543 lines
17 KiB
C++
543 lines
17 KiB
C++
/*
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* state.cc
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*
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* track PDF states
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*
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* Copyright (C) 2012,2013 Lu Wang <coolwanglu@gmail.com>
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*/
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#include <cmath>
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#include <algorithm>
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#include "HTMLRenderer.h"
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#include "util/namespace.h"
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#include "util/math.h"
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namespace pdf2htmlEX {
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using std::max;
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using std::abs;
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void HTMLRenderer::updateAll(GfxState * state)
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{
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all_changed = true;
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updateTextPos(state);
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}
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void HTMLRenderer::updateRise(GfxState * state)
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{
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rise_changed = true;
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}
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void HTMLRenderer::updateTextPos(GfxState * state)
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{
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text_pos_changed = true;
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cur_tx = state->getLineX();
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cur_ty = state->getLineY();
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}
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void HTMLRenderer::updateTextShift(GfxState * state, double shift)
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{
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text_pos_changed = true;
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cur_tx -= shift * 0.001 * state->getFontSize() * state->getHorizScaling();
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}
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void HTMLRenderer::updateFont(GfxState * state)
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{
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font_changed = true;
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}
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void HTMLRenderer::updateCTM(GfxState * state, double m11, double m12, double m21, double m22, double m31, double m32)
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{
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ctm_changed = true;
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tracer.update_ctm(state, m11, m12, m21, m22, m31, m32);
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}
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void HTMLRenderer::updateTextMat(GfxState * state)
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{
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text_mat_changed = true;
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}
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void HTMLRenderer::updateHorizScaling(GfxState * state)
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{
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hori_scale_changed = true;
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}
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void HTMLRenderer::updateCharSpace(GfxState * state)
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{
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letter_space_changed = true;
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}
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void HTMLRenderer::updateWordSpace(GfxState * state)
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{
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word_space_changed = true;
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}
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void HTMLRenderer::updateRender(GfxState * state)
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{
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// currently Render is traced for color only
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// might need something like render_changed later
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fill_color_changed = true;
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stroke_color_changed = true;
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}
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void HTMLRenderer::updateFillColorSpace(GfxState * state)
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{
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fill_color_changed = true;
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}
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void HTMLRenderer::updateStrokeColorSpace(GfxState * state)
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{
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stroke_color_changed = true;
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}
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void HTMLRenderer::updateFillColor(GfxState * state)
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{
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fill_color_changed = true;
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}
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void HTMLRenderer::updateStrokeColor(GfxState * state)
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{
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stroke_color_changed = true;
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}
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void HTMLRenderer::clip(GfxState * state)
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{
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clip_changed = true;
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tracer.clip(state);
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}
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void HTMLRenderer::eoClip(GfxState * state)
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{
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clip_changed = true;
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tracer.clip(state, true);
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}
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void HTMLRenderer::clipToStrokePath(GfxState * state)
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{
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clip_changed = true;
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tracer.clip_to_stroke_path(state);
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}
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void HTMLRenderer::reset_state()
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{
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inTransparencyGroup = 0;
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draw_text_scale = 1.0;
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cur_font_size = 0.0;
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memcpy(cur_text_tm, ID_MATRIX, sizeof(cur_text_tm));
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// reset html_state
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cur_text_state.font_info = install_font(nullptr);
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cur_text_state.font_size = 0;
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cur_text_state.fill_color.transparent = true;
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cur_text_state.stroke_color.transparent = true;
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cur_text_state.letter_space = 0;
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cur_text_state.word_space = 0;
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cur_text_state.vertical_align = 0;
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cur_line_state.x = 0;
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cur_line_state.y = 0;
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memcpy(cur_line_state.transform_matrix, ID_MATRIX, sizeof(cur_line_state.transform_matrix));
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cur_line_state.is_char_covered = [this](int index) { return is_char_covered(index);};
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cur_clip_state.xmin = 0;
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cur_clip_state.xmax = 0;
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cur_clip_state.ymin = 0;
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cur_clip_state.ymax = 0;
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cur_tx = cur_ty = 0;
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draw_tx = draw_ty = 0;
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reset_state_change();
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all_changed = true;
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}
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void HTMLRenderer::reset_state_change()
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{
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all_changed = false;
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rise_changed = false;
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text_pos_changed = false;
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font_changed = false;
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ctm_changed = false;
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text_mat_changed = false;
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hori_scale_changed = false;
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letter_space_changed = false;
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word_space_changed = false;
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fill_color_changed = false;
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stroke_color_changed = false;
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clip_changed = false;
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}
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template<class NewLineState>
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void set_line_state(NewLineState & cur_ls, NewLineState new_ls)
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{
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if(new_ls > cur_ls)
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cur_ls = new_ls;
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}
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void HTMLRenderer::check_state_change(GfxState * state)
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{
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// DEPENDENCY WARNING
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// don't adjust the order of state checking
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new_line_state = NLS_NONE;
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if(all_changed || clip_changed)
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{
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HTMLClipState new_clip_state;
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state->getClipBBox(&new_clip_state.xmin, &new_clip_state.ymin, &new_clip_state.xmax, &new_clip_state.ymax);
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if(!(equal(cur_clip_state.xmin, new_clip_state.xmin)
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&& equal(cur_clip_state.xmax, new_clip_state.xmax)
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&& equal(cur_clip_state.ymin, new_clip_state.ymin)
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&& equal(cur_clip_state.ymax, new_clip_state.ymax)))
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{
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cur_clip_state = new_clip_state;
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set_line_state(new_line_state, NLS_NEWCLIP);
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}
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}
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bool need_recheck_position = false;
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bool need_rescale_font = false;
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bool draw_text_scale_changed = false;
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// save current info for later use
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auto old_text_state = cur_text_state;
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auto old_line_state = cur_line_state;
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double old_tm[6];
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memcpy(old_tm, cur_text_tm, sizeof(old_tm));
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double old_draw_text_scale = draw_text_scale;
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// text position
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// we've been tracking the text position positively in the update*** functions
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if(all_changed || text_pos_changed)
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{
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need_recheck_position = true;
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}
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// font name & size
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if(all_changed || font_changed)
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{
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const FontInfo * new_font_info = install_font(state->getFont().get());
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if(!(new_font_info->id == cur_text_state.font_info->id))
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{
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// The width of the type 3 font text, if shown, is likely to be wrong
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// So we will create separate (absolute positioned) blocks for them, such that it won't affect other text
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if((new_font_info->is_type3 || cur_text_state.font_info->is_type3) && (!param.process_type3))
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{
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set_line_state(new_line_state, NLS_NEWLINE);
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}
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else
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{
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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cur_text_state.font_info = new_font_info;
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}
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/*
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* For Type 3 fonts, we need to take type3_font_size_scale into consideration
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*/
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if((new_font_info->is_type3 || cur_text_state.font_info->is_type3) && param.process_type3)
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need_rescale_font = true;
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double new_font_size = state->getFontSize();
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if(!equal(cur_font_size, new_font_size))
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{
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need_rescale_font = true;
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cur_font_size = new_font_size;
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}
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}
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// ctm & text ctm & hori scale & rise
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if(all_changed || ctm_changed || text_mat_changed || hori_scale_changed || rise_changed)
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{
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double new_text_tm[6];
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double m1[6];
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double m2[6];
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//the matrix with horizontal_scale and rise
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m1[0] = state->getHorizScaling();
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m1[3] = 1;
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m1[5] = state->getRise();
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m1[1] = m1[2] = m1[4] = 0;
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tm_multiply(m2, state->getCTM(), state->getTextMat());
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tm_multiply(new_text_tm, m2, m1);
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if(!tm_equal(new_text_tm, cur_text_tm))
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{
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need_recheck_position = true;
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need_rescale_font = true;
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memcpy(cur_text_tm, new_text_tm, sizeof(cur_text_tm));
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}
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}
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// draw_text_tm, draw_text_scale
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// depends: font size & ctm & text_ctm & hori scale & rise
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if(need_rescale_font)
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{
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/*
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* Rescale the font
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* If the font-size is 1, and the matrix is [10,0,0,10,0,0], we would like to change it to
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* font-size == 10 and matrix == [1,0,0,1,0,0],
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* such that it will be easy and natural for web browsers
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*/
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double new_draw_text_tm[6];
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memcpy(new_draw_text_tm, cur_text_tm, sizeof(new_draw_text_tm));
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// see how the tm (together with text_scale_factor2) would change the vector (0,1)
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double new_draw_text_scale = 1.0/text_scale_factor2 * hypot(new_draw_text_tm[2], new_draw_text_tm[3]);
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double new_draw_font_size = cur_font_size;
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if(is_positive(new_draw_text_scale))
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{
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// scale both font size and matrix
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new_draw_font_size *= new_draw_text_scale;
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for(int i = 0; i < 4; ++i)
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new_draw_text_tm[i] /= new_draw_text_scale;
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}
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else
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{
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new_draw_text_scale = 1.0;
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}
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if(is_positive(-new_draw_font_size))
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{
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// CSS cannot handle flipped pages
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new_draw_font_size *= -1;
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for(int i = 0; i < 4; ++i)
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new_draw_text_tm[i] *= -1;
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}
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if(!(equal(new_draw_text_scale, draw_text_scale)))
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{
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draw_text_scale_changed = true;
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draw_text_scale = new_draw_text_scale;
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}
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if(!equal(new_draw_font_size, cur_text_state.font_size))
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{
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set_line_state(new_line_state, NLS_NEWSTATE);
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cur_text_state.font_size = new_draw_font_size;
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}
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if(!tm_equal(new_draw_text_tm, cur_line_state.transform_matrix, 4))
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{
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set_line_state(new_line_state, NLS_NEWLINE);
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memcpy(cur_line_state.transform_matrix, new_draw_text_tm, sizeof(cur_line_state.transform_matrix));
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}
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}
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// see if the new line is compatible with the current line with proper position shift
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// don't bother doing the heavy job when (new_line_state == NLS_NEWLINE)
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// depends: text position & transformation
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if(need_recheck_position && (new_line_state < NLS_NEWLINE))
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{
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// TM[4] and/or TM[5] have been changed
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// To find an offset (dx,dy), which would cancel the effect
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/*
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* CurTM * (cur_tx, cur_ty, 1)^T = OldTM * (draw_tx + dx, draw_ty + dy, 1)^T
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*
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* the first 4 elements of CurTM and OldTM should be the proportional
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* otherwise the following text cannot be parallel
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*
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* NOTE:
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* dx,dy are handled by the old state. so they should be multiplied by old_draw_text_scale
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*/
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bool merged = false;
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double dx = 0;
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double dy = 0;
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if(tm_equal(old_line_state.transform_matrix, cur_line_state.transform_matrix, 4))
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{
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double det = old_tm[0] * old_tm[3] - old_tm[1] * old_tm[2];
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if(!equal(det, 0))
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{
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double lhs1 = cur_text_tm[0] * cur_tx + cur_text_tm[2] * cur_ty + cur_text_tm[4] - old_tm[0] * draw_tx - old_tm[2] * draw_ty - old_tm[4];
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double lhs2 = cur_text_tm[1] * cur_tx + cur_text_tm[3] * cur_ty + cur_text_tm[5] - old_tm[1] * draw_tx - old_tm[3] * draw_ty - old_tm[5];
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/*
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* Now the equation system becomes
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*
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* lhs1 = OldTM[0] * dx + OldTM[2] * dy
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* lhs2 = OldTM[1] * dx + OldTM[3] * dy
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*/
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double inverted[4];
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inverted[0] = old_tm[3] / det;
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inverted[1] = -old_tm[1] / det;
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inverted[2] = -old_tm[2] / det;
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inverted[3] = old_tm[0] / det;
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dx = inverted[0] * lhs1 + inverted[2] * lhs2;
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dy = inverted[1] * lhs1 + inverted[3] * lhs2;
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if(equal(dy, 0))
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{
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// text on a same horizontal line, we can insert positive or negative x-offsets
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merged = true;
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}
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else if(param.optimize_text)
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{
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// otherwise we merge the lines only when
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// - text are not shifted to the left too much
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// - text are not moved too high or too low
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if((dx * old_draw_text_scale) >= -param.space_threshold * old_text_state.em_size() - EPS)
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{
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double oldymin = old_text_state.font_info->descent * old_text_state.font_size;
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double oldymax = old_text_state.font_info->ascent * old_text_state.font_size;
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double ymin = dy * old_draw_text_scale + cur_text_state.font_info->descent * cur_text_state.font_size;
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double ymax = dy * old_draw_text_scale + cur_text_state.font_info->ascent * cur_text_state.font_size;
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if((ymin <= oldymax + EPS) && (ymax >= oldymin - EPS))
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{
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merged = true;
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}
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}
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}
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}
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//else no solution
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}
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// else: different rotation: force new line
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if(merged && !equal(state->getHorizScaling(), 0))
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{
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html_text_page.get_cur_line()->append_offset(dx * old_draw_text_scale / state->getHorizScaling());
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if(equal(dy, 0))
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{
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cur_text_state.vertical_align = 0;
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}
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else
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{
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cur_text_state.vertical_align = (dy * old_draw_text_scale);
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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draw_tx = cur_tx;
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draw_ty = cur_ty;
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}
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else
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{
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set_line_state(new_line_state, NLS_NEWLINE);
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}
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}
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else
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{
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// no vertical shift if no need to check position
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cur_text_state.vertical_align = 0;
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}
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// letter space
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// depends: draw_text_scale
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if(all_changed || letter_space_changed || draw_text_scale_changed)
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{
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double new_letter_space = state->getCharSpace() * draw_text_scale;
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if(!equal(new_letter_space, cur_text_state.letter_space))
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{
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cur_text_state.letter_space = new_letter_space;
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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}
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// word space
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// depends draw_text_scale
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if(all_changed || word_space_changed || draw_text_scale_changed)
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{
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double new_word_space = state->getWordSpace() * draw_text_scale;
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if(!equal(new_word_space, cur_text_state.word_space))
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{
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cur_text_state.word_space = new_word_space;
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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}
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// fill color
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if((!(param.fallback)) && (all_changed || fill_color_changed))
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{
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// * PDF Spec. Table 106 –Text rendering modes
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static const char FILL[8] = { true, false, true, false, true, false, true, false };
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int idx = state->getRender();
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assert((idx >= 0) && (idx < 8));
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Color new_fill_color;
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if(FILL[idx])
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{
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new_fill_color.transparent = false;
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state->getFillRGB(&new_fill_color.rgb);
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}
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else
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{
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new_fill_color.transparent = true;
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}
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if(!(new_fill_color == cur_text_state.fill_color))
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{
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cur_text_state.fill_color = new_fill_color;
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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}
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// stroke color
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if((!(param.fallback)) && (all_changed || stroke_color_changed))
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{
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// * PDF Spec. Table 106 – Text rendering modes
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static const char STROKE[8] = { false, true, true, false, false, true, true, false };
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int idx = state->getRender();
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assert((idx >= 0) && (idx < 8));
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Color new_stroke_color;
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// stroke
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if(STROKE[idx])
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{
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new_stroke_color.transparent = false;
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state->getStrokeRGB(&new_stroke_color.rgb);
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}
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else
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{
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new_stroke_color.transparent = true;
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}
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if(!(new_stroke_color == cur_text_state.stroke_color))
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{
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cur_text_state.stroke_color = new_stroke_color;
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set_line_state(new_line_state, NLS_NEWSTATE);
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}
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}
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reset_state_change();
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}
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void HTMLRenderer::prepare_text_line(GfxState * state)
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{
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if(!(html_text_page.get_cur_line()))
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new_line_state = NLS_NEWCLIP;
|
||
|
||
if(new_line_state >= NLS_NEWCLIP)
|
||
{
|
||
html_text_page.clip(cur_clip_state);
|
||
}
|
||
|
||
if(new_line_state >= NLS_NEWLINE)
|
||
{
|
||
// update position such that they will be recorded by text_line_buf
|
||
double rise_x, rise_y;
|
||
state->textTransformDelta(0, state->getRise(), &rise_x, &rise_y);
|
||
state->transform(state->getCurX() + rise_x, state->getCurY() + rise_y, &cur_line_state.x, &cur_line_state.y);
|
||
|
||
if (param.correct_text_visibility)
|
||
cur_line_state.first_char_index = get_char_count();
|
||
|
||
html_text_page.open_new_line(cur_line_state);
|
||
|
||
cur_text_state.vertical_align = 0;
|
||
|
||
//resync position
|
||
draw_ty = cur_ty;
|
||
draw_tx = cur_tx;
|
||
}
|
||
else
|
||
{
|
||
// align horizontal position
|
||
// try to merge with the last line if possible
|
||
double target = (cur_tx - draw_tx) * draw_text_scale;
|
||
if(!equal(target, 0))
|
||
{
|
||
html_text_page.get_cur_line()->append_offset(target);
|
||
draw_tx += target / draw_text_scale;
|
||
}
|
||
}
|
||
|
||
if(new_line_state != NLS_NONE)
|
||
{
|
||
html_text_page.get_cur_line()->append_state(cur_text_state);
|
||
}
|
||
}
|
||
|
||
} //namespace pdf2htmlEX
|