SpaceCadetPinball/SpaceCadetPinball/TSound.cpp
Patrice Levesque a4c6165094
Implement stereo sound. (#138)
* Implement stereo sound.

Original Space Cadet has mono sound.  To achieve stereo, the following
steps were accomplished:

- Add a game option to turn on/off stereo sound.  Default is on.

- TPinballComponent objects were extended with a method called
  get_coordinates() that returns a single 2D point, approximating the
  on-screen position of the object, re-mapped between 0 and 1 vertically
  and horizontally, {0, 0} being at the top-left.

    - For static objects like bumpers and lights, the coordinate refers
      to the geometric center of the corresponding graphic sprite, and
      is precalculated at initialization.

    - For ball objects, the coordinate refers to the geometric center of
      the ball, calculated during play when requested.

- Extend all calls to sound-playing methods so that they include a
  TPinballComponent* argument that refers to the sound source, e.g.
  where the sound comes from.  For instance, when a flipper is
  activated, its method call to emit a sound now includes a reference to
  the flipper object; when a ball goes under a SkillShotGate, its method
  call to emit a sound now includes a reference to the corresponding
  light; and so on.

  For some cases, like light rollovers, the sound source is taken from
  the ball that triggered the light rollover.

  For other cases, like holes, flags and targets, the sound source is
  taken from the object itself.

  For some special cases like ramp activation, sound source is
  taken from the nearest light position that makes sense.

  For all game-progress sounds, like mission completion sounds or ball
  drain sounds, the sound source is undefined (set to nullptr), and the
  Sound::PlaySound() method takes care of positioning them at a default
  location, where speakers on a pinball machine normally are.

- Make the Sound::PlaySound() method accept a new argument, a
  TPinballComponent reference, as described above.

  If the stereo option is turned on, the Sound::PlaySound() method calls
  the get_coordinates() method of the TPinballComponent reference to get
  the sound position.

  This project uses SDL_mixer and there is a function called
  Mix_SetPosition() that allows placing a sound in the stereo field, by
  giving it a distance and an angle.

  We arbitrarily place the player's ears at the bottom of the table; we
  set the ears' height to half a table's length.  Intensity of the
  stereo effect is directly related to this value; the farther the
  player's ears from the table, the narrowest the stereo picture gets,
  and vice-versa.

  From there we have all we need to calculate distance and angle; we do
  just that and position all the sounds.

* Copy-paste typo fix.
2022-05-30 10:35:29 +03:00

17 lines
411 B
C++

#include "pch.h"
#include "TSound.h"
#include "loader.h"
TSound::TSound(TPinballTable* table, int groupIndex) : TPinballComponent(table, groupIndex, true)
{
visualStruct visual{};
loader::query_visual(groupIndex, 0, &visual);
this->SoundIndex = visual.SoundIndex4;
}
float TSound::Play(TPinballComponent *soundSource, const char* info)
{
return loader::play_sound(this->SoundIndex, soundSource, info);
}