elemel/cannonball

2D physics puzzle game

cannonball's Issues

Create Geometry class for sharing display list

The current draw scheme causes the frame rate to drop when many new actors are drawn in a short period of time. Since e.g. most particle actors draw the same or similar geometries, the should share display lists. Adding a Geometry class also opens up for separating physics and graphics geometries.

The actor will still receive the draw() call, but may delegate to a Geometry, perhaps after applying transforms for position, rotation, scale, and special effects.

Restart the game or change level without exiting the program

Player should lose a life when the cannonball falls off the world

Grapple dynamic bodies

The grappling gun is currently limited to static bodies. Extend it to work on dynamic bodies as well.

Set start and goal in SVG

Load texture info from SVG patterns

Camera should limit display to physics world

Currently, e.g. the cannonball disappears in mid-air whan falling off the physics world. It would be better if it fell off-screen as well.

The view should reflect where on the level the cannonball is

As the cannonball approaches e.g. the lower right corner of the level, it should also approach the lower right corner of the screen.

Support both stroke and fill for paths

Convexify the path for filling and physics, and keep the original path for drawing the outline.

Impact particle effect

Generate particles when the cannonball receives a strong impact. Maybe this can be achieved using the contact result callback.

Better explosions

Explosions could generate smoke (rename jet particles to smoke), sparks, and fire. Also use invisible impulse particles?

Materials

Materials are specified in SVG with e.g. data "material: stone". Materials provide defaults for density, texture, and destructibility.

Apply impulses on cannonball and shot when firing

Grenades and jet particles should be propelled by impulses instead of directly setting the velocity. The corresponding counter-impulse should be applied on the cannonball.

Remove dependency on NumPy

No rush. But if Cannonball only uses NumPy for matrix multiplication, maybe it can do without it.

Fade particles

Fade particle alpha during lifetime.

Try raycast-based explosions

Explosions currently apply an impulse in the world center of the body, which does not give any rotation. Try doing raycasts and applying the impulse where the ray hits instead. If multiple rays hit a body, use their average. Try 16 rays per explosion to begin with.

Background images

Use large cloud images as Cannonball backgrounds for now. Parallax scrolling. Preferably load from SVG.

Normals for lighting

Calculate vertex normals before triangulating paths.

Soft-edged circle texture for particles

Linearize paths

Use Pyglet vertex lists

Requires implementing Path.triangulate(). Use triangulations for graphics and convexifications for physics.

Consider using PyOpenGL for tessellation

Fire grenade when the space key is released

Fire grenades longer when the space key is pressed for a longer period of time.

Skid particle effect

Generate skid particles when the tangential velocity of the cannonball at a contact is different from its linear velocity.

Use shape colors from SVG

Particle physics for explosions and jet beams

Replace RevoluteJoint actor hack with a proper Hinge actor

Normalize paths

Normalization reverses paths with negative areas and removes vertices with straight angles.

Physical cannons

Create Box2D bodies for all cannons and attach them to the cannonball body with prismatic joints. Also use damped springs for stability and recoil handling. Apply an impulse on the cannon when firing, corresponding to the impulse propelling the shot.

Remove TODO.txt

Upgrade existing cannons

Do something useful when you take e.g. a grenade launcher upgrade and already have a grenade launcher.

Grappling gun upgrade increases grappling range. Grenade launcher upgrade increases max firing range. Jet engine upgrade could increase flight range (to be implemented).

Try attaching the camera to the cannonball with a damped spring

Use background color from SVG

Destroy bodies that fall off the physics world

Use textures

http://www.spiralgraphics.biz/packs/index.htm

Grappling wire could reattach when obstructed

Currently, the grappling wire passes through all objects once attached. It could reattach itself instead, or detach if it cannot attach to the obstructing object.

Grappling gun should ignore sensors