hvif-light/src/hvif-cairo.c

#include "hvif-light.h"

#include <stdint.h>
#include <assert.h>
#include <cairo.h>

#define INTERNAL_DATASTRUCTURES
#include "hvif-light.c"
#undef INTERNAL_DATASTRUCTURES

/* TODO:
 * 	1. Draw the path in each shape as outline
 *  2. Then do the same for the styles
 *  3. Put everything together
 */

void
create_path(cairo_t* cr, hvif_path* path)
{
	assert(path->num_points > 0);

	for (unsigned i = 0; i < path->num_points; ++i) {
		hvif_point p = path->points[3 * i];
		hvif_point cp1 = path->points[3 * i + 1];
		hvif_point cp2 = path->points[3 * i + 2];
		cairo_curve_to(cr, cp1.x, cp1.y, cp2.x, cp2.y, p.x, p.y);
	}

	if (path->closed)
		cairo_close_path(cr);
}

bool
hvif_render_image(const char* filename, hvif_image* image)
{
	cairo_surface_t* surface =
		cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 254, 254);
	cairo_t* cr = cairo_create(surface);
	cairo_scale(cr, 4.0, 4.0);

	cairo_set_line_width(cr, 0.2);

	double r = 0;
	double delta = 1.0 / image->num_shapes;

	for (unsigned i = 0; i < image->num_shapes; ++i) {
		cairo_set_source_rgb(cr, r, 0, 0);
		r = r + delta;
		hvif_shape s = image->shapes[i];
		if (s.hinting)
			printf("shape %u has hinting\n", i);
		else
			printf("shape %u has no hinting\n", i);
		for (unsigned j = 0; j < s.num_paths; ++j) {
			hvif_path* p = &image->paths[s.path_idxs[j]];
			create_path(cr, p);
			cairo_stroke(cr);
		}
	}

	cairo_destroy(cr);

	bool result = true;
	if (cairo_surface_write_to_png(surface, filename) != CAIRO_STATUS_SUCCESS)
		result = false;
	cairo_surface_destroy(surface);
	return result;
}