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
|
#include "ppu.h"
/*
Copyright (c) 2021 Devine Lu Linvega
Copyright (c) 2021 Andrew Alderwick
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE.
*/
static Uint8 font[][8] = {
{0x00, 0x7c, 0x82, 0x82, 0x82, 0x82, 0x82, 0x7c},
{0x00, 0x30, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10},
{0x00, 0x7c, 0x82, 0x02, 0x7c, 0x80, 0x80, 0xfe},
{0x00, 0x7c, 0x82, 0x02, 0x1c, 0x02, 0x82, 0x7c},
{0x00, 0x0c, 0x14, 0x24, 0x44, 0x84, 0xfe, 0x04},
{0x00, 0xfe, 0x80, 0x80, 0x7c, 0x02, 0x82, 0x7c},
{0x00, 0x7c, 0x82, 0x80, 0xfc, 0x82, 0x82, 0x7c},
{0x00, 0x7c, 0x82, 0x02, 0x1e, 0x02, 0x02, 0x02},
{0x00, 0x7c, 0x82, 0x82, 0x7c, 0x82, 0x82, 0x7c},
{0x00, 0x7c, 0x82, 0x82, 0x7e, 0x02, 0x82, 0x7c},
{0x00, 0x7c, 0x82, 0x02, 0x7e, 0x82, 0x82, 0x7e},
{0x00, 0xfc, 0x82, 0x82, 0xfc, 0x82, 0x82, 0xfc},
{0x00, 0x7c, 0x82, 0x80, 0x80, 0x80, 0x82, 0x7c},
{0x00, 0xfc, 0x82, 0x82, 0x82, 0x82, 0x82, 0xfc},
{0x00, 0x7c, 0x82, 0x80, 0xf0, 0x80, 0x82, 0x7c},
{0x00, 0x7c, 0x82, 0x80, 0xf0, 0x80, 0x80, 0x80}};
Uint8
readpixel(Uint8 *sprite, Uint8 h, Uint8 v)
{
Uint8 ch1 = ((sprite[v] >> h) & 0x1);
Uint8 ch2 = (((sprite[v + 8] >> h) & 0x1) << 1);
return ch1 + ch2;
}
void
clear(Ppu *p)
{
int i, sz = p->height * p->width, rows = sz / 4;
for(i = 0; i < sz; ++i)
p->output[i] = p->colors[0];
for(i = 0; i < rows; i++) {
p->fg[i] = 0;
p->bg[i] = 0;
}
}
void
putcolors(Ppu *p, Uint8 *addr)
{
int i;
for(i = 0; i < 4; ++i) {
Uint8
r = (*(addr + i / 2) >> (!(i % 2) << 2)) & 0x0f,
g = (*(addr + 2 + i / 2) >> (!(i % 2) << 2)) & 0x0f,
b = (*(addr + 4 + i / 2) >> (!(i % 2) << 2)) & 0x0f;
p->colors[i] = rgb15(r,g,b);
}
// p->colors[0] = COLOR_BLUE;
// p->colors[1] = COLOR_WHITE;
// p->colors[2] = COLOR_RED;
// p->colors[3] = COLOR_CYAN;
}
void
putpixel(Ppu *p, Uint8 *layer, Uint16 x, Uint16 y, Uint8 color)
{
Uint16 row = (y % 8) + ((x / 8 + y / 8 * p->hor) * 16), col = 7 - (x % 8);
if(x >= p->hor * 8 || y >= p->ver * 8 || row > (p->hor * p->ver * 16) - 8)
return;
if(color == 0 || color == 2)
layer[row] &= ~(1UL << col);
else
layer[row] |= 1UL << col;
if(color == 0 || color == 1)
layer[row + 8] &= ~(1UL << col);
else
layer[row + 8] |= 1UL << col;
}
void
puticn(Ppu *p, Uint8 *layer, Uint16 x, Uint16 y, Uint8 *sprite, Uint8 color, Uint8 flipx, Uint8 flipy)
{
Uint16 v, h;
for(v = 0; v < 8; v++)
for(h = 0; h < 8; h++) {
Uint8 ch1 = ((sprite[v] >> (7 - h)) & 0x1);
if(ch1 == 1 || (color != 0x05 && color != 0x0a && color != 0x0f))
putpixel(p,
layer,
x + (flipx ? 7 - h : h),
y + (flipy ? 7 - v : v),
ch1 ? color % 4 : color / 4);
}
}
void
putchr(Ppu *p, Uint8 *layer, Uint16 x, Uint16 y, Uint8 *sprite, Uint8 color, Uint8 flipx, Uint8 flipy)
{
Uint16 v, h;
for(v = 0; v < 8; v++)
for(h = 0; h < 8; h++) {
Uint8 ch1 = ((sprite[v] >> (7 - h)) & 0x1) * color;
Uint8 ch2 = ((sprite[v + 8] >> (7 - h)) & 0x1) * color;
putpixel(p,
layer,
x + (flipx ? 7 - h : h),
y + (flipy ? 7 - v : v),
(((ch1 + ch2 * 2) + color / 4) & 0x3));
}
}
/* output */
void
drawpixel(Ppu *p, Uint16 x, Uint16 y, Uint8 color)
{
if(x >= p->pad && x <= p->width - p->pad - 1 && y >= p->pad && y <= p->height - p->pad - 1)
p->output[y * p->width + x] = p->colors[color];
}
void
drawdebugger(Ppu *p, Uint8 *stack, Uint8 ptr)
{
Uint8 i, x, y, b;
for(i = 0; i < 0x20; ++i) { /* memory */
x = ((i % 8) * 3 + 1) * 8, y = (i / 8 + 1) * 8, b = stack[i];
puticn(p, p->bg, x, y, font[(b >> 4) & 0xf], 1 + (ptr == i) * 0x7, 0, 0);
puticn(p, p->bg, x + 8, y, font[b & 0xf], 1 + (ptr == i) * 0x7, 0, 0);
}
for(x = 0; x < 0x20; ++x) {
drawpixel(p, x, p->height / 2, 2);
drawpixel(p, p->width - x, p->height / 2, 2);
drawpixel(p, p->width / 2, p->height - x, 2);
drawpixel(p, p->width / 2, x, 2);
drawpixel(p, p->width / 2 - 16 + x, p->height / 2, 2);
drawpixel(p, p->width / 2, p->height / 2 - 16 + x, 2);
}
}
void
drawppu(Ppu *p)
{
Uint16 x, y;
for(y = 0; y < p->ver; ++y)
for(x = 0; x < p->hor; ++x) {
Uint8 v, h;
Uint16 key = (y * p->hor + x) * 16;
for(v = 0; v < 8; v++)
for(h = 0; h < 8; h++) {
Uint8 color = readpixel(&p->fg[key], h, v);
if(color == 0)
color = readpixel(&p->bg[key], h, v);
drawpixel(p, x * 8 + p->pad + 7 - h, y * 8 + p->pad + v, color);
}
}
}
int
initppu(Ppu *p, Uint8 hor, Uint8 ver, Uint8 pad)
{
p->hor = hor;
p->ver = ver;
p->pad = pad;
p->width = (8 * p->hor + p->pad * 2);
p->height = (8 * p->ver + p->pad * 2);
if(!(p->output = malloc(p->width * p->height * sizeof(Uint16))))
return 0;
if(!(p->bg = malloc(p->width * p->height * sizeof(Uint8) / 4)))
return 0;
if(!(p->fg = malloc(p->width * p->height * sizeof(Uint8) / 4)))
return 0;
clear(p);
return 1;
}
|
