GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: gx_display_driver_1555xrgb_pixel_blend.c Lines: 20 20 100.0 %
Date: 2024-12-05 08:52:37 Branches: 4 4 100.0 %

Line Branch Exec Source
1
/***************************************************************************
2
 * Copyright (c) 2024 Microsoft Corporation
3
 *
4
 * This program and the accompanying materials are made available under the
5
 * terms of the MIT License which is available at
6
 * https://opensource.org/licenses/MIT.
7
 *
8
 * SPDX-License-Identifier: MIT
9
 **************************************************************************/
10
11
12
/**************************************************************************/
13
/**************************************************************************/
14
/**                                                                       */
15
/** GUIX Component                                                        */
16
/**                                                                       */
17
/**   Display Management (Display)                                        */
18
/**                                                                       */
19
/**************************************************************************/
20
21
#define _COLOR_FORMAT_ 1555xrgb
22
#define PIXEL_LOC      USHORT
23
24
#define REDVAL(_c)     (GX_UBYTE)(((_c) >> 10) & 0x1f)
25
#define GREENVAL(_c)   (GX_UBYTE)(((_c) >> 5) & 0x1f)
26
#define BLUEVAL(_c)    (GX_UBYTE)(((_c)) & 0x1f)
27
28
#define ASSEMBLECOLOR(_r, _g, _b) \
29
    ((((_r) & 0x7c) << 10) |      \
30
     (((_g) & 0x3e) << 5) |       \
31
     (((_b) & 0x1f)))
32
33
#define GX_SOURCE_CODE
34
35
36
/* Include necessary system files.  */
37
38
#include "gx_api.h"
39
#include "gx_display.h"
40
41
/**************************************************************************/
42
/*                                                                        */
43
/*  FUNCTION                                               RELEASE        */
44
/*                                                                        */
45
/*    _gx_display_driver_1555xrgb_pixel_blend            PORTABLE C       */
46
/*                                                           6.1          */
47
/*  AUTHOR                                                                */
48
/*                                                                        */
49
/*    Kenneth Maxwell, Microsoft Corporation                              */
50
/*                                                                        */
51
/*  DESCRIPTION                                                           */
52
/*                                                                        */
53
/*    Pixel blend function for 1555xrgb color format.                     */
54
/*                                                                        */
55
/*  INPUT                                                                 */
56
/*                                                                        */
57
/*    context                               Drawing context               */
58
/*    x                                     X coordinate                  */
59
/*    y                                     Y coordinate                  */
60
/*    color                                 Color of line to write        */
61
/*    alpha                                 Alpha value                   */
62
/*                                                                        */
63
/*  OUTPUT                                                                */
64
/*                                                                        */
65
/*    None                                                                */
66
/*                                                                        */
67
/*  CALLS                                                                 */
68
/*                                                                        */
69
/*    REDVAL                                Extract the red component     */
70
/*    GREENVAL                              Extract the green component   */
71
/*    BLUEVAL                               Extract the blue component    */
72
/*    ASSEMBLECOLOR                         Assemble color components     */
73
/*                                                                        */
74
/*  CALLED BY                                                             */
75
/*                                                                        */
76
/*    GUIX Internal Code                                                  */
77
/*                                                                        */
78
/*  RELEASE HISTORY                                                       */
79
/*                                                                        */
80
/*    DATE              NAME                      DESCRIPTION             */
81
/*                                                                        */
82
/*  05-19-2020     Kenneth Maxwell          Initial Version 6.0           */
83
/*  09-30-2020     Kenneth Maxwell          Modified comment(s),          */
84
/*                                            resulting in version 6.1    */
85
/*                                                                        */
86
/**************************************************************************/
87
111081827
VOID _gx_display_driver_1555xrgb_pixel_blend(GX_DRAW_CONTEXT *context, INT x, INT y, GX_COLOR fcolor, GX_UBYTE alpha)
88
{
89
GX_UBYTE fred, fgreen, fblue;
90
GX_UBYTE bred, bgreen, bblue;
91
GX_UBYTE balpha;
92
93
USHORT   bcolor;
94
USHORT  *put;
95
96
97
    /* Is the pixel non-transparent? */
98
111081827
    if (alpha > 0)
99
    {
100
        /* calculate address of pixel */
101
71790891
        put = (USHORT *)context -> gx_draw_context_memory;
102
71790891
        put += context -> gx_draw_context_pitch * y;
103
71790891
        put += x;
104
105
        /* No need to blend if alpha value is 255. */
106
71790891
        if (alpha == 255)
107
        {
108
62367422
            *put = (USHORT)fcolor;
109
62367422
            return;
110
        }
111
112
        /* split foreground into red, green, and blue components */
113
9423469
        fred = REDVAL(fcolor);
114
9423469
        fgreen = GREENVAL(fcolor);
115
9423469
        fblue = BLUEVAL(fcolor);
116
117
        /* read background color */
118
9423469
        bcolor = *put;
119
120
        /* split background color into red, green, and blue components */
121
9423469
        bred = REDVAL(bcolor);
122
9423469
        bgreen = GREENVAL(bcolor);
123
9423469
        bblue = BLUEVAL(bcolor);
124
125
        /* background alpha is inverse of foreground alpha */
126
9423469
        balpha = (GX_UBYTE)(256 - alpha);
127
128
        /* blend foreground and background, each color channel */
129
9423469
        fred = (GX_UBYTE)(((bred * balpha) + (fred * alpha)) >> 8);
130
9423469
        fgreen = (GX_UBYTE)(((bgreen * balpha) + (fgreen * alpha)) >> 8);
131
9423469
        fblue = (GX_UBYTE)(((bblue * balpha) + (fblue * alpha)) >> 8);
132
133
        /* re-assemble into 16-bit color and write it out */
134
9423469
        *put = (USHORT)ASSEMBLECOLOR(fred, fgreen, fblue);
135
    }
136
}
137