Rendering stuff

1 files changed, 202 insertions, 0 deletions

diff --git a/src/render.c b/src/render.c
new file mode 100644
index 0000000..1e8a697
--- /dev/null
+++ b/src/render.c
@@ -0,0 +1,202 @@
+/*
+ * render.c
+ *
+ * Colloquium - A tiny presentation program
+ *
+ * Copyright (c) 2011 Thomas White <taw@bitwiz.org.uk>
+ *
+ * This program 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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/>.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cairo.h>
+#include <cairo-pdf.h>
+#include <pango/pangocairo.h>
+#include <assert.h>
+#include <gdk/gdk.h>
+
+#include "storycode.h"
+#include "stylesheet.h"
+#include "presentation.h"
+
+
+static void render_bgblock(cairo_t *cr, struct bgblock *b)
+{
+	GdkColor col1;
+	GdkColor col2;
+	cairo_pattern_t *patt = NULL;
+	double cx, cy, r, r1, r2;
+
+	cairo_rectangle(cr, b->min_x, b->min_y,
+	                    b->max_x - b->min_x,
+	                    b->max_y - b->min_y);
+
+	switch ( b->type ) {
+
+		case BGBLOCK_SOLID :
+		gdk_color_parse(b->colour1, &col1);
+		gdk_cairo_set_source_color(cr, &col1);
+		/* FIXME: Honour alpha as well */
+		cairo_fill(cr);
+		break;
+
+		case BGBLOCK_GRADIENT_CIRCULAR :
+		cx = b->min_x + (b->max_x-b->min_x)/2.0;
+		cy = b->min_y + (b->max_y-b->min_y)/2.0;
+		r1 = (b->max_x-b->min_x)/2.0;
+		r2 = (b->max_y-b->min_y)/2.0;
+		r = r1 > r2 ? r1 : r2;
+		patt = cairo_pattern_create_radial(cx, cy, r, cx, cy, 0.0);
+		/* Fall-through */
+
+		case BGBLOCK_GRADIENT_X :
+		if ( patt == NULL ) {
+			patt = cairo_pattern_create_linear(b->min_x, 0.0,
+		                                           b->max_y, 0.0);
+		}
+		/* Fall-through */
+
+		case BGBLOCK_GRADIENT_Y :
+		if ( patt == NULL ) {
+			patt = cairo_pattern_create_linear(0.0, b->min_y,
+		                                           0.0, b->max_y);
+		}
+
+		gdk_color_parse(b->colour1, &col1);
+		gdk_color_parse(b->colour2, &col2);
+		cairo_pattern_add_color_stop_rgba(patt, 0.0, col1.red/65535.0,
+		                                             col1.green/65535.0,
+		                                             col1.blue/65535.0,
+		                                             b->alpha1);
+		cairo_pattern_add_color_stop_rgba(patt, 1.0, col2.red/65535.0,
+		                                             col2.green/65535.0,
+		                                             col2.blue/65535.0,
+		                                             b->alpha2);
+		cairo_set_source(cr, patt);
+		cairo_fill(cr);
+		cairo_pattern_destroy(patt);
+		break;
+
+		case BGBLOCK_IMAGE :
+		cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
+		cairo_fill(cr);
+
+	}
+}
+
+
+/* Render Level 1 Storycode */
+int render_sc(const char *sc, cairo_t *cr, double w, double h, PangoContext *pc)
+{
+	PangoLayout *layout;
+	PangoFontDescription *fontdesc;
+	GdkColor col;
+
+	/* FIXME: Check for Level 1 markup e.g. image */
+
+	layout = pango_layout_new(pc);
+
+	pango_cairo_update_layout(cr, layout);
+	pango_layout_set_width(layout, w*PANGO_SCALE);
+	pango_layout_set_height(layout, h*PANGO_SCALE);
+
+	pango_layout_set_text(layout, sc, -1);
+	fontdesc = pango_font_description_from_string("Sans 12");
+
+	pango_layout_set_font_description(layout, fontdesc);
+
+	cairo_move_to(cr, 0.0, 0.0);
+
+	/* FIXME: Honour alpha as well */
+	gdk_color_parse("#000000", &col);
+	gdk_cairo_set_source_color(cr, &col);
+
+	pango_cairo_show_layout(cr, layout);
+
+	pango_font_description_free(fontdesc);
+	g_object_unref(G_OBJECT(layout));
+
+	return 0;
+}
+
+
+static int render_frame(struct frame *fr, cairo_t *cr, double w, double h)
+{
+	int i;
+
+	/* The rendering order is a list of children, but it also contains the
+	 * current frame.  In this way, it contains information about which
+	 * layer the current frame is to be rendered as relative to its
+	 * children. */
+	for ( i=0; i<fr->num_ro; i++ ) {
+
+		double nw, nh;
+
+		if ( fr->rendering_order[i] == fr ) {
+			render_sc(fr->sc, cr, w, h, fr->pc);
+			continue;
+		}
+
+		/* Sort out the transformation for the margins */
+		cairo_translate(cr, fr->rendering_order[i]->cl->margin_left,
+		                    fr->rendering_order[i]->cl->margin_top);
+
+		nw = w - fr->rendering_order[i]->cl->margin_left;
+		nw    -= fr->rendering_order[i]->cl->margin_right;
+
+		nh = h - fr->rendering_order[i]->cl->margin_top;
+		nh    -= fr->rendering_order[i]->cl->margin_bottom;
+
+		render_frame(fr->rendering_order[i], cr, nw, nh);
+
+	}
+
+	return 0;
+}
+
+
+cairo_surface_t *render_slide(struct slide *s, int w, int h)
+{
+	cairo_surface_t *surf;
+	cairo_t *cr;
+	cairo_font_options_t *fopts;
+	int i;
+
+	surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
+
+	cr = cairo_create(surf);
+	cairo_scale(cr, w, h);
+
+	fopts = cairo_font_options_create();
+	cairo_font_options_set_hint_style(fopts, CAIRO_HINT_STYLE_NONE);
+	cairo_font_options_set_hint_metrics(fopts, CAIRO_HINT_METRICS_OFF);
+	cairo_font_options_set_antialias(fopts, CAIRO_ANTIALIAS_SUBPIXEL);
+	cairo_set_font_options(cr, fopts);
+
+	for ( i=0; i<s->st->n_bgblocks; i++ ) {
+		render_bgblock(cr, s->st->bgblocks[i]);
+	}
+
+	render_frame(s->top, cr, w, h);
+
+	cairo_font_options_destroy(fopts);
+	cairo_destroy(cr);
+
+	return surf;
+}