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netsurf/frontends/gtk/plotters.c

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/*
* Copyright 2006 Rob Kendrick <rjek@rjek.com>
* Copyright 2005 James Bursa <bursa@users.sourceforge.net>
*
* 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
* GTK and Cairo plotter implementations.
*
* Uses Cairo drawing primitives to render browser output.
* \todo remove the use of the gdk structure for clipping
*/
#include <math.h>
#include <assert.h>
#include <gdk/gdk.h>
#include <gtk/gtk.h>
#include "utils/log.h"
#include "netsurf/plotters.h"
#include "utils/nsoption.h"
#include "gtk/layout_pango.h"
#include "gtk/plotters.h"
#include "gtk/scaffolding.h"
#include "gtk/bitmap.h"
cairo_t *current_cr;
static GdkRectangle cliprect;
/**
* Set cairo context colour to nsgtk colour.
*
* \param c the netsurf colour to set in cairo
*/
void nsgtk_set_colour(colour c)
{
cairo_set_source_rgba(current_cr,
(c & 0xff) / 255.0,
((c & 0xff00) >> 8) / 255.0,
((c & 0xff0000) >> 16) / 255.0,
1.0);
}
/**
* Set cairo context to solid plot operation.
*/
static inline void nsgtk_set_solid(void)
{
double dashes = 0;
cairo_set_dash(current_cr, &dashes, 0, 0);
}
/**
* Set cairo context to dotted plot operation.
*/
static inline void nsgtk_set_dotted(void)
{
double cdashes[] = { 1.0, 2.0 };
cairo_set_dash(current_cr, cdashes, 2, 0);
}
/**
* Set cairo context to dashed plot operation.
*/
static inline void nsgtk_set_dashed(void)
{
double cdashes[] = { 8.0, 2.0 };
cairo_set_dash(current_cr, cdashes, 2, 0);
}
/**
* Set cairo context line width.
*/
static inline void nsgtk_set_line_width(plot_style_fixed width)
{
if (width == 0) {
cairo_set_line_width(current_cr, 1);
} else {
cairo_set_line_width(current_cr,
plot_style_fixed_to_double(width));
}
}
/**
* \brief Sets a clip rectangle for subsequent plot operations.
*
* \param ctx The current redraw context.
* \param clip The rectangle to limit all subsequent plot
* operations within.
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_clip(const struct redraw_context *ctx, const struct rect *clip)
{
cairo_reset_clip(current_cr);
cairo_rectangle(current_cr, clip->x0, clip->y0,
clip->x1 - clip->x0, clip->y1 - clip->y0);
cairo_clip(current_cr);
cliprect.x = clip->x0;
cliprect.y = clip->y0;
cliprect.width = clip->x1 - clip->x0;
cliprect.height = clip->y1 - clip->y0;
return NSERROR_OK;
}
/**
* Plots an arc
*
* plot an arc segment around (x,y), anticlockwise from angle1
* to angle2. Angles are measured anticlockwise from
* horizontal, in degrees.
*
* \param ctx The current redraw context.
* \param style Style controlling the arc plot.
* \param x The x coordinate of the arc.
* \param y The y coordinate of the arc.
* \param radius The radius of the arc.
* \param angle1 The start angle of the arc.
* \param angle2 The finish angle of the arc.
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_arc(const struct redraw_context *ctx,
const plot_style_t *style,
int x, int y, int radius, int angle1, int angle2)
{
nsgtk_set_colour(style->fill_colour);
nsgtk_set_solid();
cairo_set_line_width(current_cr, 1);
cairo_arc(current_cr, x, y, radius,
(angle1 + 90) * (M_PI / 180),
(angle2 + 90) * (M_PI / 180));
cairo_stroke(current_cr);
return NSERROR_OK;
}
/**
* Plots a circle
*
* Plot a circle centered on (x,y), which is optionally filled.
*
* \param ctx The current redraw context.
* \param style Style controlling the circle plot.
* \param x x coordinate of circle centre.
* \param y y coordinate of circle centre.
* \param radius circle radius.
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_disc(const struct redraw_context *ctx,
const plot_style_t *style,
int x, int y, int radius)
{
if (style->fill_type != PLOT_OP_TYPE_NONE) {
nsgtk_set_colour(style->fill_colour);
nsgtk_set_solid();
cairo_set_line_width(current_cr, 0);
cairo_arc(current_cr, x, y, radius, 0, M_PI * 2);
cairo_fill(current_cr);
cairo_stroke(current_cr);
}
if (style->stroke_type != PLOT_OP_TYPE_NONE) {
nsgtk_set_colour(style->stroke_colour);
switch (style->stroke_type) {
case PLOT_OP_TYPE_SOLID: /* Solid colour */
default:
nsgtk_set_solid();
break;
case PLOT_OP_TYPE_DOT: /* Doted plot */
nsgtk_set_dotted();
break;
case PLOT_OP_TYPE_DASH: /* dashed plot */
nsgtk_set_dashed();
break;
}
nsgtk_set_line_width(style->stroke_width);
cairo_arc(current_cr, x, y, radius, 0, M_PI * 2);
cairo_stroke(current_cr);
}
return NSERROR_OK;
}
/**
* Plots a line
*
* plot a line from (x0,y0) to (x1,y1). Coordinates are at
* centre of line width/thickness.
*
* \param ctx The current redraw context.
* \param style Style controlling the line plot.
* \param line A rectangle defining the line to be drawn
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_line(const struct redraw_context *ctx,
const plot_style_t *style,
const struct rect *line)
{
nsgtk_set_colour(style->stroke_colour);
switch (style->stroke_type) {
case PLOT_OP_TYPE_SOLID: /* Solid colour */
default:
nsgtk_set_solid();
break;
case PLOT_OP_TYPE_DOT: /* Doted plot */
nsgtk_set_dotted();
break;
case PLOT_OP_TYPE_DASH: /* dashed plot */
nsgtk_set_dashed();
break;
}
if (style->stroke_type != PLOT_OP_TYPE_NONE) {
nsgtk_set_colour(style->stroke_colour);
}
nsgtk_set_line_width(style->stroke_width);
/* core expects horizontal and vertical lines to be on pixels, not
* between pixels
*/
cairo_move_to(current_cr,
(line->x0 == line->x1) ? line->x0 + 0.5 : line->x0,
(line->y0 == line->y1) ? line->y0 + 0.5 : line->y0);
cairo_line_to(current_cr,
(line->x0 == line->x1) ? line->x1 + 0.5 : line->x1,
(line->y0 == line->y1) ? line->y1 + 0.5 : line->y1);
cairo_stroke(current_cr);
return NSERROR_OK;
}
/**
* Plot a caret.
*
* @note It is assumed that the plotters have been set up.
*/
void nsgtk_plot_caret(int x, int y, int h)
{
nsgtk_set_solid(); /* solid line */
nsgtk_set_colour(0); /* black */
cairo_set_line_width(current_cr, 1); /* thin line */
/* core expects horizontal and vertical lines to be on pixels, not
* between pixels */
cairo_move_to(current_cr, x + 0.5, y);
cairo_line_to(current_cr, x + 0.5, y + h - 1);
cairo_stroke(current_cr);
}
/**
* Plots a rectangle.
*
* The rectangle can be filled an outline or both controlled
* by the plot style The line can be solid, dotted or
* dashed. Top left corner at (x0,y0) and rectangle has given
* width and height.
*
* \param ctx The current redraw context.
* \param style Style controlling the rectangle plot.
* \param rect A rectangle defining the line to be drawn
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_rectangle(const struct redraw_context *ctx,
const plot_style_t *style,
const struct rect *rect)
{
if (style->fill_type != PLOT_OP_TYPE_NONE) {
nsgtk_set_colour(style->fill_colour);
nsgtk_set_solid();
cairo_set_line_width(current_cr, 0);
cairo_rectangle(current_cr,
rect->x0,
rect->y0,
rect->x1 - rect->x0,
rect->y1 - rect->y0);
cairo_fill(current_cr);
cairo_stroke(current_cr);
}
if (style->stroke_type != PLOT_OP_TYPE_NONE) {
nsgtk_set_colour(style->stroke_colour);
switch (style->stroke_type) {
case PLOT_OP_TYPE_SOLID: /* Solid colour */
default:
nsgtk_set_solid();
break;
case PLOT_OP_TYPE_DOT: /* Doted plot */
nsgtk_set_dotted();
break;
case PLOT_OP_TYPE_DASH: /* dashed plot */
nsgtk_set_dashed();
break;
}
nsgtk_set_line_width(style->stroke_width);
cairo_rectangle(current_cr,
rect->x0 + 0.5,
rect->y0 + 0.5,
rect->x1 - rect->x0,
rect->y1 - rect->y0);
cairo_stroke(current_cr);
}
return NSERROR_OK;
}
/**
* Plot a polygon
*
* Plots a filled polygon with straight lines between
* points. The lines around the edge of the ploygon are not
* plotted. The polygon is filled with the non-zero winding
* rule.
*
* \param ctx The current redraw context.
* \param style Style controlling the polygon plot.
* \param p verticies of polygon
* \param n number of verticies.
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_polygon(const struct redraw_context *ctx,
const plot_style_t *style,
const int *p,
unsigned int n)
{
unsigned int i;
nsgtk_set_colour(style->fill_colour);
nsgtk_set_solid();
cairo_set_line_width(current_cr, 0);
cairo_move_to(current_cr, p[0], p[1]);
for (i = 1; i != n; i++) {
cairo_line_to(current_cr, p[i * 2], p[i * 2 + 1]);
}
cairo_fill(current_cr);
cairo_stroke(current_cr);
return NSERROR_OK;
}
/**
* Plots a path.
*
* Path plot consisting of cubic Bezier curves. Line and fill colour is
* controlled by the plot style.
*
* \param ctx The current redraw context.
* \param pstyle Style controlling the path plot.
* \param p elements of path
* \param n nunber of elements on path
* \param transform A transform to apply to the path.
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_path(const struct redraw_context *ctx,
const plot_style_t *pstyle,
const float *p,
unsigned int n,
const float transform[6])
{
unsigned int i;
cairo_matrix_t old_ctm, n_ctm;
if (n == 0)
return NSERROR_OK;
if (p[0] != PLOTTER_PATH_MOVE) {
NSLOG(netsurf, INFO, "Path does not start with move");
return NSERROR_INVALID;
}
/* Save CTM */
cairo_get_matrix(current_cr, &old_ctm);
/* Set up line style and width */
nsgtk_set_line_width(pstyle->stroke_width);
nsgtk_set_solid();
/* Load new CTM */
n_ctm.xx = transform[0];
n_ctm.yx = transform[1];
n_ctm.xy = transform[2];
n_ctm.yy = transform[3];
n_ctm.x0 = transform[4] + old_ctm.x0;
n_ctm.y0 = transform[5] + old_ctm.y0;
cairo_set_matrix(current_cr, &n_ctm);
/* Construct path */
for (i = 0; i < n; ) {
if (p[i] == PLOTTER_PATH_MOVE) {
cairo_move_to(current_cr, p[i+1], p[i+2]);
i += 3;
} else if (p[i] == PLOTTER_PATH_CLOSE) {
cairo_close_path(current_cr);
i++;
} else if (p[i] == PLOTTER_PATH_LINE) {
cairo_line_to(current_cr, p[i+1], p[i+2]);
i += 3;
} else if (p[i] == PLOTTER_PATH_BEZIER) {
cairo_curve_to(current_cr, p[i+1], p[i+2],
p[i+3], p[i+4],
p[i+5], p[i+6]);
i += 7;
} else {
NSLOG(netsurf, INFO, "bad path command %f", p[i]);
/* Reset matrix for safety */
cairo_set_matrix(current_cr, &old_ctm);
return NSERROR_INVALID;
}
}
/* Restore original CTM */
cairo_set_matrix(current_cr, &old_ctm);
/* Now draw path */
if (pstyle->fill_colour != NS_TRANSPARENT) {
nsgtk_set_colour(pstyle->fill_colour);
if (pstyle->stroke_colour != NS_TRANSPARENT) {
/* Fill & Stroke */
cairo_fill_preserve(current_cr);
nsgtk_set_colour(pstyle->stroke_colour);
cairo_stroke(current_cr);
} else {
/* Fill only */
cairo_fill(current_cr);
}
} else if (pstyle->stroke_colour != NS_TRANSPARENT) {
/* Stroke only */
nsgtk_set_colour(pstyle->stroke_colour);
cairo_stroke(current_cr);
}
return NSERROR_OK;
}
/**
* Plot a bitmap
*
* Tiled plot of a bitmap image. (x,y) gives the top left
* coordinate of an explicitly placed tile. From this tile the
* image can repeat in all four directions -- up, down, left
* and right -- to the extents given by the current clip
* rectangle.
*
* The bitmap_flags say whether to tile in the x and y
* directions. If not tiling in x or y directions, the single
* image is plotted. The width and height give the dimensions
* the image is to be scaled to.
*
* \param ctx The current redraw context.
* \param bitmap The bitmap to plot
* \param x The x coordinate to plot the bitmap
* \param y The y coordiante to plot the bitmap
* \param width The width of area to plot the bitmap into
* \param height The height of area to plot the bitmap into
* \param bg the background colour to alpha blend into
* \param flags the flags controlling the type of plot operation
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_bitmap(const struct redraw_context *ctx,
struct bitmap *bitmap,
int x, int y,
int width,
int height,
colour bg,
bitmap_flags_t flags)
{
bool repeat_x = (flags & BITMAPF_REPEAT_X);
bool repeat_y = (flags & BITMAPF_REPEAT_Y);
GdkRectangle cliprect_bitmap;
cairo_surface_t *img_surface;
int img_width, img_height;
/* Bail early if we can */
if (width <= 0 || height <= 0) {
/* Nothing to plot */
return NSERROR_OK;
}
/* Copy the clip rectangle into bitmap plot clip rectangle */
cliprect_bitmap = cliprect;
/* Constrain bitmap plot rectangle for any lack of tiling */
if (!repeat_x) {
if (cliprect_bitmap.width > width) {
cliprect_bitmap.width = width;
}
if (cliprect_bitmap.x < x) {
cliprect_bitmap.x = x;
cliprect_bitmap.width -= x - cliprect_bitmap.x;
}
}
if (!repeat_y) {
if (cliprect_bitmap.height > height) {
cliprect_bitmap.height = height;
}
if (cliprect_bitmap.y < y) {
cliprect_bitmap.y = y;
cliprect_bitmap.height -= y - cliprect_bitmap.y;
}
}
/* Bail early if we can */
if (cliprect_bitmap.width <= 0 || cliprect_bitmap.height <= 0) {
/* Nothing to plot */
return NSERROR_OK;
}
/* Get the image's surface and intrinsic dimensions */
img_surface = bitmap->surface;
img_width = cairo_image_surface_get_width(img_surface);
img_height = cairo_image_surface_get_height(img_surface);
/* Set the source surface */
if ((img_width == width) && (img_height == height)) {
/* Non-scaled rendering */
cairo_set_source_surface(current_cr, img_surface, x, y);
/* Enable tiling if we're repeating */
if (repeat_x || repeat_y) {
cairo_pattern_set_extend(
cairo_get_source(current_cr),
CAIRO_EXTEND_REPEAT);
}
/* Render the bitmap */
cairo_rectangle(current_cr,
cliprect_bitmap.x,
cliprect_bitmap.y,
cliprect_bitmap.width,
cliprect_bitmap.height);
cairo_fill(current_cr);
} else {
/* Scaled rendering */
double scale_x = (double)width / img_width;
double scale_y = (double)height / img_height;
/* Save cairo rendering context state before scaling */
cairo_save(current_cr);
cairo_scale(current_cr, scale_x, scale_y);
cairo_set_source_surface(current_cr, img_surface,
x / scale_x, y / scale_y);
/* Enable tiling if we're repeating */
if (repeat_x || repeat_y) {
cairo_pattern_set_extend(
cairo_get_source(current_cr),
CAIRO_EXTEND_REPEAT);
}
/* Render the bitmap */
cairo_rectangle(current_cr,
cliprect_bitmap.x / scale_x,
cliprect_bitmap.y / scale_y,
cliprect_bitmap.width / scale_x,
cliprect_bitmap.height / scale_y);
cairo_fill(current_cr);
/* Restore pre-scaling cairo rendering state */
cairo_restore(current_cr);
}
return NSERROR_OK;
}
/**
* Text plotting.
*
* \param ctx The current redraw context.
* \param fstyle plot style for this text
* \param x x coordinate
* \param y y coordinate
* \param text UTF-8 string to plot
* \param length length of string, in bytes
* \return NSERROR_OK on success else error code.
*/
static nserror
nsgtk_plot_text(const struct redraw_context *ctx,
const struct plot_font_style *fstyle,
int x,
int y,
const char *text,
size_t length)
{
return nsfont_paint(x, y, text, length, fstyle);
}
/** GTK plotter table */
const struct plotter_table nsgtk_plotters = {
.clip = nsgtk_plot_clip,
.arc = nsgtk_plot_arc,
.disc = nsgtk_plot_disc,
.line = nsgtk_plot_line,
.rectangle = nsgtk_plot_rectangle,
.polygon = nsgtk_plot_polygon,
.path = nsgtk_plot_path,
.bitmap = nsgtk_plot_bitmap,
.text = nsgtk_plot_text,
.option_knockout = true
};