gpu_get_blendmode_destalpha


Description

This function can be used to retrieve the current destination extended blend mode alpha factor. The value returned will be one of the following constants ("s" denotes a value taken from the source while a "d" denotes a value from the destination) with only the "A" component being used when drawing:

Constant Blend factor (Red, Green, Blue, Alpha)
bm_zero (0, 0, 0, 0)
bm_one (1, 1, 1, 1)
bm_src_colour (Rs, Gs, Bs, As)
bm_inv_src_colour (1-Rs, 1-Gs, 1-Bs, 1-As)
bm_src_alpha (As, As, As, As)
bm_inv_src_alpha (1-As, 1-As, 1-As, 1-As)
bm_dest_alpha (Ad, Ad, Ad, Ad)
bm_inv_dest_alpha (1-Ad, 1-Ad, 1-Ad, 1-Ad)
bm_dest_colour (Rd, Gd, Bd, Ad)
bm_inv_dest_colour (1-Rd, 1-Gd, 1-Bd, 1-Ad)
bm_src_alpha_sat (f, f, f, 1) where f = min(As, 1-Ad)


Syntax:

gpu_get_blendmode_destalpha();


Returns:

Constant (see above table)


Example:

var bm;
bm[0] = gpu_get_blendmode_srcalpha();
bm[1] = gpu_get_blendmode_destalpha();
gpu_set_blendmode_ext_sepalpha(bm_inv_src_alpha, bm_inv_dest_colour, bm[0], bm[1]);

The above code creates a local array and gets the current source and destination blending factors for the alpha component. This array is then used to manipulate the RGB component of the blending factors.


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