// Copyright 2020 The Tint Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // vertex shader [[location(0)]] var<in> a_particlePos : vec2<f32>; [[location(1)]] var<in> a_particleVel : vec2<f32>; [[location(2)]] var<in> a_pos : vec2<f32>; [[builtin(position)]] var<out> gl_Position : vec4<f32>; [[stage(vertex)]] fn vert_main() -> void { var angle : f32 = -atan2(a_particleVel.x, a_particleVel.y); 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))); gl_Position = vec4<f32>(pos + a_particlePos, 0.0, 1.0); } // fragment shader [[location(0)]] var<out> fragColor : vec4<f32>; [[stage(fragment)]] fn frag_main() -> void { fragColor = vec4<f32>(1.0, 1.0, 1.0, 1.0); } // compute shader [[block]] struct Particle { [[offset(0)]] pos : vec2<f32>; [[offset(8)]] vel : vec2<f32>; }; [[block]] struct SimParams { [[offset(0)]] deltaT : f32; [[offset(4)]] rule1Distance : f32; [[offset(8)]] rule2Distance : f32; [[offset(12)]] rule3Distance : f32; [[offset(16)]] rule1Scale : f32; [[offset(20)]] rule2Scale : f32; [[offset(24)]] rule3Scale : f32; }; [[block]] struct Particles { [[offset(0)]] particles : [[stride(16)]] array<Particle, 5>; }; [[binding(0), group(0)]] var<uniform> params : [[access(read)]] SimParams; [[binding(1), group(0)]] var<storage> particlesA : [[access(read_write)]] Particles; [[binding(2), group(0)]] var<storage> particlesB : [[access(read_write)]] Particles; [[builtin(global_invocation_id)]] var<in> gl_GlobalInvocationID : vec3<u32>; // https://github.com/austinEng/Project6-Vulkan-Flocking/blob/master/data/shaders/computeparticles/particle.comp [[stage(compute)]] fn comp_main() -> void { var index : u32 = gl_GlobalInvocationID.x; if (index >= 5u) { return; } var vPos : vec2<f32> = particlesA.particles[index].pos; var vVel : vec2<f32> = particlesA.particles[index].vel; var cMass : vec2<f32> = vec2<f32>(0.0, 0.0); var cVel : vec2<f32> = vec2<f32>(0.0, 0.0); var colVel : vec2<f32> = vec2<f32>(0.0, 0.0); var cMassCount : i32 = 0; var cVelCount : i32 = 0; var pos : vec2<f32>; var vel : vec2<f32>; for(var i : u32 = 0u; i < 5u; i = i + 1) { if (i == index) { continue; } pos = particlesA.particles[i].pos.xy; vel = particlesA.particles[i].vel.xy; if (distance(pos, vPos) < params.rule1Distance) { cMass = cMass + pos; cMassCount = cMassCount + 1; } if (distance(pos, vPos) < params.rule2Distance) { colVel = colVel - (pos - vPos); } if (distance(pos, vPos) < params.rule3Distance) { cVel = cVel + vel; cVelCount = cVelCount + 1; } } if (cMassCount > 0) { cMass = (cMass / vec2<f32>(f32(cMassCount), f32(cMassCount))) - vPos; } if (cVelCount > 0) { cVel = cVel / vec2<f32>(f32(cVelCount), f32(cVelCount)); } vVel = vVel + (cMass * params.rule1Scale) + (colVel * params.rule2Scale) + (cVel * params.rule3Scale); // clamp velocity for a more pleasing simulation vVel = normalize(vVel) * clamp(length(vVel), 0.0, 0.1); // kinematic update vPos = vPos + (vVel * params.deltaT); // Wrap around boundary if (vPos.x < -1.0) { vPos.x = 1.0; } if (vPos.x > 1.0) { vPos.x = -1.0; } if (vPos.y < -1.0) { vPos.y = 1.0; } if (vPos.y > 1.0) { vPos.y = -1.0; } // Write back particlesB.particles[index].pos = vPos; particlesB.particles[index].vel = vVel; }