From a716de927edbe4aaeb2025c6f11d988ca3ee05b9 Mon Sep 17 00:00:00 2001
From: Thomas White <taw@bitwiz.me.uk>
Date: Sat, 23 Feb 2019 10:22:26 +0100
Subject: Unformatted text rendering

---
 libstorycode/slide.c              |  1 +
 libstorycode/slide_priv.h         | 10 ++++++
 libstorycode/slide_render_cairo.c | 66 +++++++++++++++++++++++++++++++++++----
 libstorycode/storycode.h          |  8 +++++
 meson.build                       |  3 ++
 5 files changed, 82 insertions(+), 6 deletions(-)

diff --git a/libstorycode/slide.c b/libstorycode/slide.c
index 9ce0930..ca40347 100644
--- a/libstorycode/slide.c
+++ b/libstorycode/slide.c
@@ -111,6 +111,7 @@ int slide_add_text(Slide *s, char **text, int n_text, struct frame_geom geom)
 	item->n_paras = n_text;
 
 	item->geom = geom;
+	item->align = ALIGN_LEFT;
 
 	return 0;
 }
diff --git a/libstorycode/slide_priv.h b/libstorycode/slide_priv.h
index 65d2459..fb535ba 100644
--- a/libstorycode/slide_priv.h
+++ b/libstorycode/slide_priv.h
@@ -23,6 +23,12 @@
 #ifndef SLIDE_PRIV_H
 #define SLIDE_PRIV_H
 
+#ifdef HAVE_PANGO
+#include <pango/pangocairo.h>
+#endif
+
+#include "storycode.h"
+
 enum slide_item_type
 {
 	SLIDE_ITEM_TEXT,
@@ -40,6 +46,10 @@ struct slide_item
 	/* For TEXT */
 	char **paragraphs;
 	int n_paras;
+	enum alignment align;
+#ifdef HAVE_PANGO
+	PangoLayout **layouts;
+#endif
 
 	/* For IMAGE */
 	char *filename;
diff --git a/libstorycode/slide_render_cairo.c b/libstorycode/slide_render_cairo.c
index e701aed..8e1eeba 100644
--- a/libstorycode/slide_render_cairo.c
+++ b/libstorycode/slide_render_cairo.c
@@ -50,16 +50,69 @@ static double lcalc(struct length l, double pd)
 }
 
 
-static void render_text(struct slide_item *item, cairo_t *cr,
+static PangoAlignment to_pangoalignment(enum alignment align)
+{
+	switch ( align ) {
+		case ALIGN_LEFT : return PANGO_ALIGN_LEFT;
+		case ALIGN_RIGHT : return PANGO_ALIGN_RIGHT;
+		case ALIGN_CENTER : return PANGO_ALIGN_CENTER;
+		default: return PANGO_ALIGN_LEFT;
+	}
+}
+
+
+static void render_text(struct slide_item *item, cairo_t *cr, PangoContext *pc,
                         double parent_w, double parent_h)
 {
-	cairo_rectangle(cr, lcalc(item->geom.x, parent_w),
-	                    lcalc(item->geom.y, parent_h),
-	                    lcalc(item->geom.w, parent_w),
-	                    lcalc(item->geom.h, parent_h));
+	int i;
+	double x, y, w, h;
+	PangoRectangle rect;
+
+	x = lcalc(item->geom.x, parent_w);
+	y = lcalc(item->geom.y, parent_h);
+	w = lcalc(item->geom.w, parent_w);
+	h = lcalc(item->geom.h, parent_h);
+
+	cairo_rectangle(cr, x, y, w, h);
 	cairo_set_source_rgb(cr, 0.0, 0.0, 0.0);
 	cairo_set_line_width(cr, 1.0);
 	cairo_stroke(cr);
+
+	if ( item->layouts == NULL ) {
+		item->layouts = malloc(item->n_paras*sizeof(PangoLayout *));
+		if ( item->layouts == NULL ) return;
+		for ( i=0; i<item->n_paras; i++ ) {
+			item->layouts[i] = NULL;
+		}
+	}
+
+	for ( i=0; i<item->n_paras; i++ ) {
+
+		if ( item->layouts[i] == NULL ) {
+			item->layouts[i] = pango_layout_new(pc);
+		}
+		pango_layout_set_width(item->layouts[i],
+		                       pango_units_from_double(w));
+		pango_layout_set_text(item->layouts[i], item->paragraphs[i], -1);
+
+		pango_layout_set_alignment(item->layouts[i],
+		                           to_pangoalignment(item->align));
+
+		/* FIXME: Handle *bold*, _underline_, /italic/ etc. */
+		//pango_layout_set_attributes(item->layouts[i], attrs);
+		//pango_attr_list_unref(attrs);
+
+		cairo_save(cr);
+		cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+		cairo_translate(cr, x, y);
+		pango_cairo_update_layout(cr, item->layouts[i]);
+		pango_cairo_show_layout(cr, item->layouts[i]);
+		pango_layout_get_extents(item->layouts[i], NULL, &rect);
+		y += pango_units_to_double(rect.height);
+		cairo_fill(cr);
+		cairo_restore(cr);
+
+	}
 }
 
 
@@ -93,7 +146,8 @@ int slide_render_cairo(Slide *s, cairo_t *cr, Stylesheet *stylesheet,
 		switch ( s->items[i].type ) {
 
 			case SLIDE_ITEM_TEXT :
-			render_text(&s->items[i], cr, s->logical_w, s->logical_h);
+			render_text(&s->items[i], cr, pc,
+			            s->logical_w, s->logical_h);
 			break;
 
 			case SLIDE_ITEM_IMAGE :
diff --git a/libstorycode/storycode.h b/libstorycode/storycode.h
index 476941e..6e07a3b 100644
--- a/libstorycode/storycode.h
+++ b/libstorycode/storycode.h
@@ -29,6 +29,14 @@
 
 #include "presentation.h"
 
+enum alignment
+{
+	ALIGN_LEFT,
+	ALIGN_RIGHT,
+	ALIGN_CENTER
+};
+
+
 extern Presentation *storycode_parse_presentation(const char *sc);
 
 
diff --git a/meson.build b/meson.build
index 2f05a81..814da89 100644
--- a/meson.build
+++ b/meson.build
@@ -28,6 +28,9 @@ pangocairo_dep = dependency('pangocairo', required : true)
 gdkpixbuf_dep = dependency('gdk-pixbuf-2.0', required : true)
 cc = meson.get_compiler('c')
 
+if pangocairo_dep.found()
+  add_project_arguments('-DHAVE_PANGO', language : 'c')
+endif
 
 # Compiled-in resources
 gresources = gnome.compile_resources('colloquium-resources',
-- 
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