fix(headless): add early returns to all effect constructors

All effects now skip GPU resource creation when device is nullptr.

Effects fixed:
- GaussianBlurEffect
- HeptagonEffect
- Hybrid3DEffect
- PassthroughEffect
- ParticlesEffect

Headless tests now passing (audio-only mode functional).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

5 files changed, 25 insertions, 0 deletions

diff --git a/src/effects/gaussian_blur_effect.cc b/src/effects/gaussian_blur_effect.cc
index 17c657f..fdf1807 100644
--- a/src/effects/gaussian_blur_effect.cc
+++ b/src/effects/gaussian_blur_effect.cc
@@ -9,6 +9,11 @@ GaussianBlurEffect::GaussianBlurEffect(const GpuContext& ctx,
                                            const std::vector<std::string>& outputs)
     : Effect(ctx, inputs, outputs), pipeline_(nullptr), bind_group_(nullptr),
       sampler_(nullptr) {
+  // Headless mode: skip GPU resource creation
+  if (ctx_.device == nullptr) {
+    return;
+  }
+
   // Create pipeline
   pipeline_ = create_post_process_pipeline(ctx_.device, WGPUTextureFormat_RGBA8Unorm,
                                            gaussian_blur_v2_shader_wgsl);
diff --git a/src/effects/heptagon_effect.cc b/src/effects/heptagon_effect.cc
index 27d59da..3321517 100644
--- a/src/effects/heptagon_effect.cc
+++ b/src/effects/heptagon_effect.cc
@@ -9,6 +9,11 @@ HeptagonEffect::HeptagonEffect(const GpuContext& ctx,
                                    const std::vector<std::string>& inputs,
                                    const std::vector<std::string>& outputs)
     : Effect(ctx, inputs, outputs), pipeline_(nullptr), bind_group_(nullptr), sampler_(nullptr) {
+  // Headless mode: skip GPU resource creation
+  if (ctx_.device == nullptr) {
+    return;
+  }
+
   // Init uniforms
   uniforms_buffer_.init(ctx_.device);
 
diff --git a/src/effects/hybrid3_d_effect.cc b/src/effects/hybrid3_d_effect.cc
index ced5b42..2a015a0 100644
--- a/src/effects/hybrid3_d_effect.cc
+++ b/src/effects/hybrid3_d_effect.cc
@@ -10,6 +10,11 @@ Hybrid3DEffect::Hybrid3DEffect(const GpuContext& ctx,
                                    const std::vector<std::string>& outputs)
     : Effect(ctx, inputs, outputs), depth_node_(outputs[0] + "_depth"),
       dummy_texture_(nullptr), dummy_texture_view_(nullptr) {
+  // Headless mode: skip GPU resource creation
+  if (ctx_.device == nullptr) {
+    return;
+  }
+
   // Initialize renderer (format is always RGBA8Unorm for v2)
   renderer_.init(ctx_.device, ctx_.queue, WGPUTextureFormat_RGBA8Unorm);
 
diff --git a/src/effects/particles_effect.cc b/src/effects/particles_effect.cc
index 9d73bf7..709acbf 100644
--- a/src/effects/particles_effect.cc
+++ b/src/effects/particles_effect.cc
@@ -10,6 +10,11 @@ ParticlesEffect::ParticlesEffect(const GpuContext& ctx,
                                      const std::vector<std::string>& inputs,
                                      const std::vector<std::string>& outputs)
     : Effect(ctx, inputs, outputs) {
+  // Headless mode: skip GPU resource creation
+  if (ctx_.device == nullptr) {
+    return;
+  }
+
   // Initialize uniforms
   uniforms_.init(ctx_.device);
 
diff --git a/src/effects/passthrough_effect.cc b/src/effects/passthrough_effect.cc
index ba98657..c4106b1 100644
--- a/src/effects/passthrough_effect.cc
+++ b/src/effects/passthrough_effect.cc
@@ -9,6 +9,11 @@ PassthroughEffect::PassthroughEffect(const GpuContext& ctx,
                                          const std::vector<std::string>& outputs)
     : Effect(ctx, inputs, outputs), pipeline_(nullptr), bind_group_(nullptr),
       sampler_(nullptr) {
+  // Headless mode: skip GPU resource creation
+  if (ctx_.device == nullptr) {
+    return;
+  }
+
   // Init uniform buffer
   uniforms_buffer_.init(ctx_.device);
   // Create pipeline (simple version without effect params)