Merge branch 'broly-ease' into 'master'

Use sinusoidial interpolation for Broly ki

See merge request KartKrew/Kart!811

src/k_objects.h

@@ -56,5 +56,6 @@ void Obj_DuelBombInit(mobj_t *bomb);
 
 /* Broly Ki */
 mobj_t *Obj_SpawnBrolyKi(mobj_t *source, tic_t duration);
+void Obj_BrolyKiThink(mobj_t *ki);
 
 #endif/*k_objects_H*/

src/objects/broly.c

@@ -2,9 +2,33 @@
 #include "../info.h"
 #include "../k_kart.h"
 #include "../k_objects.h"
+#include "../m_easing.h"
 #include "../p_local.h"
 #include "../s_sound.h"
 
+// TODO: generic function
+static void P_InstaScale(mobj_t *thing, fixed_t scale)
+{
+	P_SetScale(thing, scale);
+	thing->destscale = scale;
+}
+
+/* An object may not be visible on the same tic:
+   1) that it spawned
+   2) that it cycles to the next state */
+#define BUFFER_TICS (2)
+
+#define broly_duration(o) ((o)->extravalue1)
+#define broly_maxscale(o) ((o)->extravalue2)
+
+static inline fixed_t
+get_unit_linear (const mobj_t *x)
+{
+	const tic_t t = (x->tics - BUFFER_TICS);
+
+	return t * FRACUNIT / broly_duration(x);
+}
+
 mobj_t *
 Obj_SpawnBrolyKi
 (		mobj_t * source,
@@ -25,13 +49,10 @@ Obj_SpawnBrolyKi
 	x->color = source->color;
 	x->hitlag = 0; // do not copy source hitlag
 
-	P_SetScale(x, 64 * mapobjectscale);
+	broly_maxscale(x) = 64 * mapobjectscale;
-	x->scalespeed = x->scale / duration;
+	broly_duration(x) = duration;
 
-	// The last tic doesn't actually get rendered so in order
+	x->tics = (duration + BUFFER_TICS);
-	// to show scale = destscale, add one buffer tic.
-	x->tics = (duration + 1);
-	x->destscale = 1; // 0 also doesn't work
 
 	K_ReduceVFX(x, NULL);
 
@@ -39,3 +60,13 @@ Obj_SpawnBrolyKi
 
 	return x;
 }
+
+void
+Obj_BrolyKiThink (mobj_t *x)
+{
+	const fixed_t
+		t = get_unit_linear(x),
+		n = Easing_OutSine(t, 0, broly_maxscale(x));
+
+	P_InstaScale(x, n);
+}

src/p_mobj.c

@@ -6508,6 +6508,9 @@ static void P_MobjSceneryThink(mobj_t *mobj)
 	case MT_DRIFTELECTRICSPARK:
 		mobj->renderflags ^= RF_DONTDRAW;
 		break;
+	case MT_BROLY:
+		Obj_BrolyKiThink(mobj);
+		break;
 	case MT_VWREF:
 	case MT_VWREB:
 	{