sm64

amp.inc.c (11367B)

---

 
 /**
  * Behavior for bhvHomingAmp and bhvCirclingAmp.
  * These are distinct objects; one chases (homes in on) Mario,
  * while the other circles around a fixed location with a radius
  * of 200, 300, 400, or 0 (stationary).
  */
 
 static struct ObjectHitbox sAmpHitbox = {
     /* interactType:      */ INTERACT_SHOCK,
     /* downOffset:        */ 40,
     /* damageOrCoinValue: */ 1,
     /* health:            */ 0,
     /* numLootCoins:      */ 0,
     /* radius:            */ 40,
     /* height:            */ 50,
     /* hurtboxRadius:     */ 50,
     /* hurtboxHeight:     */ 60,
 };
 
 /**
  * Homing amp initialization function.
  */
 void bhv_homing_amp_init(void) {
     o->oHomeX = o->oPosX;
     o->oHomeY = o->oPosY;
     o->oHomeZ = o->oPosZ;
     o->oGravity = 0.0f;
     o->oFriction = 1.0f;
     o->oBuoyancy = 1.0f;
     o->oHomingAmpAvgY = o->oHomeY;
 
     // Homing amps start at 1/10th their normal size.
     // They grow when they "appear" to Mario.
     cur_obj_scale(0.1f);
 
     // Hide the amp (until Mario gets near).
     o->header.gfx.node.flags |= GRAPH_RENDER_INVISIBLE;
 }
 
 /**
  * Amps' attack handler, shared by both types of amp.
  */
 static void check_amp_attack(void) {
     // Strange placement for this call. The hitbox is never cleared.
     // For perspective, this code is run every frame of bhv_circling_amp_loop
     // and every frame of a homing amp's HOMING_AMP_ACT_CHASE action.
     obj_set_hitbox(o, &sAmpHitbox);
 
     if (o->oInteractStatus & INT_STATUS_INTERACTED) {
         // Unnecessary if statement, maybe caused by a macro for
         //     if (o->oInteractStatus & INT_STATUS_INTERACTED) {
         //         o->oAction = X;
         //     }
         // ?
         if (o->oInteractStatus & INT_STATUS_INTERACTED) {
             // This function is used for both normal amps and homing amps,
             // AMP_ACT_ATTACK_COOLDOWN == HOMING_AMP_ACT_ATTACK_COOLDOWN
             o->oAction = AMP_ACT_ATTACK_COOLDOWN;
         }
 
         // Clear interact status
         o->oInteractStatus = 0;
     }
 }
 
 /**
  * Unhide the amp and grow until normal size, then begin chasing Mario.
  */
 static void homing_amp_appear_loop(void) {
     // gLakituState.goalPos is the position lakitu is moving towards.
     // In Lakitu and Mario cam, it is usually very close to the current camera position.
     // In Fixed cam, it is the point behind Mario the camera will go to when transitioning
     // to Lakitu cam. Homing amps will point themselves towards this point when appearing.
     f32 relativeTargetX = gLakituState.goalPos[0] - o->oPosX;
     f32 relativeTargetZ = gLakituState.goalPos[2] - o->oPosZ;
     s16 targetYaw = atan2s(relativeTargetZ, relativeTargetX);
 
     o->oMoveAngleYaw = approach_s16_symmetric(o->oMoveAngleYaw, targetYaw, 0x1000);
 
     // For 30 frames, make the amp "appear" by increasing its size by 0.03 each frame,
     // except for the first frame (when oTimer == 0) because the expression in cur_obj_scale
     // evaluates to 0.1, which is the same as it was before. After 30 frames, it ends at
     // a scale factor of 0.97. The amp remains at 97% of its real height for 60 more frames.
     if (o->oTimer < 30) {
         cur_obj_scale(0.1 + 0.9 * (f32)(o->oTimer / 30.0f));
     } else {
         o->oAnimState = 1;
     }
 
     // Once the timer becomes greater than 90, i.e. 91 frames have passed,
     // reset the amp's size and start chasing Mario.
     if (o->oTimer > 90) {
         cur_obj_scale(1.0f);
         o->oAction = HOMING_AMP_ACT_CHASE;
         o->oAmpYPhase = 0;
     }
 }
 
 /**
  * Chase Mario.
  */
 static void homing_amp_chase_loop(void) {
     // Lock on to Mario if he ever goes within 11.25 degrees of the amp's line of sight
     if ((o->oAngleToMario - 0x400 < o->oMoveAngleYaw)
         && (o->oMoveAngleYaw < o->oAngleToMario + 0x400)) {
         o->oHomingAmpLockedOn = TRUE;
         o->oTimer = 0;
     }
 
     // If the amp is locked on to Mario, start "chasing" him by moving
     // in a straight line at 15 units/second for 32 frames.
     if (o->oHomingAmpLockedOn == TRUE) {
         o->oForwardVel = 15.0f;
 
         // Move the amp's average Y (the Y value it oscillates around) to align with
         // Mario's head. Mario's graphics' Y + 150 is around the top of his head.
         // Note that the average Y will slowly go down to approach his head if the amp
         // is above his head, but if the amp is below it will instantly snap up.
         if (o->oHomingAmpAvgY > gMarioObject->header.gfx.pos[1] + 150.0f) {
             o->oHomingAmpAvgY -= 10.0f;
         } else {
             o->oHomingAmpAvgY = gMarioObject->header.gfx.pos[1] + 150.0f;
         }
 
         if (o->oTimer > 30) {
             o->oHomingAmpLockedOn = FALSE;
         }
     } else {
         // If the amp is not locked on to Mario, move forward at 10 units/second
         // while curving towards him.
         o->oForwardVel = 10.0f;
 
         obj_turn_toward_object(o, gMarioObject, 16, 0x400);
 
         // The amp's average Y will approach Mario's graphical Y position + 250
         // at a rate of 10 units per frame. Interestingly, this is different from
         // the + 150 used while chasing him. Could this be a typo?
         if (o->oHomingAmpAvgY < gMarioObject->header.gfx.pos[1] + 250.0f) {
             o->oHomingAmpAvgY += 10.0f;
         }
     }
 
     // The amp's position will sinusoidally oscillate 40 units around its average Y.
     o->oPosY = o->oHomingAmpAvgY + sins(o->oAmpYPhase * 0x400) * 20.0f;
 
     // Handle attacks
     check_amp_attack();
 
     // Give up if Mario goes further than 1500 units from the amp's original position
     if (!is_point_within_radius_of_mario(o->oHomeX, o->oHomeY, o->oHomeZ, 1500)) {
         o->oAction = HOMING_AMP_ACT_GIVE_UP;
     }
 }
 
 /**
  * Give up on chasing Mario.
  */
 static void homing_amp_give_up_loop(void) {
     UNUSED u8 filler[8];
 
     // Move forward for 152 frames
     o->oForwardVel = 15.0f;
 
     if (o->oTimer > 150) {
         // Hide the amp and reset it back to its inactive state
         o->oPosX = o->oHomeX;
         o->oPosY = o->oHomeY;
         o->oPosZ = o->oHomeZ;
         o->header.gfx.node.flags |= GRAPH_RENDER_INVISIBLE;
         o->oAction = HOMING_AMP_ACT_INACTIVE;
         o->oAnimState = 0;
         o->oForwardVel = 0.0f;
         o->oHomingAmpAvgY = o->oHomeY;
     }
 }
 
 /**
  * Cool down after a successful attack, shared by both types of amp.
  */
 static void amp_attack_cooldown_loop(void) {
     // Turn intangible and wait for 90 frames before chasing Mario again after hitting him.
     o->header.gfx.animInfo.animFrame += 2;
     o->oForwardVel = 0.0f;
 
     cur_obj_become_intangible();
 
     if (o->oTimer > 30) {
         o->oAnimState = 0;
     }
 
     if (o->oTimer > 90) {
         o->oAnimState = 1;
         cur_obj_become_tangible();
         o->oAction = HOMING_AMP_ACT_CHASE;
     }
 }
 
 /**
  * Homing amp update function.
  */
 void bhv_homing_amp_loop(void) {
     switch (o->oAction) {
         case HOMING_AMP_ACT_INACTIVE:
             if (is_point_within_radius_of_mario(o->oHomeX, o->oHomeY, o->oHomeZ, 800) == TRUE) {
                 // Make the amp start to appear, and un-hide it.
                 o->oAction = HOMING_AMP_ACT_APPEAR;
                 o->header.gfx.node.flags &= ~GRAPH_RENDER_INVISIBLE;
             }
             break;
 
         case HOMING_AMP_ACT_APPEAR:
             homing_amp_appear_loop();
             break;
 
         case HOMING_AMP_ACT_CHASE:
             homing_amp_chase_loop();
             cur_obj_play_sound_1(SOUND_AIR_AMP_BUZZ);
             break;
 
         case HOMING_AMP_ACT_GIVE_UP:
             homing_amp_give_up_loop();
             break;
 
         case HOMING_AMP_ACT_ATTACK_COOLDOWN:
             amp_attack_cooldown_loop();
             break;
     }
 
     object_step();
 
     // Oscillate
     o->oAmpYPhase++;
 }
 
 /**
  * Circling amp initialization function.
  */
 void bhv_circling_amp_init(void) {
     o->oHomeX = o->oPosX;
     o->oHomeY = o->oPosY;
     o->oHomeZ = o->oPosZ;
     o->oAnimState = 1;
 
     // Determine the radius of the circling amp's circle
     switch (o->oBhvParams2ndByte) {
         case AMP_BP_ROT_RADIUS_200:
             o->oAmpRadiusOfRotation = 200.0f;
             break;
 
         case AMP_BP_ROT_RADIUS_300:
             o->oAmpRadiusOfRotation = 300.0f;
             break;
 
         case AMP_BP_ROT_RADIUS_400:
             o->oAmpRadiusOfRotation = 400.0f;
             break;
 
         case AMP_BP_ROT_RADIUS_0:
             break;
     }
 
     // Choose a random point along the amp's circle.
     // The amp's move angle represents its angle along the circle.
     o->oMoveAngleYaw = random_u16();
 
     o->oAction = AMP_ACT_IDLE;
 }
 
 /**
  * Main update function for fixed amps.
  * Fixed amps are a sub-species of circling amps, with circle radius 0.
  */
 static void fixed_circling_amp_idle_loop(void) {
     // Turn towards Mario, in both yaw and pitch.
     f32 xToMario = gMarioObject->header.gfx.pos[0] - o->oPosX;
     f32 yToMario = gMarioObject->header.gfx.pos[1] + 120.0f - o->oPosY;
     f32 zToMario = gMarioObject->header.gfx.pos[2] - o->oPosZ;
     s16 vAngleToMario = atan2s(sqrtf(xToMario * xToMario + zToMario * zToMario), -yToMario);
 
     obj_turn_toward_object(o, gMarioObject, 19, 0x1000);
     o->oFaceAnglePitch = approach_s16_symmetric(o->oFaceAnglePitch, vAngleToMario, 0x1000);
 
     // Oscillate 40 units up and down.
     // Interestingly, 0x458 (1112 in decimal) is a magic number with no apparent significance.
     // It is slightly larger than the 0x400 figure used for homing amps, which makes
     // fixed amps oscillate slightly quicker.
     // Also, this uses the cosine, which starts at 1 instead of 0.
     o->oPosY = o->oHomeY + coss(o->oAmpYPhase * 0x458) * 20.0f;
 
     // Handle attacks
     check_amp_attack();
 
     // Oscillate
     o->oAmpYPhase++;
 
     // Where there is a cur_obj_play_sound_1 call in the main circling amp update function,
     // there is nothing here. Fixed amps are the only amps that never play
     // the "amp buzzing" sound.
 }
 
 /**
  * Main update function for regular circling amps.
  */
 static void circling_amp_idle_loop(void) {
     // Move in a circle.
     // The Y oscillation uses the magic number 0x8B0 (2224), which is
     // twice that of the fixed amp. In other words, circling amps will
     // oscillate twice as fast. Also, unlike all other amps, circling
     // amps oscillate 60 units around their average Y instead of 40.
     o->oPosX = o->oHomeX + sins(o->oMoveAngleYaw) * o->oAmpRadiusOfRotation;
     o->oPosZ = o->oHomeZ + coss(o->oMoveAngleYaw) * o->oAmpRadiusOfRotation;
     o->oPosY = o->oHomeY + coss(o->oAmpYPhase * 0x8B0) * 30.0f;
     o->oMoveAngleYaw += 0x400;
     o->oFaceAngleYaw = o->oMoveAngleYaw + 0x4000;
 
     // Handle attacks
     check_amp_attack();
 
     // Oscillate
     o->oAmpYPhase++;
 
     cur_obj_play_sound_1(SOUND_AIR_AMP_BUZZ);
 }
 
 /**
  * Circling amp update function.
  * This calls the main update functions for both types of circling amps,
  * and calls the common amp cooldown function when the amp is cooling down.
  */
 void bhv_circling_amp_loop(void) {
     switch (o->oAction) {
         case AMP_ACT_IDLE:
             if (o->oBhvParams2ndByte == AMP_BP_ROT_RADIUS_0) {
                 fixed_circling_amp_idle_loop();
             } else {
                 circling_amp_idle_loop();
             }
             break;
 
         case AMP_ACT_ATTACK_COOLDOWN:
             amp_attack_cooldown_loop();
             break;
     }
 }