1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** GUIX Component */
17 /** */
18 /** Display Management (Display) */
19 /** */
20 /**************************************************************************/
21
22 #define GX_SOURCE_CODE
23
24
25 /* Include necessary system files. */
26
27 #include "gx_api.h"
28 #include "gx_display.h"
29
30
31 /**************************************************************************/
32 /* */
33 /* FUNCTION RELEASE */
34 /* */
35 /* _gx_display_driver_generic_filled_circle_draw PORTABLE C */
36 /* 6.1 */
37 /* AUTHOR */
38 /* */
39 /* Kenneth Maxwell, Microsoft Corporation */
40 /* */
41 /* DESCRIPTION */
42 /* */
43 /* Display driver to draw filled circals. */
44 /* */
45 /* INPUT */
46 /* */
47 /* context Drawing context */
48 /* xcenter x-coord of center of circle */
49 /* ycenter y-coord of center of circle */
50 /* r Radius of circle */
51 /* */
52 /* OUTPUT */
53 /* */
54 /* None */
55 /* */
56 /* CALLS */
57 /* */
58 /* [gx_display_driver_horizontal_line_draw] */
59 /* Driver-level horizontal line */
60 /* draw function */
61 /* */
62 /* CALLED BY */
63 /* */
64 /* _gx_display_driver_generic_simple_wide_line_draw */
65 /* */
66 /* RELEASE HISTORY */
67 /* */
68 /* DATE NAME DESCRIPTION */
69 /* */
70 /* 05-19-2020 Kenneth Maxwell Initial Version 6.0 */
71 /* 09-30-2020 Kenneth Maxwell Modified comment(s), */
72 /* resulting in version 6.1 */
73 /* */
74 /**************************************************************************/
_gx_display_driver_generic_filled_circle_draw(GX_DRAW_CONTEXT * context,GX_FIXED_VAL xcenter,GX_FIXED_VAL ycenter,GX_FIXED_VAL r)75 VOID _gx_display_driver_generic_filled_circle_draw(GX_DRAW_CONTEXT *context, GX_FIXED_VAL xcenter, GX_FIXED_VAL ycenter, GX_FIXED_VAL r)
76 {
77 /* The circle draw function is implemented from midpoint circle algorithm. */
78
79 GX_DISPLAY *display;
80 GX_RECTANGLE *clip;
81 GX_BRUSH *brush;
82 INT x;
83 INT y;
84 GX_BYTE ysign[2] = {1, -1};
85 INT index;
86 INT yi;
87 GX_VALUE xstart;
88 GX_VALUE xend;
89 GX_FIXED_VAL xfraction;
90 GX_FIXED_VAL yfraction;
91 INT decision;
92 INT half_shift;
93
94 display = context -> gx_draw_context_display;
95 clip = context -> gx_draw_context_clip;
96 brush = &context -> gx_draw_context_brush;
97
98 xfraction = (xcenter & GX_FIXED_VAL_FRACTION_MASK);
99 yfraction = (ycenter & GX_FIXED_VAL_FRACTION_MASK);
100
101 r -= GX_FIXED_VAL_HALF;
102
103 if (xfraction)
104 {
105 x = GX_FIXED_VAL_ONE - xfraction;
106 }
107 else
108 {
109 x = 0;
110 }
111 y = GX_FIXED_VAL_RND_UP(r + yfraction);
112 y = GX_FIXED_VAL_MAKE(y) - yfraction;
113
114 half_shift = GX_FIXED_VAL_SHIFT >> 1;
115
116 if ((x == 0) && (y == r))
117 {
118 decision = 256 - r;
119 }
120 else
121 {
122 decision = (x >> half_shift) * (x >> half_shift);
123 decision += ((y - GX_FIXED_VAL_HALF) >> half_shift) * ((y - GX_FIXED_VAL_HALF) >> half_shift);
124 decision -= ((r >> half_shift) * (r >> half_shift));
125 }
126
127 while (1)
128 {
129 if (decision < 0)
130 {
131 decision += 2 * x + GX_FIXED_VAL_ONE;
132 }
133 else
134 {
135 decision += 2 * (x - y) + GX_FIXED_VAL_MAKE(3);
136 y -= GX_FIXED_VAL_ONE;
137 }
138
139 if (x > y)
140 {
141 break;
142 }
143
144 for (index = 0; index < 2; index++)
145 {
146 xstart = (GX_VALUE)GX_FIXED_VAL_TO_INT(xcenter - x);
147 xend = (GX_VALUE)GX_FIXED_VAL_TO_INT(xcenter + x);
148 yi = (GX_VALUE)GX_FIXED_VAL_TO_INT(ycenter + y * ysign[index]);
149
150 if (xstart < clip -> gx_rectangle_left)
151 {
152 xstart = clip -> gx_rectangle_left;
153 }
154
155 if (xend > clip -> gx_rectangle_right)
156 {
157 xend = clip -> gx_rectangle_right;
158 }
159
160 if (xstart <= xend &&
161 yi >= clip -> gx_rectangle_top &&
162 yi <= clip -> gx_rectangle_bottom)
163 {
164 display -> gx_display_driver_horizontal_line_draw(context, xstart, xend, yi, 1, brush -> gx_brush_line_color);
165 }
166 }
167
168 x += GX_FIXED_VAL_ONE;
169 }
170
171 x = GX_FIXED_VAL_RND_UP(r + xfraction);
172 x = GX_FIXED_VAL_MAKE(x) - xfraction;
173
174 if (yfraction)
175 {
176 y = yfraction;
177 }
178 else
179 {
180 y = 0;
181 }
182
183 if ((y == 0) && (x == r))
184 {
185 decision = 256 - r;
186 }
187 else
188 {
189 decision = (((x - GX_FIXED_VAL_HALF) >> half_shift) * ((x - GX_FIXED_VAL_HALF) >> half_shift));
190 decision += ((y >> half_shift) * (y >> half_shift));
191 decision -= ((r >> half_shift) * (r >> half_shift));
192 }
193
194 while (1)
195 {
196 if (decision < 0)
197 {
198 decision += 2 * y + GX_FIXED_VAL_ONE;
199 }
200 else
201 {
202 decision += 2 * (y - x) + GX_FIXED_VAL_MAKE(3);
203 x -= GX_FIXED_VAL_ONE;
204 }
205
206 if (x <= y)
207 {
208 break;
209 }
210
211 for (index = 0; index < 2; index++)
212 {
213 xstart = (GX_VALUE)GX_FIXED_VAL_TO_INT(xcenter - x);
214 xend = (GX_VALUE)GX_FIXED_VAL_TO_INT(xcenter + x);
215 yi = (GX_VALUE)GX_FIXED_VAL_TO_INT(ycenter + y * ysign[index]);
216
217 if (xstart < clip -> gx_rectangle_left)
218 {
219 xstart = clip -> gx_rectangle_left;
220 }
221
222 if (xend > clip -> gx_rectangle_right)
223 {
224 xend = clip -> gx_rectangle_right;
225 }
226
227 if (xstart <= xend &&
228 yi >= clip -> gx_rectangle_top &&
229 yi <= clip -> gx_rectangle_bottom)
230 {
231 display -> gx_display_driver_horizontal_line_draw(context, xstart, xend, yi, 1, brush -> gx_brush_line_color);
232 }
233 }
234
235 y += GX_FIXED_VAL_ONE;
236 }
237 }
238
239
