Mesh pattern demo

mesh_pattern.c

/* Mesh pattern demo - requires Cairo 1.12
 * Compile with:
 *   gcc -I/usr/include/cairo -o mesh_pattern mesh_pattern.c -lcairo
 *   (or similar)
 *
 * Running will create 'mesh.png' in the current directory
 * Michael Maclean <michael@no-surprises.co.uk>
 */

#include <cairo.h>

int main(int argc, char **argv) {
	cairo_t *ctx;
	cairo_surface_t *surface;
	cairo_pattern_t *pattern;

	/* Create a 400x300px image surface, using 24-bit colour */
	surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, 400, 300);

	/* Create a context to do the drawing with */
	ctx = cairo_create(surface);
	
	/* Create our pattern */
	pattern = cairo_pattern_create_mesh();

	/* Use the mesh pattern functions to create a square (called a 'patch')
	 * This square will be the same size as the image */
	cairo_mesh_pattern_begin_patch(pattern);
	cairo_mesh_pattern_line_to(pattern, 0, 0);  /* Corner 0 */
	cairo_mesh_pattern_line_to(pattern, 400, 0); /* Corner 1 */
	cairo_mesh_pattern_line_to(pattern, 400, 300); /* Corner 2 */
	cairo_mesh_pattern_line_to(pattern, 0, 300); /* Corner 3 */
	cairo_mesh_pattern_line_to(pattern, 0, 0);  /* Back to corner 0 */

	/* Assign colours to each corner */
	cairo_mesh_pattern_set_corner_color_rgb(pattern, 0, 0, 0, 0); /* Corner 0 - black */
	cairo_mesh_pattern_set_corner_color_rgb(pattern, 1, 1, 0, 0); /* Corner 1 - red */
	cairo_mesh_pattern_set_corner_color_rgb(pattern, 2, 0, 1, 0); /* Corner 2 - green */
	cairo_mesh_pattern_set_corner_color_rgb(pattern, 3, 0, 0, 1); /* Corner 2 - blue */

	/* Finish the pattern */
	cairo_mesh_pattern_end_patch(pattern);

	/* Set the context to use the pattern for drawing */
	cairo_set_source(ctx, pattern);

	/* Draw a rectange and fill it */
	cairo_rectangle(ctx, 0, 0, 400, 300);
	cairo_fill(ctx);

	/* Write the resulting image to a PNG */
	cairo_surface_write_to_png(surface, "mesh.png");
}