Walking

The walking action occurs when Mario is moving only by using the analog stick. It can also occur when exiting water (except if exiting water through a water jump). When walking:

1. mario_drop_held_object
2. if should_begin_sliding; Begin Sliding
3. if INPUT_FIRST_PERSON:
   1. mario_drop_held_object
   2. if actionState == 1; Standing Against Wall
   3. if forwardVel >= 16 and m->floor->normal.y >= 0.17364818; Braking
   4. else; Decelerating
4. if INPUT_A_PRESSED; (todo; see ref)
5. if INPUT_B_PRESSED;
   1. if forwardVel >= 29 and stickMag > 48; yVel=20; Dive
   2. else; Move Punching
6. if INPUT_UNKNOWN_5 (aka neutral joystick: https://ukikipedia.net/mediawiki/index.php?title=Turning_Around&oldid=17030); (same code as INPUT_FIRST_PERSON)
7. if analog_stick_held_back and forwardVel >= 16; Turning Around
8. if INPUT_Z_PRESSED; Crouch Slide
9. update_walking_speed
10. case GROUND_STEP_LEFT_GROUND; Freefall
11. case GROUND_STEP_HIT_WALL; push_or_sidle_wall

Walking
Properties
Hex	todo
Action Flags	todo
Action Group	Moving
ID	todo

Mario's speed during the first 45 frames (1.5 seconds) of walking. Note that this depends on the slope of the surface being walked on.

Here's what update_walking_speed is for convenience:

void update_walking_speed(struct MarioState *m) {
    f32 maxTargetSpeed;
    f32 targetSpeed;

    if (m->floor != NULL && m->floor->type == SURFACE_SLOW) {
        maxTargetSpeed = 24.0f;
    } else {
        maxTargetSpeed = 32.0f;
    }

    targetSpeed = m->intendedMag < maxTargetSpeed ? m->intendedMag : maxTargetSpeed;

    if (m->quicksandDepth > 10.0f) {
        targetSpeed *= 6.25 / m->quicksandDepth;
    }

    if (m->forwardVel <= 0.0f) {
        m->forwardVel += 1.1f;
    } else if (m->forwardVel <= targetSpeed) {
        m->forwardVel += 1.1f - m->forwardVel / 43.0f;
    } else if (m->floor->normal.y >= 0.95f) {
        m->forwardVel -= 1.0f;
    }

    if (m->forwardVel > 48.0f) {
        m->forwardVel = 48.0f;
    }

    m->faceAngle[1] =
        m->intendedYaw - approach_s32((s16)(m->intendedYaw - m->faceAngle[1]), 0, 0x800, 0x800);
    apply_slope_accel(m);
}

/**
 * Return the value 'current' after it tries to approach target, going up at
 * most 'inc' and going down at most 'dec'.
 */
s32 approach_s32(s32 current, s32 target, s32 inc, s32 dec) {
    //! If target is close to the max or min s32, then it's possible to overflow
    // past it without stopping.

    if (current < target) {
        current += inc;
        if (current > target) {
            current = target;
        }
    } else {
        current -= dec;
        if (current < target) {
            current = target;
        }
    }
    return current;
}

void apply_slope_accel(struct MarioState *m) {
    f32 slopeAccel;

    struct Surface *floor = m->floor;
    f32 steepness = sqrtf(floor->normal.x * floor->normal.x + floor->normal.z * floor->normal.z);

    UNUSED f32 normalY = floor->normal.y;
    s16 floorDYaw = m->floorAngle - m->faceAngle[1];

    if (mario_floor_is_slope(m)) {
        s16 slopeClass = 0;

        if (m->action != ACT_SOFT_BACKWARD_GROUND_KB && m->action != ACT_SOFT_FORWARD_GROUND_KB) {
            slopeClass = mario_get_floor_class(m);
        }

        switch (slopeClass) {
            case SURFACE_CLASS_VERY_SLIPPERY:
                slopeAccel = 5.3f;
                break;
            case SURFACE_CLASS_SLIPPERY:
                slopeAccel = 2.7f;
                break;
            default:
                slopeAccel = 1.7f;
                break;
            case SURFACE_CLASS_NOT_SLIPPERY:
                slopeAccel = 0.0f;
                break;
        }

        if (floorDYaw > -0x4000 && floorDYaw < 0x4000) {
            m->forwardVel += slopeAccel * steepness;
        } else {
            m->forwardVel -= slopeAccel * steepness;
        }
    }

    m->slideYaw = m->faceAngle[1];

    m->slideVelX = m->forwardVel * sins(m->faceAngle[1]);
    m->slideVelZ = m->forwardVel * coss(m->faceAngle[1]);

    m->vel[0] = m->slideVelX;
    m->vel[1] = 0.0f;
    m->vel[2] = m->slideVelZ;

    mario_update_moving_sand(m);
    mario_update_windy_ground(m);
}

static s16 sMovingSandSpeeds[] = { 12, 8, 4, 0 };
u32 mario_update_moving_sand(struct MarioState *m) {
    struct Surface *floor = m->floor;
    s32 floorType = floor->type;

    if (floorType == SURFACE_DEEP_MOVING_QUICKSAND || floorType == SURFACE_SHALLOW_MOVING_QUICKSAND
        || floorType == SURFACE_MOVING_QUICKSAND || floorType == SURFACE_INSTANT_MOVING_QUICKSAND) {
        s16 pushAngle = floor->force << 8;
        f32 pushSpeed = sMovingSandSpeeds[floor->force >> 8];

        m->vel[0] += pushSpeed * sins(pushAngle);
        m->vel[2] += pushSpeed * coss(pushAngle);

        return TRUE;
    }

    return FALSE;
}

u32 mario_update_windy_ground(struct MarioState *m) {
    struct Surface *floor = m->floor;

    if (floor->type == SURFACE_HORIZONTAL_WIND) {
        f32 pushSpeed;
        s16 pushAngle = floor->force << 8;

        if (m->action & ACT_FLAG_MOVING) {
            s16 pushDYaw = m->faceAngle[1] - pushAngle;

            pushSpeed = m->forwardVel > 0.0f ? -m->forwardVel * 0.5f : -8.0f;

            if (pushDYaw > -0x4000 && pushDYaw < 0x4000) {
                pushSpeed *= -1.0f;
            }

            pushSpeed *= coss(pushDYaw);
        } else {
            pushSpeed = 3.2f + (gGlobalTimer % 4);
        }

        m->vel[0] += pushSpeed * sins(pushAngle);
        m->vel[2] += pushSpeed * coss(pushAngle);

#ifdef VERSION_JP
        play_sound(SOUND_ENV_WIND2, m->marioObj->header.gfx.cameraToObject);
#endif
        return TRUE;
    }

    return FALSE;
}