Image Surfaces Cairo: A Vector Graphics Library Top | Description Image Surfaces Image Surfaces — Rendering to memory buffers Synopsis enum cairo_format_t; cairo_surface_t* cairo_image_surface_create (cairo_format_t format, int width, int height); cairo_surface_t* cairo_image_surface_create_for_data (unsigned char *data, cairo_format_t format, int width, int height, int stride); unsigned char* cairo_image_surface_get_data (cairo_surface_t *surface); cairo_format_t cairo_image_surface_get_format (cairo_surface_t *surface); int cairo_image_surface_get_width (cairo_surface_t *surface); int cairo_image_surface_get_height (cairo_surface_t *surface); int cairo_image_surface_get_stride (cairo_surface_t *surface); Description Image surfaces provide the ability to render to memory buffers either allocated by cairo or by the calling code. The supported image formats are those defined in cairo_format_t. Details enum cairo_format_t typedef enum _cairo_format { CAIRO_FORMAT_ARGB32, CAIRO_FORMAT_RGB24, CAIRO_FORMAT_A8, CAIRO_FORMAT_A1, CAIRO_FORMAT_RGB16_565 } cairo_format_t; cairo_format_t is used to identify the memory format of image data. CAIRO_FORMAT_ARGB32 each pixel is a 32-bit quantity, with alpha in the upper 8 bits, then red, then green, then blue. The 32-bit quantities are stored native-endian. Pre-multiplied alpha is used. (That is, 50% transparent red is 0x80800000, not 0x80ff0000.) CAIRO_FORMAT_RGB24 each pixel is a 32-bit quantity, with the upper 8 bits unused. Red, Green, and Blue are stored in the remaining 24 bits in that order. CAIRO_FORMAT_A8 each pixel is a 8-bit quantity holding an alpha value. CAIRO_FORMAT_A1 each pixel is a 1-bit quantity holding an alpha value. Pixels are packed together into 32-bit quantities. The ordering of the bits matches the endianess of the platform. On a big-endian machine, the first pixel is in the uppermost bit, on a little-endian machine the first pixel is in the least-significant bit. CAIRO_FORMAT_RGB16_565 each pixel is a 16-bit quantity, with red in the upper 5 bits, then green in the next 6, then blue in the lowest 5 bits. (Since 1.2) cairo_image_surface_create () cairo_surface_t* cairo_image_surface_create (cairo_format_t format, int width, int height); cairo_image_surface_create_for_data () cairo_surface_t* cairo_image_surface_create_for_data (unsigned char *data, cairo_format_t format, int width, int height, int stride); cairo_image_surface_get_data () unsigned char* cairo_image_surface_get_data (cairo_surface_t *surface); Since 1.2 cairo_image_surface_get_format () cairo_format_t cairo_image_surface_get_format (cairo_surface_t *surface); Since 1.2 cairo_image_surface_get_width () int cairo_image_surface_get_width (cairo_surface_t *surface); cairo_image_surface_get_height () int cairo_image_surface_get_height (cairo_surface_t *surface); cairo_image_surface_get_stride () int cairo_image_surface_get_stride (cairo_surface_t *surface); Since 1.2
