OpenEuphoria

1. Jolt Physics Wrapper

• Posted by Icy_Viking Jun 15, 2023
• 962 views

Hello,

I've recently written a wrapper of the Jolt Physics Library. However when trying to make a example program, nothing shows up.

https://github.com/amerkoleci/JoltPhysicsSharp/blob/main/src/joltc/joltc.h - This is the Wrapper code that I made the wrapper from.

https://github.com/michal-z/zig-gamedev/blob/main/libs/zphysics/libs/JoltC/JoltPhysicsC_Tests.c - I tried converting the HelloWorld test to Eu code, which is the code below.

Notice the difference from JPH and JPC. I used the CSharp C port to write the wrapper. As I couldn't figure out how to make the Zig C port into a DLL. So that's why the wrapper uses JPH as its name calling convention for exporting.

https://katfile.com/rdhsy0f8i5c9/Jolt.zip.html - Includes the wrapper, attempted example and JoltC DLL.

I'm not sure if I'm overlooking something that is simple, or I screwed up somewhere else. A fresh pair of eyes may help.

https://github.com/jrouwe/JoltPhysics - The official CPP port of Jolt Physics.

--Hello World Example Jolt Physics 
 
include std/ffi.e 
include std/machine.e 
 
include jolt.e 
 
atom j = JPH_Init() 
 
if j = -1 then 
	puts(1,"Failed to init Jolt Physics!\n") 
	abort(0) 
end if 
 
atom sys = JPH_PhysicsSystem_Create() 
 
atom talloc = JPH_TempAllocator_Create(10 * 1024 * 1024) 
atom job_sys = JPH_JobSystemThreadPool_Create(2048,8,-1) 
 
constant max_bodies = 1024 
constant num_body_mutexes = 0 
constant max_body_pairs = 1024 
constant max_contact_constraints = 1024 
 
atom broad_phase_layer_interface = JPH_BroadPhaseLayerInterface_Create() 
 
atom broad_phase_layer_filter = JPH_ObjectVsBroadPhaseLayerFilter_Create() 
 
atom pair_filter = JPH_ObjectLayerPairFilter_Create() 
 
JPH_PhysicsSystem_Init(sys,max_bodies,num_body_mutexes,max_body_pairs,max_contact_constraints, 
					   broad_phase_layer_interface,broad_phase_layer_filter,pair_filter) 
					    
atom body_act_list = JPH_BodyActivationListener_Create() 
 
JPH_PhysicsSystem_SetBodyActivationListener(sys,body_act_list) 
 
atom contact_list = JPH_ContactListener_Create() 
 
JPH_PhysicsSystem_SetContactListener(sys,contact_list) 
 
atom body_interface = JPH_PhysicsSystem_GetBodyInterface(sys) 
 
atom ground_vec3 = allocate_struct(JPH_Vec3,{100.0,1.0,100.0}) 
atom ground_quat = allocate_struct(JPH_Quat,{0.0,0.0,0.0,1.0}) 
 
atom ground_shape_settings = JPH_BoxShapeSettings_Create(ground_vec3,NULL) 
atom ground_shape = JPH_BoxShape_Create(ground_shape_settings,NULL) 
 
atom ground_settings = JPH_BodyCreationSettings_Create() 
 
atom ground_set = JPH_BodyCreationSettings_Create2(ground_settings, 
												  ground_vec3,ground_quat,JPH_MOTION_TYPE_STATIC, 
												  0) 
												   
atom ground_set2 = JPH_BodyCreationSettings_Create3(ground_shape,ground_vec3,ground_quat,JPH_MOTION_TYPE_STATIC,0) 
 
atom ground_body = JPH_BodyInterface_CreateBody(body_interface,ground_settings) 
 
atom ground_id = JPH_BodyInterface_AssignBodyID2(body_interface,ground_body,1) 
 
JPH_BodyInterface_AddBody(body_interface,ground_body,JPH_ACTIVATION_MODE_DONT_ACTIVATE) 
 
atom sphere_vec3 = allocate_struct(JPH_Vec3,{0.0,2.0,0.0}) 
atom sphere_quat = allocate_struct(JPH_Quat,{0.0,0.0,0.0,1.0}) 
 
atom sphere_rad = 0.5 
atom sphere_shape_settings = JPH_SphereShapeSettings_Create(sphere_rad) 
atom sphere_shape = JPH_SphereShape_Create(sphere_rad) 
 
atom sphere_settings = JPH_BodyCreationSettings_Create() 
 
atom sphere_set = JPH_BodyCreationSettings_Create2(sphere_settings,sphere_vec3,sphere_quat,JPH_MOTION_TYPE_DYNAMIC,0) 
atom sphere_set2 = JPH_BodyCreationSettings_Create3(sphere_shape,sphere_vec3,sphere_quat,JPH_MOTION_TYPE_DYNAMIC,0) 
 
atom sphere_id = JPH_BodyInterface_CreateAndAddBody(body_interface,sphere_shape_settings,JPH_ACTIVATION_MODE_ACTIVATE) 
 
atom sphere_vel = allocate_struct(JPH_Vec3,{0.0,-5.0,0.0}) 
JPH_BodyInterface_SetLinearVelocity(body_interface,sphere_id,sphere_vel) 
 
JPH_PhysicsSystem_OptimizeBroadPhase(sys) 
 
atom step = 0 
 
atom pos = allocate_struct(JPH_Vec3,{0,0,0}) 
sequence vel = {3} 
 
constant delta_time = 1.0 / 60.0 
constant collision_steps = 1 
constant integration_sub_steps = 1 
	 
while JPH_BodyInterface_IsActive(body_interface,sphere_id) do 
	step = step + 1 
	 
	JPH_BodyInterface_GetCenterOfMassPosition(body_interface,sphere_id,pos) 
	 
	JPH_BodyInterface_GetLinearVelocity(body_interface,sphere_id,vel) 
	 
	JPH_PhysicsUpdateError up = JPH_PhysicsSystem_Update(sys,delta_time,collision_steps,integration_sub_steps,talloc,job_sys) 
	 
	if up != JPH_PHYSICS_UPDATE_ERROR_NONE then 
		puts(1,"No Physics!\n") --Not sure if this if statement is needed 
	end if 
	 
	printf(1,"Step: %d\n Position %f, %f, %f,\n %f,%f,%f",{step,pos[1],pos[2],pos[3],vel[1],vel[2],vel[3]}) --nothing shows up on the command line.  
end while 
 
JPH_BodyInterface_RemoveBody(body_interface,sphere_id) 
JPH_BodyInterface_DestroyBody(body_interface,sphere_id) 
JPH_BodyInterface_RemoveBody(body_interface,ground_id) 
JPH_BodyInterface_DestroyBody(body_interface,ground_id) 
JPH_Shape_Destroy(ground_shape) 
JPH_BodyCreationSettings_Destroy(ground_settings) 
JPH_ContactListener_Destroy(contact_list) 
JPH_BodyActivationListener_Destroy(body_act_list) 
JPH_ObjectLayerPairFilter_Destroy(pair_filter) 
JPH_ObjectVsBroadPhaseLayerFilter_Destroy(broad_phase_layer_filter) 
JPH_BroadPhaseLayerInterface_Destroy(broad_phase_layer_interface) 
JPH_JobSystemThreadPool_Destroy(job_sys) 
JPH_TempAllocator_Destroy(talloc) 
JPH_PhysicsSystem_Destroy(sys) 
JPH_Shutdown() 

3. Re: Jolt Physics Wrapper

• Posted by Icy_Viking Jun 26, 2023
• 783 views

I tried that after installing Zig and still couldn't get it to work. Apparently there's a bug with it, currently.

see - https://stackoverflow.com/questions/76024979/creating-a-32-bit-windows-dll-using-zig-without-the-c-runtime-and-removing-unnec

5. Re: Jolt Physics Wrapper

• Posted by Icy_Viking Jul 01, 2023
• 764 views

You son of a gun, Greg! It worked! I was able to compile JoltC in a DLL using your tips. I was having a lot of trouble trying to compile/build it using Zig. Note that JoltC is still a work in progress, but I can try and make a wrapper and see if its feasible with Euphoria. I also notice that Bullet physics, well the C port of Bullet physics is also part of the zig game dev package. I'm working on upgrading my SFML wrapper, after that I'll start work on JoltC wrapper and see if its hopefully feasible. Thanks for helping!