netsurf/pdf/pdf_plotters.c

/*
 * Copyright 2008 Adam Blokus <adamblokus@gmail.com>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 /** \file
 * Target independent PDF plotting using Haru Free PDF Library.
 * Contains also the current solution for some text being cropped over page
 * boundaries a 'fuzzy' bottom margin.
  */

#include "utils/config.h"
#ifdef WITH_PDF_EXPORT

#include <stdlib.h>
#include <string.h>
#include "hpdf.h"

#include "desktop/plotters.h"
#include "desktop/print.h"
#include "desktop/printer.h"
#include "pdf/pdf_plotters.h"
#include "utils/log.h"
#include "utils/utils.h"
#include "image/bitmap.h"

#include "font_haru.h"

#define R(x) ((  (x) & 0x0000ff     )/256.0)
#define G(x) ((( (x) & 0x00ff00)>>8 )/256.0)
#define B(x) ((( (x) & 0xff0000)>>16)/256.0)
 
/*#define PDF_DEBUG*/

static bool pdf_plot_clg(colour c);
static bool pdf_plot_rectangle(int x0, int y0, int width, int height,
		int line_width, colour c, bool dotted, bool dashed);
static bool pdf_plot_line(int x0, int y0, int x1, int y1, int width,
		colour c, bool dotted, bool dashed);
static bool pdf_plot_polygon(int *p, unsigned int n, colour fill);
static bool pdf_plot_fill(int x0, int y0, int x1, int y1, colour c);
static bool pdf_plot_clip(int clip_x0, int clip_y0,
		int clip_x1, int clip_y1);
static bool pdf_plot_text(int x, int y, const struct css_style *style,
		const char *text, size_t length, colour bg, colour c);
static bool pdf_plot_disc(int x, int y, int radius, colour c, bool filled);
static bool pdf_plot_arc(int x, int y, int radius, int angle1, int angle2,
    		colour c);
static bool pdf_plot_bitmap(int x, int y, int width, int height,
		struct bitmap *bitmap, colour bg, struct content *content);
static bool pdf_plot_bitmap_tile(int x, int y, int width, int height,
		struct bitmap *bitmap, colour bg,
		bool repeat_x, bool repeat_y, struct content *content);
static bool pdf_plot_path(float *p, unsigned int n, colour fill, float width,
		colour c, float *transform);

static void pdf_set_solid(void);
static void pdf_set_dashed(void);
static void pdf_set_dotted(void);

static void pdf_page_apply_notext_clip(void);

static HPDF_Image pdf_extract_image(struct bitmap *bitmap, struct content *content);

static void error_handler(HPDF_STATUS error_no, HPDF_STATUS detail_no,
		void *user_data);

#ifdef PDF_DEBUG
static void pdf_plot_grid(int x_dist,int y_dist,unsigned int colour);
#endif

/*PDF Plotter - current doc,page and font*/
static HPDF_Doc pdf_doc;
static HPDF_Page pdf_page;
static HPDF_Font pdf_font;

/*PDF Page size*/
static HPDF_REAL page_height, page_width;

/*Remeber if pdf_plot_clip was invoked for current page*/
static bool page_clipped;

static struct print_settings* settings;
/*this is added to the bottom margin as a place where text can be plotted
 when it overflows just a little bit*/
static float text_margin;

static const struct plotter_table pdf_plotters = {
	pdf_plot_clg,
	pdf_plot_rectangle,
	pdf_plot_line,
	pdf_plot_polygon,
	pdf_plot_fill,
	pdf_plot_clip,
	pdf_plot_text,
	pdf_plot_disc,
	pdf_plot_arc,
	pdf_plot_bitmap,
	pdf_plot_bitmap_tile,
	NULL,
	NULL,
	NULL,
	pdf_plot_path,
	false
};

struct printer pdf_printer= {
	&pdf_plotters,
	pdf_begin,
	pdf_next_page,
	pdf_end
};

bool pdf_plot_clg(colour c)
{
	return true;
}

bool pdf_plot_rectangle(int x0, int y0, int width, int height,
		int line_width, colour c, bool dotted, bool dashed)
{
#ifdef PDF_DEBUG
	LOG(("."));
#endif		
	HPDF_Page_SetLineWidth(pdf_page, line_width);		
	
	if (dotted)
		pdf_set_dotted();
	else if (dashed)
		pdf_set_dashed();
	
	HPDF_Page_SetRGBStroke(pdf_page, R(c), G(c), B(c));
	HPDF_Page_Rectangle(pdf_page, x0, page_height - y0 + height, width, height);
	HPDF_Page_Stroke(pdf_page);
	
	if (dotted||dashed)
		pdf_set_solid();

	return true;
}

bool pdf_plot_line(int x0, int y0, int x1, int y1, int width, 
		colour c, bool dotted, bool dashed)
{
#ifdef PDF_DEBUG
	LOG(("."));
#endif				
	HPDF_Page_SetLineWidth(pdf_page, width);
			
	if (dotted)
		pdf_set_dotted();
	else if (dashed)
		pdf_set_dashed();
	
	HPDF_Page_SetRGBStroke(pdf_page, R(c), G(c), B(c));
	HPDF_Page_SetLineWidth(pdf_page, width);
	HPDF_Page_MoveTo(pdf_page, x0, page_height - y0);
	HPDF_Page_LineTo(pdf_page, x1, page_height - y1);
	HPDF_Page_Stroke(pdf_page);
	
	if (dotted||dashed)
		pdf_set_solid();

	return true;
}

bool pdf_plot_polygon(int *p, unsigned int n, colour fill)
{
	int i;
#ifdef PDF_DEBUG
	int pmaxx = p[0], pmaxy = p[1];
	int pminx = p[0], pminy = p[1];
	LOG(("."));
#endif		
	if (n == 0)
		return true;
	
	HPDF_Page_SetRGBFill(pdf_page, R(fill), G(fill), B(fill));	
	HPDF_Page_MoveTo(pdf_page, p[0], page_height - p[1]);
	
	for (i = 1 ; i<n ; i++) {
		HPDF_Page_LineTo(pdf_page, p[i*2], page_height - p[i*2+1]);	
#ifdef PDF_DEBUG
		pmaxx = max(pmaxx, p[i*2]);
		pmaxy = max(pmaxy, p[i*2+1]);
		pminx = min(pminx, p[i*2]);
		pminy = min(pminy, p[i*2+1]);
#endif
	}
	
#ifdef PDF_DEBUG
	LOG(("%d %d %d %d %f", pminx, pminy, pmaxx, pmaxy, page_height-pminy));
#endif
		
	HPDF_Page_LineTo(pdf_page, p[0], page_height - p[1]);	
	HPDF_Page_Fill(pdf_page);

	return true;
}

bool pdf_plot_fill(int x0, int y0, int x1, int y1, colour c)
{	
#ifdef PDF_DEBUG
	LOG(("%d %d %d %d %f %X", x0, y0, x1, y1, page_height-y0, c));
#endif
	
	/*Normalize boundaries of the area - to prevent overflows.
	  It is needed only in a few functions, where integers are subtracted.
	  When the whole browser window is meant min and max int values are used
	  what must be handled in paged output.
	*/
	x0 = min(max(x0, 0), page_width);
	y0 = min(max(y0, 0), page_height);
	x1 = min(max(x1, 0), page_width);
	y1 = min(max(y1, 0), page_height);
	
	HPDF_Page_SetRGBFill(pdf_page, R(c), G(c), B(c));
	HPDF_Page_Rectangle(pdf_page, x0, page_height - y1, x1-x0, y1-y0);
	HPDF_Page_Fill(pdf_page);
	
	return true;
}

bool pdf_plot_clip(int clip_x0, int clip_y0, int clip_x1, int clip_y1)
{
#ifdef PDF_DEBUG
	LOG(("%d %d %d %d", clip_x0, clip_y0, clip_x1, clip_y1));
#endif
	
	HPDF_Page_GRestore(pdf_page);
	if (page_clipped)
		HPDF_Page_GRestore(pdf_page);

	/*Normalize cllipping area - to prevent overflows.
	  See comment in pdf_plot_fill.
	*/
	clip_x0 = min(max(clip_x0, 0), page_width);
	clip_y0 = min(max(clip_y0, 0), page_height);
	clip_x1 = min(max(clip_x1, 0), page_width);
	clip_y1 = min(max(clip_y1, 0), page_height);
	
	
	HPDF_Page_GSave(pdf_page);
	HPDF_Page_Rectangle(pdf_page, clip_x0, page_height-clip_y1, 
			     clip_x1-clip_x0, clip_y1-clip_y0);
	HPDF_Page_Clip(pdf_page);
	HPDF_Page_EndPath(pdf_page);
	
	pdf_page_apply_notext_clip();
	
	page_clipped = true;
	
	return true;
}

bool pdf_plot_text(int x, int y, const struct css_style *style, 
		const char *text, size_t length, colour bg, colour c)
{
#ifdef PDF_DEBUG
	LOG((". %d %d %s", x, y, text));
#endif
	char *word;
	HPDF_REAL size;
	bool fuzzy=false;
	float text_bottom_position, descent;
	
	if (length == 0)
		return true;

	if (style->font_size.value.length.unit  == CSS_UNIT_PX)
		size = style->font_size.value.length.value;
	else
		size = css_len2pt(&style->font_size.value.length, style);
	
	haru_nsfont_apply_style(style, pdf_doc, pdf_page, &pdf_font);
	
	descent = size * (HPDF_Font_GetDescent(pdf_font) / 1000.0);
	text_bottom_position = page_height - y + descent;
	
  	if ( (size > y) && (y - descent <= text_margin) )
  		return true;
 	
	if (text_bottom_position < settings->margins[MARGINBOTTOM] + text_margin ) {
		if ((text_bottom_position >= settings->margins[MARGINBOTTOM]) &&
				(page_height - (y - size) >
				settings->margins[MARGINBOTTOM] + text_margin)) {
			fuzzy = true;
			HPDF_Page_GRestore(pdf_page);
		}
	}
	
	word = (char*) malloc( sizeof(char) * (length+1) );
	if (word == NULL)
		return false;
	
	memcpy(word, text, length);
	word[length] = '\0';
	
	HPDF_Page_SetRGBFill(pdf_page, R(c), G(c), B(c));
	
	HPDF_Page_BeginText(pdf_page);
	HPDF_Page_SetFontAndSize (pdf_page, pdf_font, size);
	HPDF_Page_TextOut (pdf_page, x, page_height - y, word);
	HPDF_Page_EndText(pdf_page);
	
	if (fuzzy)
		pdf_page_apply_notext_clip();
	
	free(word);
	
	return true;
}

bool pdf_plot_disc(int x, int y, int radius, colour c, bool filled)
{
#ifdef PDF_DEBUG
	LOG(("."));
#endif		
	if (filled)
		HPDF_Page_SetRGBFill(pdf_page, R(c), G(c), B(c));
	else
		HPDF_Page_SetRGBStroke(pdf_page, R(c), G(c), B(c));
	
	HPDF_Page_Circle(pdf_page, x, page_height-y, radius);
	
	if (filled)
		HPDF_Page_Fill(pdf_page);
	else
		HPDF_Page_Stroke(pdf_page);
	
	return true;
}

bool pdf_plot_arc(int x, int y, int radius, int angle1, int angle2, colour c)
{
#ifdef PDF_DEBUG
	LOG(("%d %d %d %d %d %X", x, y, radius, angle1, angle2, c));
#endif		
	
	/*Normalize angles*/
	angle1 %= 360;
	angle2 %= 360;
	if (angle1 > angle2)
		angle1 -= 360;
	
	HPDF_Page_SetRGBStroke(pdf_page, R(c), G(c), B(c));
	
	HPDF_Page_Arc(pdf_page, x, page_height-y, radius, angle1, angle2);
	
	HPDF_Page_Stroke(pdf_page);
	return true;
}

bool pdf_plot_bitmap(int x, int y, int width, int height,
		struct bitmap *bitmap, colour bg, struct content *content)
{
	HPDF_Image image;

#ifdef PDF_DEBUG
	LOG(("%d %d %d %d %X %X %X", x, y, width, height,
	     bitmap, bg, content));
#endif
 	if (width == 0 || height == 0)
 		return true;
	
	image = pdf_extract_image(bitmap, content);	
	
	if (!image)
		return false;
	
	HPDF_Page_DrawImage(pdf_page, image,
			x, page_height-y-height,
			width, height);	
	return true;
	

}

bool pdf_plot_bitmap_tile(int x, int y, int width, int height,
		struct bitmap *bitmap, colour bg,
  		bool repeat_x, bool repeat_y, struct content *content)
{
	HPDF_Image image;
	
#ifdef PDF_DEBUG
	LOG(("%d %d %d %d %X %X %X", x, y, width, height,
	     bitmap, bg, content));
#endif
 	if (width == 0 || height == 0)
 		return true;	
	
	image = pdf_extract_image(bitmap, content);	
	
	if (image) {
		/*The position of the next tile*/
		HPDF_REAL current_x, current_y ;	
		HPDF_REAL max_width, max_height;
		
		max_width =  (repeat_x ? page_width : width);
		max_height = (repeat_y ? page_height: height);
		
		
		for (current_y=0; current_y < max_height; current_y += height)
			for (current_x=0; current_x < max_width; current_x += width)
				HPDF_Page_DrawImage(pdf_page, image,
						current_x,
      						page_height-current_y-height,
      						width, height);
		
		return true;
	}
	else
		return false;
	
	return true;
}

HPDF_Image pdf_extract_image(struct bitmap *bitmap, struct content *content)
{
	HPDF_Image image = NULL,smask;
	char *img_buffer, *rgb_buffer, *alpha_buffer;
	int img_width, img_height, img_rowstride;
	int i, j;
	
	if (content) {
		/*Not sure if I don't have to check if downloading has been
		finished.
		Other way - lock pdf plotting while fetching a website
		*/
		switch(content->type){
			/*Handle "embeddable" types of images*/
			/*TODO:something seems to be wrong with HPDF_LoadJpegImageFromMem
			  no embedding at all till I'll figure it out
			*/			
// 			case CONTENT_JPEG:
// 				image = HPDF_LoadJpegImageFromMem(pdf_doc,
// 						content->source_data,
// 						content->total_size);
// 				break;
				
			/*Disabled until HARU PNG support will be more stable.
			
			case CONTENT_PNG:
				image = HPDF_LoadPngImageFromMem(pdf_doc,
						content->source_data,
						content->total_size);
				break;*/	
		}	
	}
	
	if (!image) {
		/*Handle pixmaps*/
		img_buffer = bitmap_get_buffer(bitmap);
		img_width = bitmap_get_width(bitmap);
		img_height = bitmap_get_height(bitmap);
		img_rowstride = bitmap_get_rowstride(bitmap);
		
		rgb_buffer = (char*)malloc(3 * img_width * img_height);
		if (rgb_buffer == NULL) {
			LOG(("Not enough memory to create RGB buffer"));
			return NULL;
		}
		
		alpha_buffer = (char*)malloc(img_width * img_height);
		if (alpha_buffer == NULL) {
			LOG(("Not enough memory to create alpha buffer"));
			free(rgb_buffer);
			return NULL;
		}
		
			
		for (i = 0; i<img_height; i++)
			for (j = 0 ; j<img_width ; j++) {
				rgb_buffer[((i * img_width) + j) * 3] =
				  img_buffer[(i * img_rowstride) + (j * 4)];
				
				rgb_buffer[(((i * img_width) + j) * 3) + 1] =
				  img_buffer[(i * img_rowstride) + (j * 4) + 1];
				
				rgb_buffer[(((i * img_width) + j) * 3) + 2] =
				  img_buffer[(i * img_rowstride) + (j * 4) + 2];
				
				alpha_buffer[(i * img_width)+j] =
				  img_buffer[(i * img_rowstride) + (j * 4) + 3];
			}
			
			smask = HPDF_LoadRawImageFromMem(pdf_doc, alpha_buffer,
							img_width, img_height,
     							HPDF_CS_DEVICE_GRAY, 8);
		
			image = HPDF_LoadRawImageFromMem(pdf_doc, rgb_buffer,
							img_width, img_height,
     							HPDF_CS_DEVICE_RGB, 8);
		
			if (HPDF_Image_AddSMask(pdf_doc, image,smask) != HPDF_OK)
				image = NULL;
		
			free(rgb_buffer);
			free(alpha_buffer);
	}
	
	return image;
}

static inline float transform_x(float *transform, float x, float y)
{
	return ((transform[0] * x) + (transform[2] * (-y) ) + transform[4]) * 2;
}

static inline float transform_y(float *transform, float x, float y)
{
	return page_height - (((transform[1] * x) +
			(transform[3] * (-y)) - transform[5]) * 2);
}

bool pdf_plot_path(float *p, unsigned int n, colour fill, float width,
		colour c, float *transform)
{
#ifdef PDF_DEBUG
	LOG(("."));
#endif		    
	unsigned int i;
	bool empty_path = true;

	if (n == 0)
		return true;
	
	if ((c == TRANSPARENT) && (fill == TRANSPARENT))
		return true;
	
	if (p[0] != PLOTTER_PATH_MOVE) {
		return false;
	}
	
	HPDF_Page_SetRGBFill(pdf_page, R(fill), G(fill), B(fill));
	HPDF_Page_SetRGBStroke(pdf_page, R(c), G(c), B(c));
	
	transform[0] = 0.1;
	transform[1] = 0;
	transform[2] = 0;
	transform[3] = -0.1;	
	transform[4] = 0;
	transform[5] = 0;	
	
	for (i = 0 ; i<n ; ) {
		if (p[i] == PLOTTER_PATH_MOVE) {
			HPDF_Page_MoveTo(pdf_page, 
					transform_x(transform, p[i+1], p[i+2]), 
					transform_y(transform, p[i+1], p[i+2]));
			i+= 3;
		} else if (p[i] == PLOTTER_PATH_CLOSE) {
			if (!empty_path)
				HPDF_Page_ClosePath(pdf_page);
			i++;
		} else if (p[i] == PLOTTER_PATH_LINE) {
			HPDF_Page_LineTo(pdf_page, 
					transform_x(transform, p[i+1], p[i+2]), 
					transform_y(transform, p[i+1], p[i+2]));
			i+=3;
			empty_path = false;
		} else if (p[i] == PLOTTER_PATH_BEZIER) {
			HPDF_Page_CurveTo(pdf_page, 
					transform_x(transform, p[i+1], p[i+2]),
					transform_y(transform, p[i+1], p[i+2]),
					transform_x(transform, p[i+3], p[i+4]),
					transform_y(transform, p[i+3], p[i+4]),
					transform_x(transform, p[i+5], p[i+6]),
					transform_y(transform, p[i+5], p[i+6]));
			i += 7;
			empty_path = false;
		} else {
			LOG(("bad path command %f", p[i]));
			return false;
		}
	}

	if (empty_path) {
		HPDF_Page_EndPath(pdf_page);
		return true;
	}
	
	if (fill!=TRANSPARENT) {
		if (c != TRANSPARENT)
			HPDF_Page_FillStroke(pdf_page);
		else
			HPDF_Page_Fill(pdf_page);
	}
	else
		HPDF_Page_Stroke(pdf_page);
	
	return true;
}

void pdf_set_solid()
{
	HPDF_Page_SetDash(pdf_page, NULL, 0, 0);
}

void pdf_set_dashed()
{
	HPDF_UINT16 dash_ptn[] = {3};	
	HPDF_Page_SetDash(pdf_page, dash_ptn, 1, 1);
}

void pdf_set_dotted()
{
	HPDF_UINT16 dash_ptn[] = {1};	
	HPDF_Page_SetDash(pdf_page, dash_ptn, 1, 1);
}

/** 
 * Begin pdf plotting - initialize a new document
 * \param path Output file path
 * \param pg_width page width
 * \param pg_height page height	
 */
bool pdf_begin(struct print_settings *print_settings)
{
	pdf_doc = NULL;
	
	pdf_doc = HPDF_New(error_handler, NULL);
	if (!pdf_doc) {
		LOG(("Error creating pdf_doc"));
		return false;
	}
	
	settings = print_settings;
	
	page_width = settings->page_width - settings->margins[MARGINLEFT] - 
			settings->margins[MARGINRIGHT];
	
	page_height = settings->page_height - settings->margins[MARGINTOP];
	
	text_margin = settings->margins[MARGINTEXT];

//	HPDF_SetCompressionMode(pdf_doc, HPDF_COMP_ALL); /*Compression on*/
	pdf_font = HPDF_GetFont (pdf_doc, "Times-Roman", "StandardEncoding");
	
	pdf_page = NULL;
	
#ifdef PDF_DEBUG
	LOG(("pdf_begin finishes"));
#endif	
	return true;
}


bool pdf_next_page(void)
{
#ifdef PDF_DEBUG
	if (pdf_page != NULL) {
		HPDF_Page_GRestore(pdf_page);
		if (page_clipped)
			HPDF_Page_GRestore(pdf_page);
		pdf_plot_grid(10, 10, 0xCCCCCC);
		pdf_plot_grid(100, 100, 0xCCCCFF);
	}
#endif
	pdf_page = HPDF_AddPage(pdf_doc);
	if (pdf_page == NULL)
		return false;
	
	HPDF_Page_SetWidth (pdf_page, settings->page_width);
	HPDF_Page_SetHeight(pdf_page, settings->page_height);
	
	HPDF_Page_Concat(pdf_page,1,0,0,1,settings->margins[MARGINLEFT],0);
	
	pdf_page_apply_notext_clip();
	
	page_clipped = false;
	
#ifdef PDF_DEBUG
	LOG(("%f %f", page_width, page_height));
#endif
	
	return true;
}


void pdf_end(void)
{
#ifdef PDF_DEBUG
	LOG(("pdf_end begins"));
	if (pdf_page != NULL) {
		HPDF_Page_GRestore(pdf_page);
		if (page_clipped)
			HPDF_Page_GRestore(pdf_page);
		pdf_plot_grid(10, 10, 0xCCCCCC);
		pdf_plot_grid(100, 100, 0xCCCCFF);
	}
#endif

	/*TODO: if false notify user*/
	if (settings->output)
		HPDF_SaveToFile(pdf_doc, settings->output);

	HPDF_Free(pdf_doc);

#ifdef PDF_DEBUG
	LOG(("pdf_end finishes"));
#endif
}


/**
 * Haru error handler
 * for debugging purposes - it immediately exits the program on the first error,
 * as it would otherwise flood the user with all resulting complications,
 * covering the most important error source.
*/
static void error_handler(HPDF_STATUS error_no, HPDF_STATUS detail_no,
		void *user_data)
{
	LOG(("ERROR:\n\terror_no=%x\n\tdetail_no=%d\n",	(HPDF_UINT)error_no,
			(HPDF_UINT)detail_no));
#ifdef PDF_DEBUG	
	exit(1);
#endif	
}

/**
 * This function plots a grid - used for debug purposes to check if all
 * elements' final coordinates are correct.
*/
#ifdef PDF_DEBUG
void pdf_plot_grid(int x_dist, int y_dist, unsigned int colour)
{
	int i;
	
	for (int i = x_dist ; i < page_width ; i += x_dist)
		pdf_plot_line(i, 0, i, page_height, 1, colour, false, false);
	
	for (int i = y_dist ; i < page_height ; i += x_dist)
		pdf_plot_line(0, i, page_width, i, 1, colour, false, false);
	
}
#endif

/**
 * A solution for fuzzy margins - saves the current clipping and puts the main
 * clip frame (page without margins) over it.
*/
void pdf_page_apply_notext_clip(void)
{
	/*Save state underneath*/
	HPDF_Page_GSave(pdf_page);
	
	/*Apply no-text clipping (stadard page)*/
	HPDF_Page_Rectangle(pdf_page,
			0,
       			text_margin + settings->margins[MARGINBOTTOM],
			page_width,
       			page_height - settings->margins[MARGINTOP] - text_margin);

	HPDF_Page_Clip(pdf_page);

#ifdef PDF_DEBUG
	HPDF_Page_Stroke(pdf_page);
#else
	HPDF_Page_EndPath(pdf_page);
#endif
}

#endif /* WITH_PDF_EXPORT */