Add checks for Cairo

Sat Jan  8 16:46:37 2005  Owen Taylor  <otaylor@redhat.com>

        * configure.in: Add checks for Cairo

        * pango/Makefile.am: Add libpangocairo.

        * pango/pangocairo-font.c pango/pangocairo-fontmap.c
        pango/pangocairo.h pango/pangocairo-private.h
        pango/pangocairo-fcfont.c pango/pangocairo-fcfontmap.c
        pango/pangocairo-fc.h: Start of a Cairo/FreeType backend.

        * pango/pangofc-fontmap.[ch]: Add a "get_render_key"
        virtual function to allow subclasses to specialize the
        details of how caching works. Add a default implementation
        that's a little more sophisticated than what was there
        before.

        * pango/pangoft2-private.h pangofc-font.c pangoft2.c:
        Move default implementations of has_char(), get_glyph()
        to the base class.

        * pango/pangofc-private.h pango/pangoft2-private.h:
        Move PANGO_UNITS_26_6 and friends to pango/pangofc-private.h.

        * examples/renderdemo.[ch] examples/pangoft2topgm.c
        examples/xftview.c: Allow passing in a custom function
        to transform drawing.

        * examples/Makefile.am examples/cairoview.c: Add a
        Cairo/Xlib example program.

        * examples/cairosimple.c: Simple Cairo example with
        output to a PNG.

        * pango/pango-layout.c (pango_layout_line_get_extents): Fix
        bug where line ink rect was always including 0, 0.

1 files changed, 354 insertions, 0 deletions

diff --git a/pango/pangocairo-render.c b/pango/pangocairo-render.c
new file mode 100644
index 00000000..305a5e08
--- /dev/null
+++ b/pango/pangocairo-render.c
@@ -0,0 +1,354 @@
+/* Pango
+ * pangocairo-render.c: Rendering routines to Cairo surfaces
+ *
+ * Copyright (C) 2004 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "pangocairo-private.h"
+
+typedef struct _PangoCairoRendererClass PangoCairoRendererClass;
+
+#define PANGO_CAIRO_RENDERER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_CAIRO_RENDERER, PangoCairoRendererClass))
+#define PANGO_IS_CAIRO_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_CAIRO_RENDERER))
+#define PANGO_CAIRO_RENDERER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_CAIRO_RENDERER, PangoCairoRendererClass))
+
+struct _PangoCairoRenderer
+{
+  PangoRenderer parent_instance;
+
+  cairo_t *cr;
+};
+
+struct _PangoCairoRendererClass
+{
+  PangoRendererClass parent_class;
+};
+
+G_DEFINE_TYPE (PangoCairoRenderer, pango_cairo_renderer, PANGO_TYPE_RENDERER)
+
+static void
+set_color (PangoCairoRenderer *crenderer,
+	   PangoRenderPart     part)
+{
+  PangoColor *color = pango_renderer_get_color (PANGO_RENDERER (crenderer), part);
+
+  if (color)
+    cairo_set_rgb_color (crenderer->cr,
+			 color->red / 65535.,
+			 color->green / 65535.,
+			 color->blue / 65535.);
+}
+     
+static void
+pango_cairo_renderer_draw_glyphs (PangoRenderer     *renderer,
+				  PangoFont         *font,
+				  PangoGlyphString  *glyphs,
+				  int                x,
+				  int                y)
+{
+  PangoCairoRenderer *crenderer = PANGO_CAIRO_RENDERER (renderer);
+
+  /* cairo_glyph_t is 24 bytes */
+#define MAX_STACK 40
+  
+  int i;
+  int x_position = 0;
+  cairo_glyph_t *cairo_glyphs;
+  cairo_glyph_t stack_glyphs[MAX_STACK];
+
+  cairo_save (crenderer->cr);
+
+  set_color (crenderer, PANGO_RENDER_PART_FOREGROUND);
+
+  if (glyphs->num_glyphs > MAX_STACK)
+    cairo_glyphs = g_new (cairo_glyph_t, glyphs->num_glyphs);
+  else
+    cairo_glyphs = stack_glyphs;
+
+  for (i = 0; i < glyphs->num_glyphs; i++)
+    {
+      PangoGlyphInfo *gi = &glyphs->glyphs[i];
+
+      cairo_glyphs[i].index = gi->glyph;
+      cairo_glyphs[i].x = (double)(x + x_position + gi->geometry.x_offset) / PANGO_SCALE;
+      cairo_glyphs[i].y = (double)(y + gi->geometry.y_offset) / PANGO_SCALE;
+
+      x_position += gi->geometry.width;
+    }
+
+  _pango_cairo_font_make_current (PANGO_CAIRO_FONT (font), crenderer->cr);
+  cairo_show_glyphs (crenderer->cr, cairo_glyphs, glyphs->num_glyphs);
+  
+  if (glyphs->num_glyphs > MAX_STACK)
+    g_free (cairo_glyphs);
+
+  cairo_restore (crenderer->cr);
+  
+#undef MAX_STACK
+}
+
+static void
+pango_cairo_renderer_draw_rectangle (PangoRenderer     *renderer,
+				     PangoRenderPart    part,
+				     int                x,
+				     int                y,
+				     int                width,
+				     int                height)
+{
+  PangoCairoRenderer *crenderer = PANGO_CAIRO_RENDERER (renderer);
+
+  cairo_save (crenderer->cr);
+
+  set_color (crenderer, part);
+
+  cairo_rectangle (crenderer->cr,
+		   (double)x / PANGO_SCALE, (double)y / PANGO_SCALE, 
+		   (double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
+  cairo_fill (crenderer->cr);
+  
+  cairo_restore (crenderer->cr);
+}
+
+/* Draws an error underline that looks like one of:
+ *              H       E                H
+ *     /\      /\      /\        /\      /\               -
+ *   A/  \    /  \    /  \     A/  \    /  \              |
+ *    \   \  /    \  /   /D     \   \  /    \             |
+ *     \   \/  C   \/   /        \   \/   C  \            | height = HEIGHT_SQUARES * square
+ *      \      /\  F   /          \  F   /\   \           | 
+ *       \    /  \    /            \    /  \   \G         |
+ *        \  /    \  /              \  /    \  /          |
+ *         \/      \/                \/      \/           -
+ *         B                         B       
+ * |----|
+ *   unit_width = (HEIGHT_SQUARES - 1) * square
+ *
+ * The x, y, width, height passed in give the desired bounding box;
+ * x/width are adjusted to make the underline a integer number of units
+ * wide.
+ */
+#define HEIGHT_SQUARES 2.5
+
+static void
+pango_cairo_renderer_draw_error_underline (PangoRenderer *renderer,
+					   int            x,
+					   int            y,
+					   int            width,
+					   int            height)
+{
+  PangoCairoRenderer *crenderer = PANGO_CAIRO_RENDERER (renderer);
+  cairo_t *cr = crenderer->cr;
+
+  double square = height / HEIGHT_SQUARES;
+  double unit_width = (HEIGHT_SQUARES - 1) * square;
+  int width_units = (width + unit_width / 2) / unit_width;
+  double y_top, y_bottom;
+  int i;
+  
+  cairo_save (cr);
+
+  set_color (crenderer, PANGO_RENDER_PART_UNDERLINE);
+
+  x += (width - width_units * unit_width);
+  width = width_units * unit_width;
+  
+  cairo_new_path (cr);
+  
+  y_top = y + height;
+  y_bottom = y;
+  
+  /* Bottom of squiggle */
+  cairo_move_to (cr, x - square / 2, y_top - square / 2); /* A */
+  for (i = 0; i < width_units; i += 2)
+    {
+      double x_middle = x + (i + 1) * unit_width;
+      double x_right = x + (i + 2) * unit_width;
+      
+      cairo_line_to (cr, x_middle, y_bottom); /* B */
+      
+      if (i + 1 == width_units)
+	/* Nothing */;
+      else if (i + 2 == width_units)
+	cairo_line_to (cr, x_right + square / 2, y_top - square / 2); /* D */
+      else
+	cairo_line_to (cr, x_right, y_top - square); /* C */
+    }
+  
+  /* Top of squiggle */
+  for (i -= 2; i >= 0; i -= 2)
+    {
+      double x_left = x + i * unit_width;
+      double x_middle = x + (i + 1) * unit_width;
+      double x_right = x + (i + 2) * unit_width;
+      
+      if (i + 1 == width_units)
+	cairo_line_to (cr, x_middle + square / 2, y_bottom + square / 2); /* G */
+      else
+	{
+	  if (i + 2 == width_units)
+	    cairo_line_to (cr, x_right, y_top); /* E */
+	  cairo_line_to (cr, x_middle, y_bottom + square); /* F */
+	}
+    
+      cairo_line_to (cr, x_left, y_top);   /* H */
+    }
+  
+  cairo_close_path (cr);
+  cairo_fill (cr);
+
+  cairo_restore (cr);
+}
+
+static void
+pango_cairo_renderer_init (PangoCairoRenderer *renderer)
+{
+}
+
+static void
+pango_cairo_renderer_class_init (PangoCairoRendererClass *klass)
+{
+  PangoRendererClass *renderer_class = PANGO_RENDERER_CLASS (klass);
+
+  renderer_class->draw_glyphs = pango_cairo_renderer_draw_glyphs;
+  renderer_class->draw_rectangle = pango_cairo_renderer_draw_rectangle;
+  renderer_class->draw_error_underline = pango_cairo_renderer_draw_error_underline;
+}
+
+static void
+current_point_to_origin (cairo_t *cr)
+{
+  double x, y;
+
+  cairo_current_point (cr, &x, &y);
+  cairo_translate (cr, x, y);
+}
+
+/**
+ * pango_cairo_show_glyphs:
+ * @cr: a Cairo context
+ * @font: a #PangoFont
+ * @glyphs: a #PangoGlyphString
+ * 
+ * Draws the glyphs in @glyphs in the specified cairo context.
+ * The origin of the glyphs (the left edge of the baseline) will
+ * be drawn at the current point of the cairo context.
+ *
+ * Since: 1.10
+ **/
+void
+pango_cairo_show_glyphs (cairo_t          *cr,
+			 PangoFont        *font,
+			 PangoGlyphString *glyphs)
+{
+  PangoFontMap *fontmap;
+  PangoCairoRenderer *crenderer;
+  PangoRenderer *renderer;
+
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (PANGO_IS_CAIRO_FONT (font));
+  g_return_if_fail (glyphs != NULL);
+
+  fontmap = PANGO_FC_FONT (font)->fontmap;
+  renderer = _pango_cairo_font_map_get_renderer (PANGO_CAIRO_FONT_MAP (fontmap));
+  crenderer = PANGO_CAIRO_RENDERER (renderer);
+
+  cairo_save (cr);
+  current_point_to_origin (cr);
+
+  crenderer->cr = cr;
+  pango_renderer_draw_glyphs (renderer, font, glyphs, 0, 0);
+  crenderer->cr = NULL;
+  
+  cairo_restore (cr);
+}
+
+/**
+ * pango_cairo_show_layout_line:
+ * @cr: a Cairo context
+ * @line: a #PangoLayoutLine
+ * 
+ * Draws a #PangoLayoutLine in the specified cairo context.
+ * The origin of the glyphs (the left edge of the line) will
+ * be drawn at the current point of the cairo context.
+ *
+ * Since: 1.10
+ **/
+void
+pango_cairo_show_layout_line (cairo_t          *cr,
+			      PangoLayoutLine  *line)
+{
+  PangoContext *context;
+  PangoFontMap *fontmap;
+  PangoRenderer *renderer;
+  PangoCairoRenderer *crenderer;
+
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (line != NULL);
+
+  context = pango_layout_get_context (line->layout);
+  fontmap = pango_context_get_font_map (context);
+  renderer = _pango_cairo_font_map_get_renderer (PANGO_CAIRO_FONT_MAP (fontmap));
+  crenderer = PANGO_CAIRO_RENDERER (renderer);
+
+  cairo_save (cr);
+  current_point_to_origin (cr);
+
+  crenderer->cr = cr;
+  pango_renderer_draw_layout_line (renderer, line, 0, 0);
+  crenderer->cr = NULL;
+  
+  cairo_restore (cr);
+}
+
+/**
+ * pango_cairo_show_layout:
+ * @cr: a Cairo context
+ * @layout: a Pango layout
+ * 
+ * Draws a #PangoLayoutLine in the specified cairo context.
+ * The top-left corner of the #PangoLayout will be drawn
+ * at the current point of the cairo context.
+ *
+ * Since: 1.10
+ **/
+void
+pango_cairo_show_layout (cairo_t     *cr,
+			 PangoLayout *layout)
+{
+  PangoContext *context;
+  PangoFontMap *fontmap;
+  PangoRenderer *renderer;
+  PangoCairoRenderer *crenderer;
+
+  g_return_if_fail (cr != NULL);
+  g_return_if_fail (PANGO_IS_LAYOUT (layout));
+
+  context = pango_layout_get_context (layout);
+  fontmap = pango_context_get_font_map (context);
+  renderer = _pango_cairo_font_map_get_renderer (PANGO_CAIRO_FONT_MAP (fontmap));
+  crenderer = PANGO_CAIRO_RENDERER (renderer);
+  
+  cairo_save (cr);
+  current_point_to_origin (cr);
+
+  crenderer->cr = cr;
+  pango_renderer_draw_layout (renderer, layout, 0, 0);
+  crenderer->cr = NULL;
+  
+  cairo_restore (cr);
+}