1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
#include <stdint.h>
#include <inttypes.h>
#include <math.h>
#include "fb.h"
#include "rototiller.h"
/* Copyright (C) 2016 Vito Caputo <vcaputo@pengaru.com> */
/* Some defines for the fixed-point stuff in render(). */
#define FIXED_TRIG_LUT_SIZE 4096 /* size of the cos/sin look-up tables */
#define FIXED_BITS 11 /* fractional bits */
#define FIXED_EXP (1 << FIXED_BITS) /* 2^FIXED_BITS */
#define FIXED_MASK (FIXED_EXP - 1) /* fractional part mask */
#define FIXED_COS(_rad) costab[(_rad) % FIXED_TRIG_LUT_SIZE]
#define FIXED_SIN(_rad) sintab[(_rad) % FIXED_TRIG_LUT_SIZE]
#define FIXED_MULT(_a, _b) (((_a) * (_b)) >> FIXED_BITS)
#define FIXED_NEW(_i) ((_i) << FIXED_BITS)
#define FIXED_TO_INT(_f) ((_f) >> FIXED_BITS)
/* Draw a rotating checkered 256x256 texture into fragment. (32-bit version) */
static void roto32(fb_fragment_t *fragment)
{
static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE];
static uint8_t texture[256][256];
static int initialized;
static uint32_t colors[2];
static unsigned r, rr;
int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r;
int x, y, stride = fragment->stride / 4, width = fragment->width, height = fragment->height;
uint8_t tx, ty; /* 256x256 texture; 8 bit texture indices to modulo via overflow. */
uint32_t *buf = fragment->buf;
if (!initialized) {
int i;
initialized = 1;
/* Generate simple checker pattern texture, nothing clever, feel free to play! */
/* If you modify texture on every frame instead of only @ initialization you can
* produce some neat output. These values are indexed into colors[] below. */
for (y = 0; y < 128; y++) {
for (x = 0; x < 128; x++)
texture[y][x] = 1;
for (; x < 256; x++)
texture[y][x] = 0;
}
for (; y < 256; y++) {
for (x = 0; x < 128; x++)
texture[y][x] = 0;
for (; x < 256; x++)
texture[y][x] = 1;
}
/* Generate fixed-point cos & sin LUTs. */
for (i = 0; i < FIXED_TRIG_LUT_SIZE; i++) {
costab[i] = ((cos((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
sintab[i] = ((sin((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
}
}
/* This is all done using fixed-point in the hopes of being faster, and yes assumptions
* are being made WRT the overflow of tx/ty as well, only tested on x86_64. */
cos_r = FIXED_COS(r);
sin_r = FIXED_SIN(r);
/* Vary the colors, this is just a mashup of sinusoidal rgb values. */
colors[0] = ((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127))) + 128) << 16) |
((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127))) + 128) << 8) |
((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127))) + 128));
colors[1] = ((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127))) + 128) << 16) |
((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127))) + 128)) << 8 |
((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127))) + 128) );
/* The dimensions are cut in half and negated to center the rotation. */
/* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */
x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r);
x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r);
y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r);
y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r);
for (y = 0; y < height; y++) {
x_cos_r = x_cos_r_init;
x_sin_r = x_sin_r_init;
for (x = 0; x < width; x++, buf++) {
tx = FIXED_TO_INT(x_sin_r - y_cos_r);
ty = FIXED_TO_INT(y_sin_r + x_cos_r);
*buf = colors[texture[ty][tx]];
x_cos_r += cos_r;
x_sin_r += sin_r;
}
buf += stride;
y_cos_r += cos_r;
y_sin_r += sin_r;
}
// This governs the rotation and color cycle.
r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16)));
rr += 2;
}
/* Draw a rotating checkered 256x256 texture into fragment. (64-bit version) */
static void roto64(fb_fragment_t *fragment)
{
static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE];
static uint8_t texture[256][256];
static int initialized;
static uint32_t colors[2];
static unsigned r, rr;
int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r;
int x, y, stride = fragment->stride / 8, width = fragment->width, height = fragment->height;
uint8_t tx, ty; /* 256x256 texture; 8 bit texture indices to modulo via overflow. */
uint64_t *buf = (uint64_t *)fragment->buf;
if (!initialized) {
int i;
initialized = 1;
/* Generate simple checker pattern texture, nothing clever, feel free to play! */
/* If you modify texture on every frame instead of only @ initialization you can
* produce some neat output. These values are indexed into colors[] below. */
for (y = 0; y < 128; y++) {
for (x = 0; x < 128; x++)
texture[y][x] = 1;
for (; x < 256; x++)
texture[y][x] = 0;
}
for (; y < 256; y++) {
for (x = 0; x < 128; x++)
texture[y][x] = 0;
for (; x < 256; x++)
texture[y][x] = 1;
}
/* Generate fixed-point cos & sin LUTs. */
for (i = 0; i < FIXED_TRIG_LUT_SIZE; i++) {
costab[i] = ((cos((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
sintab[i] = ((sin((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
}
}
/* This is all done using fixed-point in the hopes of being faster, and yes assumptions
* are being made WRT the overflow of tx/ty as well, only tested on x86_64. */
cos_r = FIXED_COS(r);
sin_r = FIXED_SIN(r);
/* Vary the colors, this is just a mashup of sinusoidal rgb values. */
colors[0] = ((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127))) + 128) << 16) |
((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127))) + 128) << 8) |
((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127))) + 128));
colors[1] = ((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127))) + 128) << 16) |
((FIXED_TO_INT(FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127))) + 128)) << 8 |
((FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127))) + 128) );
/* The dimensions are cut in half and negated to center the rotation. */
/* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */
x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r);
x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r);
y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r);
y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r);
width /= 2; /* Since we're processing 64-bit words (2 pixels) at a time */
for (y = 0; y < height; y++) {
x_cos_r = x_cos_r_init;
x_sin_r = x_sin_r_init;
for (x = 0; x < width; x++, buf++) {
uint64_t p;
tx = FIXED_TO_INT(x_sin_r - y_cos_r);
ty = FIXED_TO_INT(y_sin_r + x_cos_r);
p = colors[texture[ty][tx]];
x_cos_r += cos_r;
x_sin_r += sin_r;
tx = FIXED_TO_INT(x_sin_r - y_cos_r);
ty = FIXED_TO_INT(y_sin_r + x_cos_r);
p |= (uint64_t)colors[texture[ty][tx]] << 32;
*buf = p;
x_cos_r += cos_r;
x_sin_r += sin_r;
}
buf += stride;
y_cos_r += cos_r;
y_sin_r += sin_r;
}
// This governs the rotation and color cycle.
r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16)));
rr += 2;
}
rototiller_renderer_t roto32_renderer = {
.render = roto32,
.name = "roto32",
.description = "Tiled texture rotation (32-bit)",
.author = "Vito Caputo <vcaputo@pengaru.com>",
.license = "GPLv2",
};
rototiller_renderer_t roto64_renderer = {
.render = roto64,
.name = "roto64",
.description = "Tiled texture rotation (64-bit)",
.author = "Vito Caputo <vcaputo@pengaru.com>",
.license = "GPLv2",
};
|
