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
|
vars /allvars
U[64] buf // A buffer that can store the current and next row
U curr_gen = 0 // Swap these offsets back and forth per generation
U next_gen = 32
UU drawing_row_offset = 0 // Use this to track which row we're drawing
U current_rule = 73
fn init_eca_state()
// Scroll to attributes
ppu_reset_addr($2000 + 960)
// Set attributes for background
for U i = 0; i < 64; i+= 1
{PPUDATA}(%11111111)
// Init the buffer to zero
buf = U[64]()
// Add an initial cell
buf[16] = 1
fn assemble_code(U left, U middle, U right) U
U out = %00000000
out |= left << 2
out |= middle << 1
out |= right
return out
fn calc_next_cell(U left, U middle, U right) U
U code = assemble_code(left, middle, right)
ct U mask7 = %10000000
ct U mask6 = %01000000
ct U mask5 = %00100000
ct U mask4 = %00010000
ct U mask3 = %00001000
ct U mask2 = %00000100
ct U mask1 = %00000010
ct U mask0 = %00000001
switch code
case %00000111
return (current_rule & mask7) >> 7
case %00000110
return (current_rule & mask6) >> 6
case %00000101
return (current_rule & mask5) >> 5
case %00000100
return (current_rule & mask4) >> 4
case %00000011
return (current_rule & mask3) >> 3
case %00000010
return (current_rule & mask2) >> 2
case %00000001
return (current_rule & mask1) >> 1
case %00000000
return (current_rule & mask0) >> 0
fn calc_and_advance_gen()
// Calculate the next row's values
U left_ind = 0
U right_ind = 0
U left_cell = 0
U mid_cell = 0
U right_cell = 0
U next_cell = 0
for U i = 0; i < 32; i += 1
// Calculate indices for left and right of cell
if i == 0
left_ind = 31
else
left_ind = i - 1
if i == 31
right_ind = 0
else
right_ind = i + 1
// Get left and right of cell
left_cell = buf[curr_gen + left_ind]
mid_cell = buf[curr_gen + i]
right_cell = buf[curr_gen + right_ind]
// Calc next cell
next_cell = calc_next_cell(left_cell, mid_cell, right_cell)
// Set next cell
buf[next_gen + i] = next_cell
// Advance next generation
if curr_gen == 0
curr_gen = 32
next_gen = 0
else
curr_gen = 0
next_gen = 32
// advance drawing row offset, looping back to top
drawing_row_offset += 1
if drawing_row_offset == 30
drawing_row_offset = 0
fn upload_curr_gen()
// "scroll" to the row we're at
UU row_start = $2000
row_start += (drawing_row_offset * 32)
ppu_reset_addr(row_start)
for U i = 0; i < 32; i += 1 //32 columns
//next_cell = 0 //get_next_gen(i)
{PPUDATA}(buf[i+curr_gen])
nmi eca_nmi()
// Turn on rendering sprites and bg
{PPUMASK}(PPUMASK_ON | PPUMASK_NO_CLIP)
upload_curr_gen()
ppu_reset_scroll(0, 0)
// Main mode for running the ECA
mode eca_main()
: nmi eca_nmi
// Initialize the screen
init_eca_state()
// Wait 10 frames
nmi
nmi
nmi
nmi
nmi
nmi
nmi
nmi
nmi
nmi
// Loop forever:
while true
nmi
calc_and_advance_gen()
charmap(".#-=n!@~E$%^S&*(C)_+A{}|12345678qwertyuiop<asd>")
data /titlescreen
[] title
("................................"
"................................"
"................................"
"................................"
"..........############.........."
".........##############........."
".........##..........##........."
".........##..........##........."
".........##..n!E$S&..##........."
".........##..@~%^*(..##........."
".........##....C)....##........."
".........##...._+....##........."
".........##....A{....##........."
".........##....}|....##........."
".........##..........##........."
".........##..........##........."
".........##############........."
"..........############.........."
"................................"
"................................"
"...........###########.........."
"..........#..........#.........."
"..........#.12345678.#.........."
"..........#...<...>..#.........."
"..........#..........#.........."
"..........###########..........."
"................................"
"................................"
"................................"
"................................"
"................................")
vars /titlescreen
UU wipeline = 0
// nmi for entrypoint for the program
nmi main_nmi()
// Turn on rendering sprites and bg
{PPUMASK}(PPUMASK_ON | PPUMASK_NO_CLIP)
ppu_reset_scroll(0, 0)
if wipeline
UU row_start = $2000
row_start += ((wipeline - 1) * 32)
ppu_reset_addr(row_start)
for U i = 0; i < 32; i += 1 //32 columns
//next_cell = 0 //get_next_gen(i)
{PPUDATA}(0)
// The main entry point for the program
mode main()
: nmi main_nmi
// Set the palette:
palette = example_palette
ppu_upload_palette()
ppu_reset_addr($2000)
// Load the title screen
CCC/titlescreen titlep = @title
for UU i = 0; i < 960; i += 1
{PPUDATA}(titlep{i})
for UU i = 0; i < 64; i += 1
{PPUDATA}(%00000000)
// Turn rendering on
{PPUMASK}(PPUMASK_BG_ON)
// Turn the NMI on
{PPUCTRL}(PPUCTRL_NMI_ON)
// Display title screen for 120 frames
for U i = 0; i < 120; i += 1
nmi
for U i = 1; i <= 30; i += 1 // use this to wipe the screen
wipeline = i
nmi
// Go to the main eca mode
goto mode eca_main()
: preserves /allvars
// Define the tileset (commonly called CHR):
chrrom
file(fmt, "spritesheet.chr")
|
