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#pragma once
#include "cgltf.h"
#include "darray.h"
#include "defines.h"
#include "maths_types.h"
#include "ral_types.h"
typedef enum Interpolation {
INTERPOLATION_STEP,
INTERPOLATION_LINEAR,
INTERPOLATION_CUBIC, /** @brief Cubic spline interpolation */
INTERPOLATION_COUNT
} Interpolation;
typedef enum KeyframeKind {
KEYFRAME_ROTATION,
KEYFRAME_TRANSLATION,
KEYFRAME_SCALE,
KEYFRAME_WEIGHTS,
} KeyframeKind;
static const char* keyframe_kind_strings[4] = { "ROTATION", "TRANSLATION", "SCALE", "WEIGHTS"};
typedef union Keyframe {
Quat rotation;
Vec3 translation;
Vec3 scale;
f32 weights[4];
} Keyframe;
typedef struct Keyframes {
KeyframeKind kind;
Keyframe* values;
size_t count;
} Keyframes;
typedef struct Joint {
// used instead of pointers later to update correct joints
size_t node_idx;
ssize_t parent; // parent bone. -1 means its the root
size_t children[8]; // children bones, upto 8
u8 children_count;
char* debug_label; // optional
Mat4 inverse_bind_matrix;
Mat4 local_transform;
/** @brief holds position, rotation, and scale that will be written to by animation
samplers every tick of the animation system. */
Transform transform_components;
} Joint;
#ifndef TYPED_JOINT_ARRAY
KITC_DECL_TYPED_ARRAY(Joint);
#define TYPED_JOINT_ARRAY
#endif
typedef u32 JointIdx;
typedef struct Armature {
char* label;
Joint_darray* joints;
} Armature;
// NOTE: I think we will need to topologically sort the joints to store them in array if we want to
// do linear array traversal
// when calculating transforms.
typedef struct AnimationSpline {
f32* timestamps;
size_t n_timestamps;
Keyframes values;
Interpolation interpolation;
} AnimationSpline;
// combines a sampler and a channel in gltf
typedef struct AnimationSampler {
int current_index;
f32 min;
f32 max;
AnimationSpline animation;
u32 target_joint_idx; // index into the array of joints in an armature
} AnimationSampler;
#ifndef TYPED_ANIM_SAMPLER_ARRAY
KITC_DECL_TYPED_ARRAY(AnimationSampler);
#define TYPED_ANIM_SAMPLER_ARRAY
#endif
/** @brief Sample an animation at a given time `t` returning an interpolated keyframe */
PUB Keyframe Animation_Sample(AnimationSampler* sampler, f32 t);
/** @brief A clip contains one or more animation curves. */
typedef struct AnimationClip {
const char* clip_name;
bool is_playing;
f32 time;
AnimationSampler_darray* channels;
} AnimationClip;
#ifndef TYPED_ANIM_CLIP_ARRAY
KITC_DECL_TYPED_ARRAY(AnimationClip);
#define TYPED_ANIM_CLIP_ARRAY
#endif
// typedef struct SkinnedAnimation {
// Mat4* joint_matrices;
// size_t n_joints;
// } SkinnedAnimation;
PUB void Animation_Play(AnimationClip* clip);
void Animation_Tick(AnimationClip* clip, Armature* armature, f32 delta_time);
void Animation_VisualiseJoints(Armature* armature);
#define MAX_BONES 100
typedef struct AnimDataUniform {
Mat4 bone_matrices[MAX_BONES];
} AnimDataUniform;
ShaderDataLayout AnimData_GetLayout(void* data);
// Animation Targets:
// - Mesh
// - Joint
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