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 GX_SOURCE_CODE
22
23 /* Include necessary system files. */
24
25 #include "gx_api.h"
26 #include "gx_display.h"
27
28 /**************************************************************************/
29 /* */
30 /* FUNCTION RELEASE */
31 /* */
32 /* _gx_display_driver_4bpp_horizontal_line_draw PORTABLE C */
33 /* 6.1 */
34 /* AUTHOR */
35 /* */
36 /* Kenneth Maxwell, Microsoft Corporation */
37 /* */
38 /* DESCRIPTION */
39 /* */
40 /* Horizontal line draw function for 4bpp display driver. */
41 /* */
42 /* INPUT */
43 /* */
44 /* context Drawing context */
45 /* xstart x-coord of left endpoint */
46 /* xend x-coord of right endpoint */
47 /* ypos y-coord of line top */
48 /* width Width (height) of the line */
49 /* color Color of line to write */
50 /* */
51 /* OUTPUT */
52 /* */
53 /* None */
54 /* */
55 /* CALLS */
56 /* */
57 /* None */
58 /* */
59 /* CALLED BY */
60 /* */
61 /* GUIX Internal Code */
62 /* */
63 /* RELEASE HISTORY */
64 /* */
65 /* DATE NAME DESCRIPTION */
66 /* */
67 /* 05-19-2020 Kenneth Maxwell Initial Version 6.0 */
68 /* 09-30-2020 Kenneth Maxwell Modified comment(s), */
69 /* resulting in version 6.1 */
70 /* */
71 /**************************************************************************/
_gx_display_driver_4bpp_horizontal_line_draw(GX_DRAW_CONTEXT * context,INT xstart,INT xend,INT ypos,INT width,GX_COLOR color)72 VOID _gx_display_driver_4bpp_horizontal_line_draw(GX_DRAW_CONTEXT *context, INT xstart, INT xend, INT ypos, INT width, GX_COLOR color)
73 {
74 INT row;
75 INT column;
76 GX_UBYTE *put;
77 GX_UBYTE *putrow;
78 GX_UBYTE mask;
79 GX_UBYTE pixel;
80 INT stride;
81
82 /* Get row pitch in bytes. */
83 stride = (context -> gx_draw_context_pitch + 1) >> 1;
84 pixel = (GX_UBYTE)(color & 0x0f);
85 pixel |= (GX_UBYTE)(pixel << 4);
86
87 /* pick up start address of canvas memory */
88 putrow = (GX_UBYTE *)context -> gx_draw_context_memory;
89 putrow += ypos * stride;
90 putrow += (xstart >> 1);
91
92 for (row = 0; row < width; row++)
93 {
94 put = putrow;
95
96 if (xstart & 0x01)
97 {
98 mask = 0x0f;
99 }
100 else
101 {
102 mask = 0xf0;
103 }
104
105 column = xstart;
106 while (column <= xend)
107 {
108 if ((mask == 0xf0) && (xend - column) > 2)
109 {
110 while ((xend - column) > 2)
111 {
112 *put++ = pixel;
113 column += 2;
114 }
115 }
116 else
117 {
118 /*Set bits first.*/
119 *put &= (GX_UBYTE)(~mask);
120 *put |= (GX_UBYTE)(pixel & mask);
121 mask >>= 4;
122
123 if (mask == 0)
124 {
125 mask = 0xf0;
126 put++;
127 }
128 column++;
129 }
130 }
131 putrow += stride;
132 }
133 }
134
135
