create immediate mode animation for tsoding

Author: ratchetfreak

nob.c

@@ -122,6 +122,7 @@ int main(int argc, char **argv)
     if (!build_plug_c(force, PLUGS_DIR"template/plug.c", BUILD_DIR"libtemplate.so")) return 1;
     if (!build_plug_c(force, PLUGS_DIR"squares/plug.c", BUILD_DIR"libsquare.so")) return 1;
     if (!build_plug_c(force, PLUGS_DIR"tsoding/plug.c", BUILD_DIR"libtsoding.so")) return 1;
+    if (!build_plug_c(force, PLUGS_DIR"imtsoding/plug.c", BUILD_DIR"libimtsoding.so")) return 1;
     if (!build_plug_c(force, PLUGS_DIR"bezier/plug.c", BUILD_DIR"libbezier.so")) return 1;
     if (!build_plug_cxx(force, PLUGS_DIR"cpp/plug.cpp", BUILD_DIR"libcpp.so")) return 1;
 

plugs/imtsoding/imanim.c

@@ -0,0 +1,68 @@
+
+
+float clipTime(AnimState *a, float duration) {
+    float timeSinceStart = a->currentTime - a->clipStartTime;
+    float animT = timeSinceStart / duration;
+    if(animT < 0) //before the clip requested
+        animT = 0.f;
+    if(animT > 1) //after the clip requested
+        animT = 1.f;
+
+    if(a->globEnd < (a->clipStartTime + duration))
+        a->globEnd = a->clipStartTime + duration;
+
+    return animT;
+}
+float prevClipTime(AnimState *a, float duration) {
+    float timeSinceStart = a->currentTime - a->deltaTime - a->clipStartTime;
+    float animT = timeSinceStart / duration;
+    if(animT < 0) //before the clip requested
+        animT = 0.f;
+    if(animT > 1) //after the clip requested
+        animT = 1.f;
+
+    if(a->globEnd < (a->clipStartTime + duration))
+        a->globEnd = a->clipStartTime + duration;
+
+    return animT;
+}
+
+void anim_wait(AnimState *a, float duration) {
+    if(a->globEnd < (a->clipStartTime + duration))
+        a->globEnd = a->clipStartTime + duration;
+    a->clipStartTime = a->globEnd;
+}
+
+void wait_for_end(AnimState *a){
+	a->clipStartTime = a->globEnd;
+}
+
+void anim_move_scalar(AnimState *anim, float *src, float dst, float duration, Interp_Func func)
+{
+    float t = interp_func(func, clipTime(anim, duration));
+    if(t<=0.0f) return;
+    if(t>=1.0f) {
+        *src = dst; return;
+    }
+    *src = Lerp(*src, dst, t);
+}
+
+void anim_move_vec2(AnimState *anim, Vector2 *src, Vector2 dst, float duration, Interp_Func func)
+{
+    float t = interp_func(func, clipTime(anim, duration));
+    if(t<=0.0f) return;
+    if(t>=1.0f) {
+        *src = dst; return;
+    }
+    *src = Vector2Lerp(*src, dst, t);
+}
+
+void anim_move_vec4(AnimState *anim, Vector4 *src, Vector4 dst, float duration, Interp_Func func)
+{
+    float t = interp_func(func, clipTime(anim, duration));
+    if(t<=0.0f) return;
+    if(t>=1.0f) {
+        *src = dst; return;
+    }
+    *src = Vector4Lerp(*src, dst, t);
+}

plugs/imtsoding/imanim.h

@@ -0,0 +1,49 @@
+#include "interpolators.h"
+#include <raymath.h>
+
+typedef struct {
+    float currentTime; // time since start of the animation, increment with deltaTime every frame
+    float clipStartTime; // where the code is in the animation, only updated by a "wait" operation, reset every frame.
+    float globEnd; // when the animation ends, updated by clipTime, reset every frame.
+    float deltaTime;
+
+} AnimState;
+
+/*
+* returns a value between [0.0, 1.0] representing at which point 
+* the current time the animation is in.
+* a 0.0 return value represents that the current clip hasn't started yet 
+* a 1.0 return value represents that the current clip is fully finished
+* 
+* updates the globEnd value used in wait_for_end
+*/
+float clipTime(AnimState *a, float duration);
+
+/*
+* returns a value between [0.0, 1.0] representing at which point 
+* the time the animation was in last frame.
+*
+* updates the globEnd value used in wait_for_end
+*
+* this is useful for sound triggers
+*
+*     if(clipTime(anim, 0.1f) > 0 && prevClipTime(anim, 0.1f) == 0.0)
+*         p->env.play_sound(p->kick_sound, p->kick_wave);
+*/
+float prevClipTime(AnimState *a, float duration);
+
+/*
+* advances the clipStartTime 
+*/
+void anim_wait(AnimState *a, float duration) ;
+void wait_for_end(AnimState *a);
+
+/*
+* utilities for interpolating floats using clipTime(anim, duration)
+* 
+* if clipTime would return 0.0f it is a noop
+* if clipTime(anim, duration) would return 1.0f does `*src = dst;`
+*/
+void anim_move_scalar(AnimState *anim, float *src, float dst, float duration, Interp_Func func);
+void anim_move_vec2(AnimState *anim, Vector2 *src, Vector2 dst, float duration, Interp_Func func);
+void anim_move_vec4(AnimState *anim, Vector4 *src, Vector4 dst, float duration, Interp_Func func);

plugs/imtsoding/interpolators.h

@@ -0,0 +1,83 @@
+#ifndef INTERPOLATORS_H_
+#define INTERPOLATORS_H_
+
+#include <assert.h>
+#include <math.h>
+#include <raymath.h>
+
+typedef enum {
+    FUNC_ID,
+    FUNC_SINSTEP,
+    FUNC_SMOOTHSTEP,
+    FUNC_SQR,
+    FUNC_SQRT,
+    FUNC_SINPULSE,
+} Interp_Func;
+
+static inline float smoothstep(float x)
+{
+    if (x < 0.0) return 0.0;
+    if (x >= 1.0) return 1.0;
+    return 3*x*x - 2*x*x*x;
+}
+
+static inline float sinstep(float t)
+{
+    if (t < 0.0) return 0.0;
+    if (t >= 1.0) return 1.0;
+    return (sinf(PI*t - PI*0.5) + 1)*0.5;
+}
+
+static inline float sinpulse(float t)
+{
+    if (t < 0.0) return 0.0;
+    if (t >= 1.0) return 0.0;
+    return sinf(PI*t);
+}
+
+static inline Vector2 cubic_bezier(float t, Vector2 nodes[4])
+{
+    float it = 1 - t;
+    Vector2 b = Vector2Scale(nodes[0], it*it*it);
+    b = Vector2Add(b, Vector2Scale(nodes[1], 3*it*it*t));
+    b = Vector2Add(b, Vector2Scale(nodes[2], 3*it*t*t));
+    b = Vector2Add(b, Vector2Scale(nodes[3], t*t*t));
+    return b;
+}
+
+static inline Vector2 cubic_bezier_der(float t, Vector2 nodes[4])
+{
+    float it = 1 - t;
+    Vector2 b = Vector2Scale(nodes[0], -3*it*it);
+    b = Vector2Add(b, Vector2Scale(nodes[1], 3*it*it));
+    b = Vector2Add(b, Vector2Scale(nodes[1], -6*it*t));
+    b = Vector2Add(b, Vector2Scale(nodes[2], 6*it*t));
+    b = Vector2Add(b, Vector2Scale(nodes[2], -3*t*t));
+    b = Vector2Add(b, Vector2Scale(nodes[3], 3*t*t));
+    return b;
+}
+
+static inline float cuber_bezier_newton(float x, Vector2 nodes[4], size_t n)
+{
+    float t = 0;
+    for (size_t i = 0; i < n; ++i) {
+        t = t - (cubic_bezier(t, nodes).x - x)/cubic_bezier_der(t, nodes).x;
+    }
+    return t;
+}
+
+static inline float interp_func(Interp_Func func, float t)
+{
+    switch (func) {
+    case FUNC_ID:         return t;
+    case FUNC_SQR:        return t*t;
+    case FUNC_SQRT:       return sqrtf(t);
+    case FUNC_SINSTEP:    return sinstep(t);
+    case FUNC_SMOOTHSTEP: return smoothstep(t);
+    case FUNC_SINPULSE:   return sinpulse(t);
+    }
+    assert(0 && "UNREACHABLE");
+    return 0.0f;
+}
+
+#endif // INTERPOLATORS_H_