(("set op: %f\n", state->opacity));
}

void
CairoRenderer::renderItem(CairoRenderContext *ctx, SPItem *item)
{
    ctx->pushState();
    setStateForItem(ctx, item);
    
    CairoRenderState *state = ctx->getCurrentState();
    state->need_layer = ( state->mask || state->clip_path || state->opacity != 1.0 );

    if (state->need_layer) {
        state->merge_opacity = FALSE;
        ctx->pushLayer();
    }
    ctx->transform(item->transform);
    sp_item_invoke_render(item, ctx);

    if (state->need_layer)
        ctx->popLayer();

    ctx->popState();
}

bool
CairoRenderer::setupDocument(CairoRenderContext *ctx, SPDocument *doc)
{
    g_assert( ctx != NULL );

    if (ctx->_vector_based_target) {
        // width and height in pt
        ctx->_width = sp_document_width(doc) * PT_PER_PX;
        ctx->_height = sp_document_height(doc) * PT_PER_PX;
    } else {
        ctx->_width = sp_document_width(doc);
        ctx->_height = sp_document_height(doc);
    }

    NRRect d;
    bool pageBoundingBox = true;
    if (pageBoundingBox) {
        d.x0 = d.y0 = 0;
        d.x1 = ceil(ctx->_width);
        d.y1 = ceil(ctx->_height);
    } else {
        SPItem* doc_item = SP_ITEM(sp_document_root(doc));
        sp_item_invoke_bbox(doc_item, &d, sp_item_i2r_affine(doc_item), TRUE);
        if (ctx->_vector_based_target) {
            // convert from px to pt
            d.x0 *= PT_PER_PX;
            d.x1 *= PT_PER_PX;
            d.y0 *= PT_PER_PX;
            d.y1 *= PT_PER_PX;
        }
    }
    TRACE(("%f x %f\n", ctx->_width, ctx->_height));
    
    return ctx->setupSurface(d.x1-d.x0, d.y1-d.y0);
}

#include "macros.h" // SP_PRINT_*

void
CairoRenderer::applyClipPath(CairoRenderContext *ctx, SPClipPath const *cp)
{
    g_assert( ctx != NULL && ctx->_is_valid );
        
    if (cp == NULL)
        return;
    
    CairoRenderContext::CairoRenderMode saved_mode = ctx->getRenderMode();
    ctx->setRenderMode(CairoRenderContext::RENDER_MODE_CLIP);

    NRMatrix saved_ctm;
    if (cp->clipPathUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX) {
        NRMatrix t;
        //SP_PRINT_DRECT("clipd", cp->display->bbox);
        NRRect clip_bbox(cp->display->bbox);
        nr_matrix_set_scale(&t, clip_bbox.x1 - clip_bbox.x0, clip_bbox.y1 - clip_bbox.y0);
        t.c[4] = clip_bbox.x0;
        t.c[5] = clip_bbox.y0;
        nr_matrix_multiply(&t, &t, &ctx->getCurrentState()->transform);
        ctx->getTransform(&saved_ctm);
        ctx->setTransform(&t);
    }

    TRACE(("BEGIN clip\n"));
    SPObject *co = SP_OBJECT(cp);
    for (SPObject *child = sp_object_first_child(co) ; child != NULL; child = SP_OBJECT_NEXT(child) ) {
        if (SP_IS_ITEM(child)) {
            SPItem *item = SP_ITEM(child);
            renderItem(ctx, item);
        }
    }
    TRACE(("END clip\n"));

    // do clipping only if this was the first call to applyClipPath
    if (ctx->getClipMode() == CairoRenderContext::CLIP_MODE_PATH
        && saved_mode == CairoRenderContext::RENDER_MODE_NORMAL)
        cairo_clip(ctx->_cr);

    if (cp->clipPathUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX)
        ctx->setTransform(&saved_ctm);

    ctx->setRenderMode(saved_mode);
}

void
CairoRenderer::applyMask(CairoRenderContext *ctx, SPMask const *mask)
{
    g_assert( ctx != NULL && ctx->_is_valid );
        
    if (mask == NULL)
        return;

    //SP_PRINT_DRECT("maskd", &mask->display->bbox);
    NRRect mask_bbox(mask->display->bbox);
    // TODO: should the bbox be transformed if maskUnits != userSpaceOnUse ?
    if (mask->maskContentUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX) {
        NRMatrix t;
        nr_matrix_set_scale(&t, mask_bbox.x1 - mask_bbox.x0, mask_bbox.y1 - mask_bbox.y0);
        t.c[4] = mask_bbox.x0;
        t.c[5] = mask_bbox.y0;
        nr_matrix_multiply(&t, &t, &ctx->getCurrentState()->transform);
        ctx->setTransform(&t);
    }

    // clip mask contents
    ctx->addClippingRect(mask_bbox.x0, mask_bbox.y0, mask_bbox.x1 - mask_bbox.x0, mask_bbox.y1 - mask_bbox.y0);

    ctx->pushState();

    TRACE(("BEGIN mask\n"));
    SPObject *co = SP_OBJECT(mask);
    for (SPObject *child = sp_object_first_child(co) ; child != NULL; child = SP_OBJECT_NEXT(child) ) {
        if (SP_IS_ITEM(child)) {
            SPItem *item = SP_ITEM(child);
            renderItem(ctx, item);
        }
    }
    TRACE(("END mask\n"));

    ctx->popState();
}

void
calculatePreserveAspectRatio(unsigned int aspect_align, unsigned int aspect_clip, double vp_width, double vp_height,
                             double *x, double *y, double *width, double *height)
{
    if (aspect_align == SP_ASPECT_NONE)
        return;
        
    double scalex, scaley, scale;
    double new_width, new_height;
    scalex = *width / vp_width;
    scaley = *height / vp_height;
    scale = (aspect_clip == SP_ASPECT_MEET) ? MIN(scalex, scaley) : MAX(scalex, scaley);
    new_width = vp_width * scale;
    new_height = vp_height * scale;
    /* Now place viewbox to requested position */
    switch (aspect_align) {
        case SP_ASPECT_XMIN_YMIN:
            break;
        case SP_ASPECT_XMID_YMIN:
            *x -= 0.5 * (new_width - *width);
            break;
        case SP_ASPECT_XMAX_YMIN:
            *x -= 1.0 * (new_width - *width);
            break;
        case SP_ASPECT_XMIN_YMID:
            *y -= 0.5 * (new_height - *height);
            break;
        case SP_ASPECT_XMID_YMID:
            *x -= 0.5 * (new_width - *width);
            *y -= 0.5 * (new_height - *height);
            break;
        case SP_ASPECT_XMAX_YMID:
            *x -= 1.0 * (new_width - *width);
            *y -= 0.5 * (new_height - *height);
            break;
        case SP_ASPECT_XMIN_YMAX:
            *y -= 1.0 * (new_height - *height);
            break;
        case SP_ASPECT_XMID_YMAX:
            *x -= 0.5 * (new_width - *width);
            *y -= 1.0 * (new_height - *height);
            break;
        case SP_ASPECT_XMAX_YMAX:
            *x -= 1.0 * (new_width - *width);
            *y -= 1.0 * (new_height - *height);
            break;
        default:
            break;
    }
    *width = new_width;
    *height = new_height;
}

#include "clear-n_.h"

}  /* namespace Internal */
}  /* namespace Extension */
}  /* namespace Inkscape */

#undef TRACE

/* End of GNU GPL code */

#endif /* HAVE_CAIRO_PDF */


/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :