/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation 
 * 
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 * 
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** GUIX Component                                                        */
/**                                                                       */
/**   Canvas Management (Canvas)                                          */
/**                                                                       */
/**************************************************************************/

#define GX_SOURCE_CODE


/* Include necessary system files.  */

#include "gx_api.h"
#include "gx_system.h"
#include "gx_utility.h"
#include "gx_canvas.h"


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _gx_canvas_alpha_set                                PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Kenneth Maxwell, Microsoft Corporation                              */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function assigns the alpha-blend value of a canvas             */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    canvas                                Canvas control block          */
/*    alpha                                 alpha value                   */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _gx_canvas_dirty_mark                 Set the canvas dirty flag     */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    _gx_animation_start                                                 */
/*    _gx_animation_update                                                */
/*                                                                        */
/*  RELEASE HISTORY                                                       */
/*                                                                        */
/*    DATE              NAME                      DESCRIPTION             */
/*                                                                        */
/*  05-19-2020     Kenneth Maxwell          Initial Version 6.0           */
/*  09-30-2020     Kenneth Maxwell          Modified comment(s),          */
/*                                            resulting in version 6.1    */
/*                                                                        */
/**************************************************************************/
UINT  _gx_canvas_alpha_set(GX_CANVAS *canvas, GX_UBYTE alpha)
{
VOID (*alpha_set)(INT layer, GX_UBYTE alpha);

    /* change the alpha value */
    canvas -> gx_canvas_alpha = alpha;

    if (canvas -> gx_canvas_hardware_layer >= 0)
    {
        alpha_set = canvas -> gx_canvas_display -> gx_display_layer_services -> gx_display_layer_alpha_set;

        if (alpha_set)
        {
            alpha_set(canvas -> gx_canvas_hardware_layer, alpha);
            return(GX_SUCCESS);
        }
    }

    /* mark the canvas dirty so that it get refreshed */
    _gx_canvas_dirty_mark(canvas, GX_NULL);

    /* Return successful status.  */
    return(GX_SUCCESS);
}