Ben Clayton | d123267 | 2021-05-18 09:24:18 +0000 | [diff] [blame] | 1 | [[stage(vertex)]] |
| 2 | fn vert_main([[location(0)]] a_particlePos : vec2<f32>, [[location(1)]] a_particleVel : vec2<f32>, [[location(2)]] a_pos : vec2<f32>) -> [[builtin(position)]] vec4<f32> { |
| 3 | var angle : f32 = -(atan2(a_particleVel.x, a_particleVel.y)); |
| 4 | var pos : vec2<f32> = vec2<f32>(((a_pos.x * cos(angle)) - (a_pos.y * sin(angle))), ((a_pos.x * sin(angle)) + (a_pos.y * cos(angle)))); |
| 5 | return vec4<f32>((pos + a_particlePos), 0.0, 1.0); |
| 6 | } |
| 7 | |
| 8 | [[stage(fragment)]] |
| 9 | fn frag_main() -> [[location(0)]] vec4<f32> { |
| 10 | return vec4<f32>(1.0, 1.0, 1.0, 1.0); |
| 11 | } |
| 12 | |
| 13 | struct Particle { |
| 14 | pos : vec2<f32>; |
| 15 | vel : vec2<f32>; |
| 16 | }; |
| 17 | |
| 18 | [[block]] |
| 19 | struct SimParams { |
| 20 | deltaT : f32; |
| 21 | rule1Distance : f32; |
| 22 | rule2Distance : f32; |
| 23 | rule3Distance : f32; |
| 24 | rule1Scale : f32; |
| 25 | rule2Scale : f32; |
| 26 | rule3Scale : f32; |
| 27 | }; |
| 28 | |
| 29 | [[block]] |
| 30 | struct Particles { |
| 31 | particles : array<Particle, 5>; |
| 32 | }; |
| 33 | |
| 34 | [[binding(0), group(0)]] var<uniform> params : SimParams; |
| 35 | |
Ben Clayton | 93e8f52 | 2021-06-04 20:41:47 +0000 | [diff] [blame] | 36 | [[binding(1), group(0)]] var<storage, read_write> particlesA : Particles; |
Ben Clayton | d123267 | 2021-05-18 09:24:18 +0000 | [diff] [blame] | 37 | |
Ben Clayton | 93e8f52 | 2021-06-04 20:41:47 +0000 | [diff] [blame] | 38 | [[binding(2), group(0)]] var<storage, read_write> particlesB : Particles; |
Ben Clayton | d123267 | 2021-05-18 09:24:18 +0000 | [diff] [blame] | 39 | |
Sarah | e6cb51e | 2021-06-29 18:39:44 +0000 | [diff] [blame] | 40 | [[stage(compute), workgroup_size(1)]] |
Ben Clayton | d123267 | 2021-05-18 09:24:18 +0000 | [diff] [blame] | 41 | fn comp_main([[builtin(global_invocation_id)]] gl_GlobalInvocationID : vec3<u32>) { |
| 42 | var index : u32 = gl_GlobalInvocationID.x; |
| 43 | if ((index >= 5u)) { |
| 44 | return; |
| 45 | } |
| 46 | var vPos : vec2<f32> = particlesA.particles[index].pos; |
| 47 | var vVel : vec2<f32> = particlesA.particles[index].vel; |
| 48 | var cMass : vec2<f32> = vec2<f32>(0.0, 0.0); |
| 49 | var cVel : vec2<f32> = vec2<f32>(0.0, 0.0); |
| 50 | var colVel : vec2<f32> = vec2<f32>(0.0, 0.0); |
| 51 | var cMassCount : i32 = 0; |
| 52 | var cVelCount : i32 = 0; |
| 53 | var pos : vec2<f32>; |
| 54 | var vel : vec2<f32>; |
Ben Clayton | 1b03f0a | 2021-07-08 21:23:33 +0000 | [diff] [blame] | 55 | for(var i : u32 = 0u; (i < 5u); i = (i + 1u)) { |
| 56 | if ((i == index)) { |
| 57 | continue; |
| 58 | } |
| 59 | pos = particlesA.particles[i].pos.xy; |
| 60 | vel = particlesA.particles[i].vel.xy; |
| 61 | if ((distance(pos, vPos) < params.rule1Distance)) { |
| 62 | cMass = (cMass + pos); |
| 63 | cMassCount = (cMassCount + 1); |
| 64 | } |
| 65 | if ((distance(pos, vPos) < params.rule2Distance)) { |
| 66 | colVel = (colVel - (pos - vPos)); |
| 67 | } |
| 68 | if ((distance(pos, vPos) < params.rule3Distance)) { |
| 69 | cVel = (cVel + vel); |
| 70 | cVelCount = (cVelCount + 1); |
Ben Clayton | d123267 | 2021-05-18 09:24:18 +0000 | [diff] [blame] | 71 | } |
| 72 | } |
| 73 | if ((cMassCount > 0)) { |
| 74 | cMass = ((cMass / vec2<f32>(f32(cMassCount), f32(cMassCount))) - vPos); |
| 75 | } |
| 76 | if ((cVelCount > 0)) { |
| 77 | cVel = (cVel / vec2<f32>(f32(cVelCount), f32(cVelCount))); |
| 78 | } |
| 79 | vVel = (((vVel + (cMass * params.rule1Scale)) + (colVel * params.rule2Scale)) + (cVel * params.rule3Scale)); |
| 80 | vVel = (normalize(vVel) * clamp(length(vVel), 0.0, 0.100000001)); |
| 81 | vPos = (vPos + (vVel * params.deltaT)); |
| 82 | if ((vPos.x < -1.0)) { |
| 83 | vPos.x = 1.0; |
| 84 | } |
| 85 | if ((vPos.x > 1.0)) { |
| 86 | vPos.x = -1.0; |
| 87 | } |
| 88 | if ((vPos.y < -1.0)) { |
| 89 | vPos.y = 1.0; |
| 90 | } |
| 91 | if ((vPos.y > 1.0)) { |
| 92 | vPos.y = -1.0; |
| 93 | } |
| 94 | particlesB.particles[index].pos = vPos; |
| 95 | particlesB.particles[index].vel = vVel; |
| 96 | } |