diff options
Diffstat (limited to 'src/audio/spectral_brush.h')
| -rw-r--r-- | src/audio/spectral_brush.h | 56 |
1 files changed, 23 insertions, 33 deletions
diff --git a/src/audio/spectral_brush.h b/src/audio/spectral_brush.h index 3125f35..be27bbb 100644 --- a/src/audio/spectral_brush.h +++ b/src/audio/spectral_brush.h @@ -1,6 +1,7 @@ // This file is part of the 64k demo project. // It implements the "Spectral Brush" primitive for procedural audio generation. -// Spectral brushes trace Bezier curves through spectrograms with vertical profiles. +// Spectral brushes trace Bezier curves through spectrograms with vertical +// profiles. #pragma once @@ -8,9 +9,9 @@ // Profile types for vertical distribution around central Bezier curve enum ProfileType { - PROFILE_GAUSSIAN = 0, // Smooth harmonic falloff - PROFILE_DECAYING_SINUSOID = 1, // Resonant/metallic texture - PROFILE_NOISE = 2 // Random texture/grit + PROFILE_GAUSSIAN = 0, // Smooth harmonic falloff + PROFILE_DECAYING_SINUSOID = 1, // Resonant/metallic texture + PROFILE_NOISE = 2 // Random texture/grit }; // Evaluate linear Bezier interpolation at given frame @@ -18,11 +19,11 @@ enum ProfileType { // control_values: Array of values at control points (freq_hz or amplitude) // n_points: Number of control points // frame: Frame number to evaluate at -// Returns: Interpolated value at frame (linearly interpolated between control points) +// Returns: Interpolated value at frame (linearly interpolated between control +// points) float evaluate_bezier_linear(const float* control_frames, - const float* control_values, - int n_points, - float frame); + const float* control_values, int n_points, + float frame); // Draw a spectral brush stroke onto a spectrogram // Traces a Bezier curve through time-frequency space with a vertical profile @@ -34,32 +35,24 @@ float evaluate_bezier_linear(const float* control_frames, // control_amps: Amplitude values at control points (0.0-1.0 typical) // n_control_points: Number of control points (minimum 2 for a curve) // profile_type: Type of vertical profile to apply -// profile_param1: First parameter (sigma for Gaussian, decay for sinusoid, amplitude for noise) -// profile_param2: Second parameter (unused for Gaussian, frequency for sinusoid, seed for noise) -void draw_bezier_curve(float* spectrogram, - int dct_size, - int num_frames, +// profile_param1: First parameter (sigma for Gaussian, decay for sinusoid, +// amplitude for noise) profile_param2: Second parameter (unused for Gaussian, +// frequency for sinusoid, seed for noise) +void draw_bezier_curve(float* spectrogram, int dct_size, int num_frames, const float* control_frames, - const float* control_freqs_hz, - const float* control_amps, - int n_control_points, - ProfileType profile_type, - float profile_param1, - float profile_param2 = 0.0f); + const float* control_freqs_hz, const float* control_amps, + int n_control_points, ProfileType profile_type, + float profile_param1, float profile_param2 = 0.0f); // Additive variant of draw_bezier_curve (adds to existing spectrogram content) // Use for compositing multiple profiles (e.g., Gaussian + Noise) // Parameters same as draw_bezier_curve() -void draw_bezier_curve_add(float* spectrogram, - int dct_size, - int num_frames, - const float* control_frames, - const float* control_freqs_hz, - const float* control_amps, - int n_control_points, - ProfileType profile_type, - float profile_param1, - float profile_param2 = 0.0f); +void draw_bezier_curve_add(float* spectrogram, int dct_size, int num_frames, + const float* control_frames, + const float* control_freqs_hz, + const float* control_amps, int n_control_points, + ProfileType profile_type, float profile_param1, + float profile_param2 = 0.0f); // Evaluate vertical profile at given distance from central curve // type: Profile type (Gaussian, Decaying Sinusoid, Noise) @@ -67,9 +60,7 @@ void draw_bezier_curve_add(float* spectrogram, // param1: First profile parameter // param2: Second profile parameter // Returns: Profile amplitude at given distance (0.0-1.0 range typically) -float evaluate_profile(ProfileType type, - float distance, - float param1, +float evaluate_profile(ProfileType type, float distance, float param1, float param2); // Home-brew deterministic RNG for noise profile @@ -77,4 +68,3 @@ float evaluate_profile(ProfileType type, // seed: Input seed value // Returns: Pseudo-random uint32_t value uint32_t spectral_brush_rand(uint32_t seed); - |