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
|
# Sequence System Documentation
This document describes the `.seq` file format used to define demo timelines.
## Overview
Sequence files (`.seq`) define the timeline and layering of visual effects. They are compiled by `seq_compiler` into C++ code at build time.
**Locations:**
- Main demo: `workspaces/main/timeline.seq`
- Test demo: `workspaces/test/timeline.seq`
- Compiler: `tools/seq_compiler.cc`
- Generated output: `src/generated/timeline.cc`
---
## Syntax Reference
### BPM Declaration
```
# BPM 120
```
Specifies beats per minute. Required. Used to convert beats to physical seconds at runtime.
### END_DEMO Directive
```
END_DEMO <time>
```
Optional auto-exit time in beats (e.g., `64` or `64b`) or explicit seconds (`32.0s`).
### SEQUENCE Declaration
```
SEQUENCE <global_start> <priority> ["optional_name"] [optional_end]
EFFECT <+|=|-> <EffectClassName> <local_start> <local_end> [constructor_args...]
```
**Parameters:**
- `global_start`: Sequence start time in beats (default) or explicit seconds (`2.5s`)
- `priority`: Render order (0-9 for scenes, 10+ for post-processing)
- `"optional_name"`: Optional display name for Gantt charts
- `[optional_end]`: Optional sequence end time in beats (forces effect termination)
**Examples:**
```
SEQUENCE 0 0 # Basic sequence
SEQUENCE 0 0 "Intro" # Named sequence
SEQUENCE 0 0 [5.0] # Explicit end time
SEQUENCE 0 0 "Action Scene" [10.0] # Both name and end time
```
### EFFECT Declaration
```
EFFECT <+|=|-> <EffectClassName> <local_start> <local_end> [constructor_args...]
```
**Priority Modifiers:**
- `+`: Increment priority (or start at 0 if first)
- `=`: Keep same priority as previous
- `-`: Decrement priority (or start at -1 if first, for backgrounds)
**Parameters:**
- `EffectClassName`: C++ class from `demo_effects.h`
- `local_start`, `local_end`: Time in beats relative to sequence start
- `constructor_args`: Optional (rarely used, most effects use standard params only)
---
## Time Notation
**Beat-based timing (default):** All times are in musical beats, ensuring alignment regardless of BPM changes.
| Notation | Example | Description |
|----------|---------|-------------|
| **Beats (default)** | `0`, `4`, `16` | Integer or decimal, no suffix |
| Explicit beats | `4b`, `16.5b` | Optional 'b' suffix for clarity |
| Explicit seconds | `2.0s`, `8.25s` | Suffix 's' for physical time (rare) |
**Conversion:** At 120 BPM, 1 beat = 0.5 seconds, 4 beats = 2 seconds
**Why beats?**
- Musical alignment: Sequences stay synchronized to music structure
- BPM independence: Changing BPM preserves musical timing
- Intuitive authoring: Timeline matches bars/beats
---
## Runtime Parameters
All effects receive these parameters every frame in `render()` via `CommonPostProcessUniforms`:
| Parameter | Type | Description |
|-----------|------|-------------|
| `resolution` | vec2 | Screen dimensions in pixels |
| `aspect_ratio` | float | Screen width/height ratio |
| `time` | float | Physical time in seconds (unaffected by tempo) |
| `beat_time` | float | Musical time in beats (absolute) |
| `beat_phase` | float | Fractional beat (0.0-1.0 within current beat) |
| `audio_intensity` | float | Audio peak (0.0-1.0, for beat sync) |
**Use cases:**
- `time`: Physics-based animation (constant speed)
- `beat_time`: Musical animation (sync to bars/beats)
- `beat_phase`: Smooth oscillation per beat
---
## Priority System
**Scene Effects (0-9):**
- `-1`: Background (skybox, far objects)
- `0-5`: Midground (main geometry)
- `6-9`: Foreground (overlays, particles)
**Post-Process (10+):**
- Applied in order: blur → distortion → color grading
- Higher priority = rendered later (on top)
---
## Examples
### Basic Sequence
```
# BPM 120
SEQUENCE 0 0
EFFECT + FlashEffect 0 1 # Priority 0, beats 0-1 (0-0.5s @ 120 BPM)
EFFECT + HeptagonEffect 0.4 20 # Priority 1, beats 0.4-20
```
### Same Priority Layering
```
SEQUENCE 0 0
EFFECT + Flash 0 1 # Priority 0
EFFECT = Fade 0.2 0.6 # Priority 0 (same layer)
EFFECT + Other 0.4 6 # Priority 1
```
### Background Elements
```
SEQUENCE 0 0
EFFECT - FlashCube 0 20 # Priority -1 (background)
EFFECT = BgEffect 0 10 # Priority -1 (same layer)
EFFECT + MainEffect 0 20 # Priority 0 (foreground)
```
### Sequence with Explicit End
```
SEQUENCE 16 0 [10]
EFFECT + Particles 0 240 # Runs until beat 26 (sequence end at 16+10)
```
### Post-Processing Chain
```
SEQUENCE 0 10
EFFECT + GaussianBlur 0 120 # Applied first
EFFECT + ChromaAberration 0 120 # Applied second
EFFECT + Solarize 0 120 # Applied last
```
### Four-Bar Sequence (16 beats)
```
# BPM 120
SEQUENCE 0 0 "Intro"
EFFECT + Flash 0 1 # First beat
EFFECT + Heptagon 4 12 # Second bar through third bar
EFFECT + Fade 15 16 # Final beat
```
### Explicit Physical Time (Rare)
```
SEQUENCE 2.5s 0 "Intro timing" # Start at 2.5 physical seconds
EFFECT + Fade 0 4 # Fade from beat 0-4 (relative)
```
---
## Visualization
### Gantt Charts
**ASCII Chart (Terminal):**
```bash
./build/seq_compiler workspaces/main/timeline.seq --gantt=timeline.txt
```
**HTML/SVG Chart (Recommended):**
```bash
./build/seq_compiler workspaces/main/timeline.seq --gantt-html=timeline.html
```
Interactive visualization with hover tooltips, color coding, and zoom/pan.
### Validation Only
```bash
./build/seq_compiler workspaces/main/timeline.seq
```
Validates syntax without generating code.
---
## Integration
CMake automatically invokes the compiler on workspace timeline changes:
```cmake
add_custom_command(
OUTPUT ${GENERATED_DIR}/timeline.cc
COMMAND seq_compiler ${WORKSPACE_TIMELINE} ${GENERATED_DIR}/timeline.cc
DEPENDS ${WORKSPACE_TIMELINE}
)
```
---
## See Also
- `workspaces/main/timeline.seq` - Main demo timeline
- `workspaces/test/timeline.seq` - Test demo timeline
- `doc/WORKSPACE_SYSTEM.md` - Workspace organization
- `src/gpu/demo_effects.h` - Available effect classes
- `doc/HOWTO.md` - Building and running
|
