.\" Generated by the Allegro makedoc utility .TH set_write_alpha_blender 3alleg4 "version 4.4.3" "Allegro" "Allegro manual" .SH NAME set_write_alpha_blender \- Enables the special alpha-channel editing mode. Allegro game programming library.\& .SH SYNOPSIS .B #include .sp .B void set_write_alpha_blender(); .SH DESCRIPTION Enables the special alpha-channel editing mode, which is used for drawing alpha channels over the top of an existing 32-bit RGB sprite, to turn it into an RGBA format image. After calling this function, you can set the drawing mode to DRAW_MODE_TRANS and then write draw color values (0-255) onto a 32-bit image. This will leave the color values unchanged, but alter the alpha to whatever values you are writing. After enabling this mode you can also use draw_trans_sprite() to superimpose an 8-bit alpha mask over the top of an existing 32-bit sprite. .SH SEE ALSO .BR set_alpha_blender (3alleg4), .BR draw_trans_sprite (3alleg4), .BR drawing_mode (3alleg4), .BR exalpha (3alleg4), .BR extrans (3alleg4)