Witch of Git - lovr-particles/blob - main.lua

   1 local mat4 = lovr.math.mat4
   2
   3 local nParticles = 2 ^ 16
   4 local batchSize = 128
   5 local batches = nParticles / batchSize
   6
   7 local features
   8 local shaders = {}
   9 local blocks = {}
  10 local meshes = {}
  11 local compute = {}
  12
  13 function lovr.load()
  14     features = lovr.graphics.getFeatures()
  15
  16     shaders.particles = lovr.graphics.newShader("shaders/particles.vert", "shaders/particles.frag")
  17
  18     blocks.particles = lovr.graphics.newShaderBlock("compute", {
  19         particles = {"mat4", nParticles},
  20     }, { readable = true, writable = true })
  21     shaders.particles:sendBlock('particleData', blocks.particles)
  22     shaders.particles:send("batchSize", batchSize)
  23
  24     meshes.particle = makeParticleMesh(batchSize)
  25
  26     compute.particles = lovr.graphics.newComputeShader("shaders/particles.comp")
  27     compute.particles:sendBlock('particleData', blocks.particles)
  28     compute.particles:send("dt", 0.0)
  29
  30     local initial = initialParticleData(nParticles, range(-2, 2), range(0, 4), range(-2, 2), range(0.005, 0.01))
  31     blocks.particles:send("particles", initial)
  32 end
  33
  34 function lovr.draw()
  35     lovr.graphics.clear()
  36     local x, y, z = lovr.headset.getPose("head")
  37     -- lovr.graphics.compute(compute.particles, batches)
  38     shaders.particles:send("headPos", {x, y, z})
  39
  40     lovr.graphics.setColor(0.6, 0.1, 0)
  41     lovr.graphics.setShader(nil)
  42     for _, hand in ipairs(lovr.headset.getHands()) do
  43         local x, y, z, a, ax, ay, az = lovr.headset.getPose(hand)
  44         lovr.graphics.cube("fill", x, y, z, 0.1, a, ax, ay, az)
  45     end
  46
  47     withDepthTest("lequal", false, function()
  48         lovr.graphics.setColor(1, 1, 1)
  49         lovr.graphics.setShader(shaders.particles)
  50         meshes.particle:draw(mat4(), batches)
  51     end)
  52 end
  53
  54 function makeParticleMesh(size)
  55     local format = { {'vertPosition', 'float', 2}, }
  56     local verts = {}
  57     local vertMap = {}
  58     local insert = table.insert
  59     for chunk = 1, size do
  60         insert(verts, { 1,  1})
  61         insert(verts, { 1, -1})
  62         insert(verts, {-1, -1})
  63         insert(verts, {-1,  1})
  64         local base = 4 * (chunk - 1)
  65         insert(vertMap, 3 + base)
  66         insert(vertMap, 2 + base)
  67         insert(vertMap, 1 + base)
  68         insert(vertMap, 4 + base)
  69         insert(vertMap, 3 + base)
  70         insert(vertMap, 1 + base)
  71     end
  72     local mesh = lovr.graphics.newMesh(format, verts, "triangles", "static")
  73     mesh:setVertexMap(vertMap)
  74     return mesh
  75 end
  76
  77 function range(min, max)
  78     local scale = max - min
  79     return function()
  80         return min + lovr.math.random() * scale
  81     end
  82 end
  83
  84 function initialParticleData(size, xRange, yRange, zRange, sRange)
  85     local particles = {}
  86     local insert = table.insert
  87     for i = 1, size do
  88         insert(particles, {
  89             xRange(), yRange(), zRange(), sRange(),
  90             xRange(), yRange(), zRange(), 1,
  91             0, 0, 0, 0,
  92             0, 0, 0, 0,
  93         })
  94     end
  95     return particles
  96 end
  97
  98 function withDepthTest(compareMode, write, callback)
  99     local oldComp, oldWrite = lovr.graphics.getDepthTest()
 100     lovr.graphics.setDepthTest(compareMode, write)
 101     callback()
 102     lovr.graphics.setDepthTest(oldComp, oldWrite)
 103 end