add-effect

name: add-effect description: Use when adding a new transform effect, creating a post-process shader, or planning effect implementation. Provides the complete checklist of files and commonly-missed steps.

Adding a Transform Effect

Follow this checklist when adding a new transform effect to AudioJones. Effects use a self-registering modular structure — config, runtime state, lifecycle functions, and registration all live together in src/effects/.

Checklist Overview

Transform effects require changes across 5 files. The REGISTER_EFFECT macro at the bottom of the .cpp file handles lifecycle registration, descriptor metadata, UI dispatch, and pipeline integration — no central lists to edit. Per-effect runtime state lives in a file-local static <Name>Effect g_<field>State declared by the macro and accessed through pe->effectStates[TRANSFORM_<NAME>]; no PostEffect changes are needed.

Steps commonly missed:

1. TransformOrderConfig::order array - Effect won't appear in reorder UI
2. REGISTER_EFFECT macro at bottom of .cpp - Effect won't init, won't appear in pipeline
3. Get<Name>Effect() accessor and non-static Setup<Name>() bridge - Macro can't link the setup binding

Phase 1: Effect Module

Create src/effects/{effect_name}.h:

#ifndef {EFFECT_NAME}_EFFECT_H
#define {EFFECT_NAME}_EFFECT_H

#include "raylib.h"
#include <stdbool.h>

// Brief description of what the effect does
struct {EffectName}Config {
  bool enabled = false;
  // Add effect-specific parameters with defaults
  float speed = 1.0f;  // Animation rate (radians/second)
};



#define {EFFECT_NAME}_CONFIG_FIELDS enabled, speed

typedef struct {EffectName}Effect {
  Shader shader;
  int {param}Loc;      // One int per uniform
  float time;          // Animation accumulator (if animated)
} {EffectName}Effect;

bool {EffectName}EffectInit({EffectName}Effect* e);
void {EffectName}EffectSetup({EffectName}Effect* e, const {EffectName}Config* cfg, float deltaTime);
void {EffectName}EffectUninit({EffectName}Effect* e);
void {EffectName}RegisterParams({EffectName}Config *cfg);
#endif

Create src/effects/{effect_name}.cpp:

#include "{effect_name}.h"
#include "automation/mod_sources.h"
#include "automation/modulation_engine.h"
#include "config/constants.h"
#include "config/effect_descriptor.h"
#include "render/post_effect.h"

#include "imgui.h"
#include "ui/modulatable_slider.h"

#include <stddef.h>

bool {EffectName}EffectInit({EffectName}Effect* e) {
  e->shader = LoadShader(NULL, "shaders/{effect_name}.fs");
  if (e->shader.id == 0) return false;

  e->{param}Loc = GetShaderLocation(e->shader, "{param}");
  e->time = 0.0f;
  return true;
}

void {EffectName}EffectSetup({EffectName}Effect* e, const {EffectName}Config* cfg, float deltaTime) {
  e->time += cfg->speed * deltaTime;
  SetShaderValue(e->shader, e->{param}Loc, &cfg->{param}, SHADER_UNIFORM_FLOAT);
}

void {EffectName}EffectUninit({EffectName}Effect* e) {
  UnloadShader(e->shader);
}

void {EffectName}RegisterParams({EffectName}Config *cfg) {
  ModEngineRegisterParam("{effectName}.{param}", &cfg->{param}, {min}f, {max}f);
}

{EffectName}Effect *Get{EffectName}Effect(PostEffect *pe) {
  return ({EffectName}Effect *)pe->effectStates[TRANSFORM_{EFFECT_NAME}];
}

void Setup{EffectName}(PostEffect *pe) {
  {EffectName}EffectSetup(Get{EffectName}Effect(pe), &pe->effects.{effectName},
                          pe->currentDeltaTime);
}

// === UI ===

static void Draw{EffectName}Params(EffectConfig *e, const ModSources *ms,
                                   ImU32 glow) {
  (void)glow;
  {EffectName}Config *cfg = &e->{effectName};

  ModulatableSlider("Param##{effectName}", &cfg->{param},
                    "{effectName}.{param}", "%.2f", ms);
}

// clang-format off
REGISTER_EFFECT(TRANSFORM_{EFFECT_NAME}, {EffectName}, {effectName},
                "Effect Name", "{CAT}", {sectionIndex}, EFFECT_FLAG_NONE,
                Setup{EffectName}, NULL, Draw{EffectName}Params)
// clang-format on

The REGISTER_EFFECT macro at the bottom handles:

• Descriptor metadata (display name, category badge, section index, flags, enabledOffset)
• Lifecycle registration (init, uninit, registerParams, getShader)
• Setup function dispatch binding
• UI draw callback (the dispatch system calls drawParams per effect)

The // === UI === section contains the colocated Draw{EffectName}Params() function with signature (EffectConfig*, const ModSources*, ImU32). The dispatch system in imgui_effects_dispatch.cpp handles section begin/end, enable checkbox, and transform reordering — the draw function only renders effect-specific sliders.

The setup function (Setup{EffectName}) is non-static (referenced by name in the registration macro) and lives just above the // === UI === divider, alongside the non-static Get{EffectName}Effect() accessor. The accessor casts pe->effectStates[TRANSFORM_{EFFECT_NAME}] to the effect's type; the bridge calls the module's {EffectName}EffectSetup() with that pointer plus &pe->effects.{effectName}. The Draw{EffectName}Params UI callback is static.

Use snake_case for filename, PascalCase for struct/function names.

Macro Variants

Pick the right macro based on the Init signature:

For multi-pass effects with composite shaders (like bloom, anamorphic streak), write a manual EffectDescriptorRegister() call with custom GetShader/Resize wrappers instead of using a macro.

Macro Parameters

REGISTER_EFFECT(Type, Name, field, displayName, badge, section, flags, SetupFn, ResizeFn, DrawParamsFnArg)

• Type: TransformEffectType enum value (e.g., TRANSFORM_SINE_WARP)
• Name: PascalCase prefix for functions (e.g., SineWarp)
• field: camelCase field name on PostEffect and EffectConfig (e.g., sineWarp)
• displayName: UI display string (e.g., "Sine Warp")
• badge: Category badge
• section: Category section index
• flags: EFFECT_FLAG_NONE, EFFECT_FLAG_HALF_RES, EFFECT_FLAG_NEEDS_RESIZE
• SetupFn: Setup function name (e.g., SetupSineWarp) — defined as static above the macro in the same .cpp
• ResizeFn: Resize function or NULL
• DrawParamsFnArg: Colocated UI draw function (e.g., DrawSineWarpParams) — signature: void (*)(EffectConfig*, const ModSources*, ImU32)

REGISTER_GENERATOR(Type, Name, field, displayName, SetupFn, ScratchSetupFn, section, DrawParamsFnArg, DrawOutputFnArg)

• SetupFn: Blend compositor setup function
• ScratchSetupFn: Generator shader setup function
• section: Generator sub-category section index (10=Geometric, 11=Filament, 12=Texture, 13=Atmosphere)
• DrawParamsFnArg: Effect-specific UI sliders function
• DrawOutputFnArg: Output section function (typically DrawOutput_{field} generated by STANDARD_GENERATOR_OUTPUT)

Category badges: "SYM" (0), "WARP" (1), "CELL" (2), "MOT" (3), "ART" (4), "GFX" (5), "RET" (6), "OPT" (7), "COL" (8), "SIM" (9), "GEN" (10=Geometric, 11=Filament, 12=Texture, 13=Atmosphere).

Phase 2: Config Registration

Modify src/config/effect_config.h:

1. Add include at top with other effect headers:

   #include "effects/{effect_name}.h"
   

2. Add enum entry in TransformEffectType before TRANSFORM_EFFECT_COUNT:

   TRANSFORM_{EFFECT_NAME},
   

3. Add to order array in TransformOrderConfig::order initialization:

   TRANSFORM_{EFFECT_NAME}
   

   Place at end of array, before closing brace. COMMONLY MISSED.

4. Add config member to EffectConfig struct:

   {EffectName}Config {effectName};
   

Phase 3: Shader

Create shaders/{effect_name}.fs.

Attribution (REQUIRED if derived from external source): If the research doc has an ## Attribution section, the shader file MUST begin with an attribution comment block before the #version line:

// Based on "Shader Title" by AuthorName
// https://www.shadertoy.com/view/XXXX
// License: CC BY-NC-SA 3.0 Unported
// Modified: [brief description of changes for AudioJones]

#version 330

in vec2 fragTexCoord;
out vec4 finalColor;

uniform sampler2D texture0;
uniform vec2 resolution;
// Add effect-specific uniforms

void main() {
    vec2 uv = fragTexCoord;
    vec4 color = texture(texture0, uv);

    // Effect algorithm here

    finalColor = color;
}

Phase 4: Preset Serialization

Modify src/config/effect_serialization.cpp:

1. Add include for the effect header (so the *_CONFIG_FIELDS macro is visible):

   #include "effects/{effect_name}.h"
   

2. Add JSON macro with the other per-config macros, referencing the header's field-list macro:

   NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT({EffectName}Config, {EFFECT_NAME}_CONFIG_FIELDS)
   

3. Add field name to the EFFECT_CONFIG_FIELDS(X) X-macro table:

   X({effectName}) \
   

   This single entry handles both to_json (writes if enabled) and from_json (reads with default).

Verification

After implementation, verify:

• Effect appears in transform order pipeline
• Effect shows correct category badge (not "???")
• Effect can be reordered via drag-drop
• Enabling effect adds it to the pipeline list
• UI controls modify effect in real-time
• Preset save/load preserves settings
• Modulation routes to registered parameters (if applicable)
• Build succeeds with no warnings

File Summary