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Spinout functions (#762)

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* Document steering

* Refer to steering position, instead of steering angle

Refer to steering position instead of steering angle, to make clear that it is not the same thing as degrees.

* Change comment to block format

* Pre-spinout swerving

When you sharply move a joystick in 150CC or hit a banana, you can enter a pre-spinout state where you swerve back and forth.

This primarily documents how the swerving works, as well as updating some related function / property names
This commit is contained in:
Jed Grabman
2026-04-15 21:38:48 -04:00
committed by GitHub
parent c68b3d481f
commit bb8d234152
8 changed files with 123 additions and 113 deletions
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src/effects.c
+90 -80
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@@ -152,13 +152,13 @@ void clean_effect(Player* player, s8 playerIndex) {
if (((player->effects & BANANA_SPINOUT_EFFECT) == BANANA_SPINOUT_EFFECT) ||
(player->effects & DRIVING_SPINOUT_EFFECT) == DRIVING_SPINOUT_EFFECT) {
func_8008C8C4(player, playerIndex);
remove_spinout_effects(player, playerIndex);
}
if ((player->effects & BANANA_NEAR_SPINOUT_EFFECT) == BANANA_NEAR_SPINOUT_EFFECT) {
func_8008D0E4(player, playerIndex);
remove_banana_near_spinout_effect(player, playerIndex);
}
if ((player->kartProps & DRIVING_SPINOUT) != 0) {
func_8008D3B0(player, playerIndex);
if ((player->kartProps & DRIVING_NEAR_SPINOUT) != 0) {
remove_driving_near_spinout_effect(player, playerIndex);
}
if ((player->effects & MUSHROOM_EFFECT) == MUSHROOM_EFFECT) {
remove_mushroom_effect(player);
@@ -257,13 +257,13 @@ void func_8008C6D0(Player* player, s8 playerIndex) {
player->unk_042 = 0;
}
void func_8008C73C(Player* player, s8 playerIndex) {
void add_spinout_effect(Player* player, s8 playerIndex) {
clean_effect(player, playerIndex);
if (((player->effects & BANANA_SPINOUT_EFFECT) != BANANA_SPINOUT_EFFECT) &&
((player->effects & DRIVING_SPINOUT_EFFECT) != DRIVING_SPINOUT_EFFECT)) {
player->effects &= ~DRIFTING_EFFECT;
if ((player->unk_0C0 / 182) >= 0) {
if ((player->unk_0C0 / DEGREES_CONVERSION_FACTOR) >= 0) {
player->effects |= DRIVING_SPINOUT_EFFECT;
} else {
player->effects |= BANANA_SPINOUT_EFFECT;
@@ -293,7 +293,7 @@ void func_8008C73C(Player* player, s8 playerIndex) {
}
}
void func_8008C8C4(Player* player, s8 playerId) {
void remove_spinout_effects(Player* player, s8 playerId) {
player->effects &= ~BANANA_SPINOUT_EFFECT;
player->effects &= ~DRIVING_SPINOUT_EFFECT;
player->unk_0A8 = 0;
@@ -347,7 +347,7 @@ void func_8008C9EC(Player* player, s8 playerIndex) {
if (gModeSelection == BATTLE) {
pop_player_balloon(player, playerIndex);
}
func_8008C8C4(player, playerIndex);
remove_spinout_effects(player, playerIndex);
}
}
} else {
@@ -357,7 +357,7 @@ void func_8008C9EC(Player* player, s8 playerIndex) {
if (stackPadding2 == 0) {
player->unk_0B2--;
if (player->unk_0B2 <= 0) {
func_8008C8C4(player, playerIndex);
remove_spinout_effects(player, playerIndex);
if (gModeSelection == BATTLE) {
pop_player_balloon(player, playerIndex);
}
@@ -372,141 +372,151 @@ void func_8008C9EC(Player* player, s8 playerIndex) {
}
}
void func_8008CDC0(Player* player, s8 playerIndex) {
void trigger_hit_banana(Player* player, s8 playerIndex) {
clean_effect(player, playerIndex);
player->triggers &= ~HIT_BANANA_TRIGGER;
player->unk_0B4 = 0;
player->unk_0B8 = 3.0f;
player->unk_0AC = 1;
player->swerveTimer = 0;
player->swerveAccelInit = 3.0f;
player->swerveDirection = 1;
player->effects &= ~DRIFTING_EFFECT;
if (((player->steerPosition >> 16) >= 20) || ((player->steerPosition >> 16) <= -20) ||
(((player->speed / 18.0f) * 216.0f) <= 30.0f) || ((player->effects & MIDAIR_EFFECT) != 0) ||
(((player->type & PLAYER_HUMAN) == 0) && ((player->effects & LOST_RACE_EFFECT) == 0))) {
func_8008C73C(player, playerIndex);
add_spinout_effect(player, playerIndex);
} else {
player->effects |= BANANA_NEAR_SPINOUT_EFFECT;
}
}
void func_8008CEB0(Player* player, s8 playerIndex) {
f32 var_f0;
s16 var_v1;
s16 var_a3;
s16 temp_f16;
// almost identical to apply_driving_near_spinout_effect, see there for more documentation
void apply_banana_near_spinout_effect(Player* player, s8 playerIndex) {
f32 swerve_accel_init;
s16 swerve_timer;
s16 swerve_direction;
s16 swerve_velo_current;
var_f0 = player->unk_0B8;
var_v1 = player->unk_0B4;
var_a3 = player->unk_0AC;
var_v1++;
temp_f16 = (var_v1 * var_f0) - (0.2 * (var_v1 * var_v1));
if ((var_v1 != 0) && (temp_f16 < 0)) {
var_v1 = 0;
var_a3 = -var_a3;
var_f0 *= 0.8;
swerve_accel_init = player->swerveAccelInit;
swerve_timer = player->swerveTimer;
swerve_direction = player->swerveDirection;
swerve_timer++;
swerve_velo_current = (swerve_timer * swerve_accel_init) - (0.2 * (swerve_timer * swerve_timer));
if ((swerve_timer != 0) && (swerve_velo_current < 0)) {
swerve_timer = 0;
swerve_direction = -swerve_direction;
swerve_accel_init *= 0.8;
// requires braking to recover. A driving spinout allows just releasing gas as well
if ((player->effects & BRAKING_EFFECT) == BRAKING_EFFECT) {
player->effects |= BANANA_SPINOUT_SAVE_EFFECT;
}
if (var_f0 <= 1.0f) {
if (swerve_accel_init <= 1.0f) {
player->effects &= ~BANANA_NEAR_SPINOUT_EFFECT;
if ((player->effects & BANANA_SPINOUT_SAVE_EFFECT) != BANANA_SPINOUT_SAVE_EFFECT) {
func_8008C73C(player, playerIndex);
var_v1 = 0;
add_spinout_effect(player, playerIndex);
swerve_timer = 0;
} else {
player->kartGraphics |= WHISTLE;
player->effects &= ~BANANA_SPINOUT_SAVE_EFFECT;
if ((player->type & PLAYER_HUMAN) == PLAYER_HUMAN) {
func_800C90F4(playerIndex, (player->characterId * 0x10) + 0x29008008);
var_v1 = 0;
swerve_timer = 0;
}
}
}
}
temp_f16 *= var_a3;
if ((temp_f16 <= 0) && (var_a3 == 1)) {
temp_f16 = 0;
swerve_velo_current *= swerve_direction;
if ((swerve_velo_current <= 0) && (swerve_direction == 1)) {
swerve_velo_current = 0;
}
if ((temp_f16 >= 0) && (var_a3 == -1)) {
temp_f16 = 0;
if ((swerve_velo_current >= 0) && (swerve_direction == -1)) {
swerve_velo_current = 0;
}
player->unk_078 += temp_f16 * 0x12;
player->unk_0B8 = var_f0;
player->unk_0B4 = var_v1;
player->unk_0AC = var_a3;
player->unk_078 += swerve_velo_current * 18;
player->swerveAccelInit = swerve_accel_init;
player->swerveTimer = swerve_timer;
player->swerveDirection = swerve_direction;
if (player->effects & MIDAIR_EFFECT) {
func_8008C73C(player, playerIndex);
add_spinout_effect(player, playerIndex);
player->effects &= ~BANANA_NEAR_SPINOUT_EFFECT;
}
}
void func_8008D0E4(Player* player, UNUSED s8 playerIndex) {
void remove_banana_near_spinout_effect(Player* player, UNUSED s8 playerIndex) {
player->effects &= ~BANANA_NEAR_SPINOUT_EFFECT;
}
void func_8008D0FC(Player* player, s8 playerIndex) {
void trigger_driving_spinout(Player* player, s8 playerIndex) {
clean_effect(player, playerIndex);
player->triggers &= ~DRIVING_SPINOUT_TRIGGER;
player->unk_0B4 = 0;
player->unk_0B8 = 2.0f;
player->unk_0AC = 1;
player->swerveTimer = 0;
player->swerveAccelInit = 2.0f;
player->swerveDirection = 1;
player->effects &= ~DRIFTING_EFFECT;
player->kartProps |= DRIVING_SPINOUT;
player->kartProps |= DRIVING_NEAR_SPINOUT;
}
void func_8008D170(Player* player, s8 playerIndex) {
f32 var_f0;
s16 var_v1;
s16 var_a3;
s16 temp_f16;
void apply_driving_near_spinout_effect(Player* player, s8 playerIndex) {
f32 swerve_accel_init;
s16 swerve_timer;
s16 swerve_direction;
s16 swerve_velo_current;
var_f0 = player->unk_0B8;
var_v1 = player->unk_0B4;
var_a3 = player->unk_0AC;
var_v1++;
temp_f16 = (var_v1 * var_f0) - (0.1 * (var_v1 * var_v1));
if ((var_v1 != 0) && (temp_f16 < 0)) {
var_v1 = 0;
var_a3 = -var_a3;
var_f0 *= 0.9;
// These properties are only used for swerving before spinouts
swerve_accel_init = player->swerveAccelInit;
swerve_timer = player->swerveTimer;
swerve_direction = player->swerveDirection;
swerve_timer++;
// Standard physics formula: Velo_current = velo_init + (accel_init * time) + (accel_jerk * time**2) / 2
swerve_velo_current = (swerve_accel_init * swerve_timer) - (0.1 * (swerve_timer * swerve_timer));
// Once one swerve finishes, setup to start a smaller one in the opposite direction
if ((swerve_timer != 0) && (swerve_velo_current < 0)) { // (10 * swerve_accel_init < swerve_timer))
swerve_timer = 0;
swerve_direction = -swerve_direction;
swerve_accel_init *= 0.9;
if (((player->effects & BRAKING_EFFECT) == BRAKING_EFFECT) || !(player->kartProps & THROTTLE)) {
player->effects |= BANANA_SPINOUT_SAVE_EFFECT;
}
if (var_f0 <= 1.3) {
player->kartProps &= ~DRIVING_SPINOUT;
// stop swerving once they are small enough
if (swerve_accel_init <= 1.3) {
player->kartProps &= ~DRIVING_NEAR_SPINOUT;
if ((player->effects & BANANA_SPINOUT_SAVE_EFFECT) != BANANA_SPINOUT_SAVE_EFFECT) {
func_8008C73C(player, playerIndex);
var_v1 = 0;
add_spinout_effect(player, playerIndex);
swerve_timer = 0;
} else {
player->kartGraphics |= WHISTLE;
player->effects &= ~BANANA_SPINOUT_SAVE_EFFECT;
if ((player->type & PLAYER_HUMAN) == PLAYER_HUMAN) {
func_800C90F4(playerIndex, (player->characterId * 0x10) + 0x29008008);
var_v1 = 0;
swerve_timer = 0;
}
}
}
}
temp_f16 *= var_a3;
if ((temp_f16 <= 0) && (var_a3 == 1)) {
temp_f16 = 0;
swerve_velo_current *= swerve_direction;
if ((swerve_velo_current <= 0) && (swerve_direction == 1)) {
swerve_velo_current = 0;
}
if ((temp_f16 >= 0) && (var_a3 == -1)) {
temp_f16 = 0;
if ((swerve_velo_current >= 0) && (swerve_direction == -1)) {
swerve_velo_current = 0;
}
player->unk_078 += temp_f16 * 0x14;
player->unk_0B8 = var_f0;
player->unk_0B4 = var_v1;
player->unk_0AC = var_a3;
/* unk_078 contributes to rotational velocity (spin). It looks to be set each frame in steering code
(e.g. func_80033AE0), so it does not accumulate values from swerve_velo_current over multiple frames */
player->unk_078 += swerve_velo_current * 20;
player->swerveAccelInit = swerve_accel_init;
player->swerveTimer = swerve_timer;
player->swerveDirection = swerve_direction;
if (player->effects & MIDAIR_EFFECT) {
func_8008C73C(player, playerIndex);
player->kartProps &= ~DRIVING_SPINOUT;
add_spinout_effect(player, playerIndex);
player->kartProps &= ~DRIVING_NEAR_SPINOUT;
}
}
void func_8008D3B0(Player* player, UNUSED s8 playerIndex) {
player->kartProps &= ~DRIVING_SPINOUT;
void remove_driving_near_spinout_effect(Player* player, UNUSED s8 playerIndex) {
player->kartProps &= ~DRIVING_NEAR_SPINOUT;
}
void trigger_shroom(Player* player, s8 playerIndex) {