mapnik/src/text/renderer.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2015 Artem Pavlenko
 *
 * 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 2.1 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

// mapnik
#include <mapnik/text/renderer.hpp>
#include <mapnik/grid/grid.hpp>
#include <mapnik/text/text_properties.hpp>
#include <mapnik/font_engine_freetype.hpp>
#include <mapnik/text/face.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/image_any.hpp>

namespace mapnik
{

text_renderer::text_renderer (halo_rasterizer_e rasterizer, composite_mode_e comp_op,
                              composite_mode_e halo_comp_op, double scale_factor, stroker_ptr stroker)
    : rasterizer_(rasterizer),
      comp_op_(comp_op),
      halo_comp_op_(halo_comp_op),
      scale_factor_(scale_factor),
      glyphs_(),
      stroker_(stroker),
      transform_(),
      halo_transform_()
{}

void text_renderer::set_transform(agg::trans_affine const& transform)
{
    transform_ = transform;
}

void text_renderer::set_halo_transform(agg::trans_affine const& halo_transform)
{
    halo_transform_ = halo_transform;
}

void text_renderer::prepare_glyphs(glyph_positions const& positions)
{
    FT_Matrix matrix;
    FT_Vector pen;
    FT_Error  error;

    glyphs_.clear();
    glyphs_.reserve(positions.size());

    for (auto const& glyph_pos : positions)
    {
        glyph_info const& glyph = glyph_pos.glyph;
        glyph.face->set_character_sizes(glyph.format->text_size * scale_factor_); //TODO: Optimize this?

        matrix.xx = static_cast<FT_Fixed>( glyph_pos.rot.cos * 0x10000L);
        matrix.xy = static_cast<FT_Fixed>(-glyph_pos.rot.sin * 0x10000L);
        matrix.yx = static_cast<FT_Fixed>( glyph_pos.rot.sin * 0x10000L);
        matrix.yy = static_cast<FT_Fixed>( glyph_pos.rot.cos * 0x10000L);

        pixel_position pos = glyph_pos.pos + glyph.offset.rotate(glyph_pos.rot);
        pen.x = static_cast<FT_Pos>(pos.x * 64);
        pen.y = static_cast<FT_Pos>(pos.y * 64);

        FT_Face face = glyph.face->get_face();
        FT_Set_Transform(face, &matrix, &pen);

        error = FT_Load_Glyph(face, glyph.glyph_index, FT_LOAD_NO_HINTING);
        if (error) continue;

        FT_Glyph image;
        error = FT_Get_Glyph(face->glyph, &image);
        if (error) continue;

        glyphs_.emplace_back(image, *glyph.format);
    }
}

template <typename T>
void composite_bitmap(T & pixmap, FT_Bitmap *bitmap, unsigned rgba, int x, int y, double opacity, composite_mode_e comp_op)
{
    int x_max = x + bitmap->width;
    int y_max = y + bitmap->rows;

    for (int i = x, p = 0; i < x_max; ++i, ++p)
    {
        for (int j = y, q = 0; j < y_max; ++j, ++q)
        {
            unsigned gray=bitmap->buffer[q*bitmap->width+p];
            if (gray)
            {
                mapnik::composite_pixel(pixmap, comp_op, i, j, rgba, gray, opacity);
            }
        }
    }
}

template <typename T>
agg_text_renderer<T>::agg_text_renderer (pixmap_type & pixmap,
                                         halo_rasterizer_e rasterizer,
                                         composite_mode_e comp_op,
                                         composite_mode_e halo_comp_op,
                                         double scale_factor,
                                         stroker_ptr stroker)
    : text_renderer(rasterizer, comp_op, halo_comp_op, scale_factor, stroker), pixmap_(pixmap)
{}

template <typename T>
void agg_text_renderer<T>::render(glyph_positions const& pos)
{
    prepare_glyphs(pos);
    FT_Error  error;
    FT_Vector start;
    FT_Vector start_halo;
    int height = pixmap_.height();
    pixel_position const& base_point = pos.get_base_point();

    start.x =  static_cast<FT_Pos>(base_point.x * (1 << 6));
    start.y =  static_cast<FT_Pos>((height - base_point.y) * (1 << 6));
    start_halo = start;
    start.x += transform_.tx * 64;
    start.y += transform_.ty * 64;
    start_halo.x += halo_transform_.tx * 64;
    start_halo.y += halo_transform_.ty * 64;

    FT_Matrix halo_matrix;
    halo_matrix.xx = halo_transform_.sx  * 0x10000L;
    halo_matrix.xy = halo_transform_.shx * 0x10000L;
    halo_matrix.yy = halo_transform_.sy  * 0x10000L;
    halo_matrix.yx = halo_transform_.shy * 0x10000L;

    FT_Matrix matrix;
    matrix.xx = transform_.sx  * 0x10000L;
    matrix.xy = transform_.shx * 0x10000L;
    matrix.yy = transform_.sy  * 0x10000L;
    matrix.yx = transform_.shy * 0x10000L;

    // default formatting
    double halo_radius = 0;
    color black(0,0,0);
    unsigned fill = black.rgba();
    unsigned halo_fill = black.rgba();
    double text_opacity = 1.0;
    double halo_opacity = 1.0;

    for (auto const& glyph : glyphs_)
    {
        halo_fill = glyph.properties.halo_fill.rgba();
        halo_opacity = glyph.properties.halo_opacity;
        halo_radius = glyph.properties.halo_radius * scale_factor_;
        // make sure we've got reasonable values.
        if (halo_radius <= 0.0 || halo_radius > 1024.0) continue;
        FT_Glyph g;
        error = FT_Glyph_Copy(glyph.image, &g);
        if (!error)
        {
            FT_Glyph_Transform(g, &halo_matrix, &start_halo);
            if (rasterizer_ == HALO_RASTERIZER_FULL)
            {
                stroker_->init(halo_radius);
                FT_Glyph_Stroke(&g, stroker_->get(), 1);
                error = FT_Glyph_To_Bitmap(&g, FT_RENDER_MODE_NORMAL, 0, 1);
                if (!error)
                {
                    FT_BitmapGlyph bit = reinterpret_cast<FT_BitmapGlyph>(g);
                    composite_bitmap(pixmap_,
                                     &bit->bitmap,
                                     halo_fill,
                                     bit->left,
                                     height - bit->top,
                                     halo_opacity,
                                     halo_comp_op_);
                }
            }
            else
            {
                error = FT_Glyph_To_Bitmap(&g, FT_RENDER_MODE_NORMAL, 0, 1);
                if (!error)
                {
                    FT_BitmapGlyph bit = reinterpret_cast<FT_BitmapGlyph>(g);
                    render_halo(&bit->bitmap,
                                halo_fill,
                                bit->left,
                                height - bit->top,
                                halo_radius,
                                halo_opacity,
                                halo_comp_op_);
                }
            }
        }
        FT_Done_Glyph(g);
    }

    // render actual text
    for (auto & glyph : glyphs_)
    {
        fill = glyph.properties.fill.rgba();
        text_opacity = glyph.properties.text_opacity;
        FT_Glyph_Transform(glyph.image, &matrix, &start);
        error = FT_Glyph_To_Bitmap(&glyph.image ,FT_RENDER_MODE_NORMAL, 0, 1);
        if (!error)
        {
            FT_BitmapGlyph bit = reinterpret_cast<FT_BitmapGlyph>(glyph.image);
            composite_bitmap(pixmap_,
                             &bit->bitmap,
                             fill,
                             bit->left,
                             height - bit->top,
                             text_opacity,
                             comp_op_);
        }
        FT_Done_Glyph(glyph.image);
    }

}


template <typename T>
void grid_text_renderer<T>::render(glyph_positions const& pos, value_integer feature_id)
{
    prepare_glyphs(pos);
    FT_Error  error;
    FT_Vector start;
    unsigned height = pixmap_.height();
    pixel_position const& base_point = pos.get_base_point();
    start.x =  static_cast<FT_Pos>(base_point.x * (1 << 6));
    start.y =  static_cast<FT_Pos>((height - base_point.y) * (1 << 6));
    start.x += transform_.tx * 64;
    start.y += transform_.ty * 64;

    // now render transformed glyphs
    double halo_radius = 0.0;
    FT_Matrix halo_matrix;
    halo_matrix.xx = halo_transform_.sx  * 0x10000L;
    halo_matrix.xy = halo_transform_.shx * 0x10000L;
    halo_matrix.yy = halo_transform_.sy  * 0x10000L;
    halo_matrix.yx = halo_transform_.shy * 0x10000L;
    for (auto & glyph : glyphs_)
    {
        halo_radius = glyph.properties.halo_radius * scale_factor_;
        FT_Glyph_Transform(glyph.image, &halo_matrix, &start);
        error = FT_Glyph_To_Bitmap(&glyph.image, FT_RENDER_MODE_NORMAL, 0, 1);
        if (!error)
        {

            FT_BitmapGlyph bit = reinterpret_cast<FT_BitmapGlyph>(glyph.image);
            render_halo_id(&bit->bitmap,
                           feature_id,
                           bit->left,
                           height - bit->top,
                           static_cast<int>(halo_radius));
        }
        FT_Done_Glyph(glyph.image);
    }
}


template <typename T>
void agg_text_renderer<T>::render_halo(FT_Bitmap *bitmap,
                 unsigned rgba,
                 int x1,
                 int y1,
                 double halo_radius,
                 double opacity,
                 composite_mode_e comp_op)
{
    int width = bitmap->width;
    int height = bitmap->rows;
    int x, y;
    if (halo_radius < 1.0)
    {
        for (x=0; x < width; x++)
        {
            for (y=0; y < height; y++)
            {
                int gray = bitmap->buffer[y*bitmap->width+x];
                if (gray)
                {
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1-1, y+y1-1, rgba, gray*halo_radius*halo_radius, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1,   y+y1-1, rgba, gray*halo_radius, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1+1, y+y1-1, rgba, gray*halo_radius*halo_radius, opacity);

                    mapnik::composite_pixel(pixmap_, comp_op, x+x1-1, y+y1,   rgba, gray*halo_radius, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1,   y+y1,   rgba, gray, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1+1, y+y1,   rgba, gray*halo_radius, opacity);

                    mapnik::composite_pixel(pixmap_, comp_op, x+x1-1, y+y1+1, rgba, gray*halo_radius*halo_radius, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1,   y+y1+1, rgba, gray*halo_radius, opacity);
                    mapnik::composite_pixel(pixmap_, comp_op, x+x1+1, y+y1+1, rgba, gray*halo_radius*halo_radius, opacity);
                }
            }
        }
    }
    else
    {
        for (x=0; x < width; x++)
        {
            for (y=0; y < height; y++)
            {
                int gray = bitmap->buffer[y*bitmap->width+x];
                if (gray)
                {
                    for (int n=-halo_radius; n <=halo_radius; ++n)
                        for (int m=-halo_radius; m <= halo_radius; ++m)
                            mapnik::composite_pixel(pixmap_, comp_op, x+x1+m, y+y1+n, rgba, gray, opacity);
                }
            }
        }
    }
}

template <typename T>
void grid_text_renderer<T>::render_halo_id(
                    FT_Bitmap *bitmap,
                    mapnik::value_integer feature_id,
                    int x1,
                    int y1,
                    int halo_radius)
{
    int width = bitmap->width;
    int height = bitmap->rows;
    int x, y;
    for (x=0; x < width; x++)
    {
        for (y=0; y < height; y++)
        {
            int gray = bitmap->buffer[y*bitmap->width+x];
            if (gray)
            {
                for (int n=-halo_radius; n <=halo_radius; ++n)
                    for (int m=-halo_radius; m <= halo_radius; ++m)
                        pixmap_.setPixel(x+x1+m,y+y1+n,feature_id);
            }
        }
    }
}

template <typename T>
grid_text_renderer<T>::grid_text_renderer(pixmap_type &pixmap,
                                          composite_mode_e comp_op,
                                          double scale_factor)
    : text_renderer(HALO_RASTERIZER_FAST, comp_op, src_over, scale_factor),
      pixmap_(pixmap) {}

template class agg_text_renderer<image_rgba8>;
template class grid_text_renderer<grid>;

} // namespace mapnik