mirror of
https://github.com/pdf2htmlEX/pdf2htmlEX.git
synced 2024-10-06 12:01:39 +00:00
470 lines
13 KiB
C++
470 lines
13 KiB
C++
/*
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* state.cc
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*
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* track current state
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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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/*
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* TODO
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* optimize lines using nested <span> (reuse classes)
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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 "TextLineBuffer.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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}
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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::reset_state()
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{
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draw_text_scale = 1.0;
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cur_font_info = install_font(nullptr);
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cur_font_size = 0.0;
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font_size_manager.reset();
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memcpy(cur_text_tm, ID_MATRIX, sizeof(cur_text_tm));
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memcpy(draw_text_tm, ID_MATRIX, sizeof(draw_text_tm));
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cur_ttm_id = install_transform_matrix(draw_text_tm);
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letter_space_manager.reset();
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word_space_manager .reset();
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cur_fill_color.r = cur_fill_color.g = cur_fill_color.b = 0;
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cur_fill_color_id = install_fill_color(&cur_fill_color);
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cur_has_fill = true;
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cur_stroke_color.r = cur_stroke_color.g = cur_stroke_color.b = 0;
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cur_stroke_color_id = install_stroke_color(&cur_stroke_color);
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cur_has_stroke = false;
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rise_manager.reset();
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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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}
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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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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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// 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());
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if(!(new_font_info->id == cur_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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// TODO: consider the font matrix and estimate the metrics
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if(new_font_info->is_type3 || cur_font_info->is_type3)
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_DIV);
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}
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else
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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}
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cur_font_info = new_font_info;
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}
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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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// backup the current ctm for need_recheck_position
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double old_ctm[6];
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memcpy(old_ctm, cur_text_tm, sizeof(old_ctm));
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// ctm & text ctm & hori scale
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if(all_changed || ctm_changed || text_mat_changed || hori_scale_changed)
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{
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double new_text_tm[6];
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const double * m1 = state->getCTM();
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const double * m2 = state->getTextMat();
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double hori_scale = state->getHorizScaling();
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new_text_tm[0] = (m1[0] * m2[0] + m1[2] * m2[1]) * hori_scale;
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new_text_tm[1] = (m1[1] * m2[0] + m1[3] * m2[1]) * hori_scale;
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new_text_tm[2] = m1[0] * m2[2] + m1[2] * m2[3];
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new_text_tm[3] = m1[1] * m2[2] + m1[3] * m2[3];
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new_text_tm[4] = m1[0] * m2[4] + m1[2] * m2[5] + m1[4];
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new_text_tm[5] = m1[1] * m2[4] + m1[3] * m2[5] + m1[5];
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//new_text_tm[4] = new_text_tm[5] = 0;
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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
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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 natrual 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 = -new_draw_font_size;
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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(font_size_manager.install(new_draw_font_size))
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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}
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if(!(tm_equal(new_draw_text_tm, draw_text_tm, 4)))
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_DIV);
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memcpy(draw_text_tm, new_draw_text_tm, sizeof(draw_text_tm));
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cur_ttm_id = install_transform_matrix(draw_text_tm);
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}
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}
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// see if we can merge with the current line
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// depends: rise & text position & transformation
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if(need_recheck_position)
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{
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// try to transform the old origin under the new TM
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/*
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* OldTM * (draw_tx, draw_ty, 1)^T = CurTM * (draw_tx + dx, draw_ty + dy, 1)^T
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*
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* OldTM[4] = CurTM[0] * dx + CurTM[2] * dy + CurTM[4]
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* OldTM[5] = CurTM[1] * dx + CurTM[3] * dy + CurTM[5]
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*
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* We just care if we can map the origin y to the same new y
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* So just let dy = cur_y - old_y, and try to solve dx
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*
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* TODO, writing mode, set dx and solve dy
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*/
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bool merged = false;
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if(tm_equal(old_ctm, cur_text_tm, 4))
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{
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double dy = cur_ty - draw_ty;
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double tdx = old_ctm[4] - cur_text_tm[4] - cur_text_tm[2] * dy;
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double tdy = old_ctm[5] - cur_text_tm[5] - cur_text_tm[3] * dy;
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if(equal(cur_text_tm[0] * tdy, cur_text_tm[1] * tdx))
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{
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if(is_positive(cur_text_tm[0]))
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{
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draw_tx += tdx / cur_text_tm[0];
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draw_ty += dy;
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merged = true;
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}
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else if (is_positive(cur_text_tm[1]))
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{
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draw_tx += tdy / cur_text_tm[1];
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draw_ty += dy;
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merged = true;
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}
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else
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{
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if((equal(tdx,0)) && (equal(tdy,0)))
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{
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// free
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draw_tx = cur_tx;
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draw_ty += dy;
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merged = true;
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}
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// else fail
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}
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}
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//else no solution
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}
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// else force new line
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if(!merged)
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_DIV);
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}
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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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&& (letter_space_manager.install(state->getCharSpace() * draw_text_scale)))
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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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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&& (word_space_manager.install(state->getWordSpace() * draw_text_scale)))
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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}
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// color
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if(all_changed || fill_color_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 FILL[8] = { true, false, true, false, true, false, true, false };
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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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bool is_filled = FILL[idx];
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bool is_stroked = STROKE[idx];
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// fill
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if(is_filled)
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{
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GfxRGB new_color;
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state->getFillRGB(&new_color);
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if(!cur_has_fill
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|| (!GfxRGB_equal()(new_color, cur_fill_color))
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)
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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cur_fill_color = new_color;
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cur_fill_color_id = install_fill_color(&new_color);
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}
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}
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else
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{
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cur_fill_color_id = install_fill_color(nullptr);
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}
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cur_has_fill = is_filled;
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// stroke
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if(is_stroked)
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{
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GfxRGB new_color;
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state->getStrokeRGB(&new_color);
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if(!cur_has_stroke
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|| (!GfxRGB_equal()(new_color, cur_stroke_color))
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)
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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cur_stroke_color = new_color;
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cur_stroke_color_id = install_stroke_color(&new_color);
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}
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}
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else
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{
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cur_stroke_color_id = install_stroke_color(nullptr);
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}
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cur_has_stroke = is_stroked;
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}
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// rise
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// depends draw_text_scale
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if((all_changed || rise_changed || draw_text_scale_changed)
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&& (rise_manager.install(state->getRise() * draw_text_scale)))
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{
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new_line_state = max<NewLineState>(new_line_state, NLS_SPAN);
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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(!line_opened)
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{
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new_line_state = NLS_DIV;
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}
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if(new_line_state == NLS_DIV)
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{
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close_text_line();
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text_line_buf->reset(state);
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//resync position
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draw_ty = cur_ty;
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draw_tx = cur_tx;
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}
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else
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{
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// align horizontal position
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// try to merge with the last line if possible
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double target = (cur_tx - draw_tx) * draw_text_scale;
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if(abs(target) < param->h_eps)
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{
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// ignore it
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}
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else
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{
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text_line_buf->append_offset(target);
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draw_tx += target / draw_text_scale;
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}
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}
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if(new_line_state != NLS_NONE)
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{
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text_line_buf->append_state();
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}
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line_opened = true;
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}
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void HTMLRenderer::close_text_line()
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{
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if(line_opened)
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{
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line_opened = false;
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text_line_buf->flush();
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}
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}
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} //namespace pdf2htmlEX
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