conky/lua/cairo_imlib2_helper.pkg

$#include <cairo.h>
$#include <libcairo_imlib2_helper.h>

/* Paints the image onto the cairo_surface_t */
void cairo_draw_image(const char *, cairo_surface_t *, int, int,
                      double scale_x=1.0, double scale_y=1.0,
                      double * return_scale_w, double * return_scale_h);

/* Places an image onto a cairo_t but doesn't call cairo_paint */
void cairo_place_image(const char *file, cairo_t *cr, int x, int y,
                       int width, int height, double alpha=1.0);
Wrapper for drawing images with imlib2 and cairo One problem is, that tolua/lua does not handle plain data pointers properly. Therefore something like local surface = cairo_image_surface_create_for_data( imlib_image_get_data_for_reading_only(), .. will fail using the lua bindings. Hence this wrapper, which adds a function which be used to draw an imlib image to a cairo surface. This also addresses another issue, drawing images with a transparent background (e.g. gifs or pngs) to the cairo surface properly. Apparently the image format of imlib is incompatible to cairos which uses pre-multiplied data. This is also explained in the cairo documentation. A fix for this issue is to blend the image with another alpha mask to get the correct values. The code and explanation for this was taken from http://lists.cairographics.org/archives/cairo/2008-March/013492.html Executive Summary: This wrapper function can load (transparent) images (e.g. gif or png) from a file by using imlib and draw them on a cairo surface. 2013-06-08 09:51:14 +00:00			`$#include <cairo.h>`
			`$#include <libcairo_imlib2_helper.h>`

Split cairo_draw_image into two functions In some cases you are already working with a cairo_t and know your destination image size, this adds an API that allows you to handle these cases more easily. Along with now being able to draw images with an alpha level. It also leaves the original API unchanged. 2024-02-26 09:17:00 +00:00			`/* Paints the image onto the cairo_surface_t */`
			`void cairo_draw_image(const char , cairo_surface_t , int, int,`
			`double scale_x=1.0, double scale_y=1.0,`
Wrapper for drawing images with imlib2 and cairo One problem is, that tolua/lua does not handle plain data pointers properly. Therefore something like local surface = cairo_image_surface_create_for_data( imlib_image_get_data_for_reading_only(), .. will fail using the lua bindings. Hence this wrapper, which adds a function which be used to draw an imlib image to a cairo surface. This also addresses another issue, drawing images with a transparent background (e.g. gifs or pngs) to the cairo surface properly. Apparently the image format of imlib is incompatible to cairos which uses pre-multiplied data. This is also explained in the cairo documentation. A fix for this issue is to blend the image with another alpha mask to get the correct values. The code and explanation for this was taken from http://lists.cairographics.org/archives/cairo/2008-March/013492.html Executive Summary: This wrapper function can load (transparent) images (e.g. gif or png) from a file by using imlib and draw them on a cairo surface. 2013-06-08 09:51:14 +00:00			`double * return_scale_w, double * return_scale_h);`
Split cairo_draw_image into two functions In some cases you are already working with a cairo_t and know your destination image size, this adds an API that allows you to handle these cases more easily. Along with now being able to draw images with an alpha level. It also leaves the original API unchanged. 2024-02-26 09:17:00 +00:00
			`/* Places an image onto a cairo_t but doesn't call cairo_paint */`
			`void cairo_place_image(const char file, cairo_t cr, int x, int y,`
			`int width, int height, double alpha=1.0);`