Animate instanced mesh

examples/Mesh/main.lua

@@ -1,8 +1,8 @@
 local fragmentShader = require("shader")
 
 local mesh1, mesh2
-local mesh4instance
-local mesh1program, mesh3program, mesh4program
+local mesh4Instance
+local mesh1Program, mesh3Program, mesh4Program
 local gridSize = 8
 
 -- Call this function with a string containing a glsl function preTransform()
@@ -12,7 +12,7 @@ local function makeShader(prefix)
 out vec3 lightDirection;
 out vec3 normalDirection;
 
-vec3 lightPosition = vec3(0, 10, 3);
+vec3 lightPosition = vec3(10, 10, 3);
 
 vec4 position(mat4 projection, mat4 transform, vec4 _vertex) {
   vec4 vertex = preTransform(_vertex);
@@ -29,20 +29,21 @@ vec4 position(mat4 projection, mat4 transform, vec4 _vertex) {
 end
 
 -- This "standard" program is the same as the standard light shader from the other examples-- it does nothing.
-local mesh1program = makeShader("vec4 preTransform(vec4 v) { return v; }")
+local mesh1Program = makeShader("vec4 preTransform(vec4 v) { return v; }")
 
 local rotate = 0
+local animate = 0
 
 function lovr.load()
   lovr.graphics.setCullingEnabled(true)
 
---  mesh1program()
+--  mesh1Program()
 
   mesh1 = lovr.graphics.newMesh({{ 'lovrPosition', 'float', 3 }, { 'lovrNormal', 'float', 3 }}, 3)
   mesh1:setVertices({{0,0,0, 0,0,1}, {1,0,0, 0,0,1}, {0,1,0, 0,0,1}}) -- A triangle
 
   mesh2 = lovr.graphics.newMesh({{ 'lovrPosition', 'float', 3 }, { 'lovrNormal', 'float', 3 }}, 24, 'triangles')
-  mesh2:setVertices({ -- Coordinates for mesh 2 (a cube)
+  local mesh2Vertices = { -- Coordinates for mesh 2 (a cube)
     {0,0,0, 0,0,-1}, -- Face front
     {0,1,0, 0,0,-1},
     {1,1,0, 0,0,-1},
@@ -72,7 +73,17 @@ function lovr.load()
     {1,0,0, 0,-1,0},
     {1,0,1, 0,-1,0},
     {0,0,1, 0,-1,0}
-  })
+  }
+
+  -- This cube covers the space 0..1, so it's centered at (0.5, 0.5, 0.5).
+  -- Edit the first three coordinates of each vertex to center it at (0,0,0):
+  for _, v in ipairs(mesh2Vertices) do
+    for i=1,3 do
+      v[i] = v[i] - 0.5
+    end
+  end
+
+  mesh2:setVertices(mesh2Vertices)
 
   mesh2:setVertexMap({ -- Indexes for mesh 2
     1,  2,  3,  1,  3,  4,  -- Face front
@@ -83,16 +94,18 @@ function lovr.load()
     21, 22, 23, 21, 23, 24, -- Face bottom
   })
 
-  mesh3program = makeShader([[
+  mesh3Program = makeShader([[
   uniform int gridSize;
+  uniform float animate;
   vec4 preTransform(vec4 v) {
     int x = gl_InstanceID % gridSize;
     int y = (gl_InstanceID / gridSize) % gridSize;
     int z = (gl_InstanceID / gridSize) / gridSize;
-    return v/vec4(2,2,2,1) + vec4(x,y,z,1);
+    float cubeSize = (sin(x + y + z + animate) + 1) / 2;
+    return v * vec4(cubeSize,cubeSize,cubeSize,1) + vec4(x,y,z,0) - vec4(gridSize, gridSize, gridSize, 0)/2;
   }
   ]])
-  mesh3program:send("gridSize", gridSize)
+  mesh3Program:send("gridSize", gridSize)
   --local vertexData = lovr.data.newVertexData(3, {{ 'position', 'float', 3 }, { 'normal', 'float', 3 }})
   --vertexData:setVertices({{0,0,0}, {0,1,0}, {1,0,0}})
 --  mesh:attachAttribute(instancingMesh, 'instancedPosition') -- NYI, attaches an attribute from a different mesh onto this mesh
@@ -100,11 +113,12 @@ function lovr.load()
 end
 
 function lovr.update(dt)
-  --rotate = rotate + dt/math.pi/2
+--  rotate = rotate + dt/math.pi/8
+  animate = animate + dt/math.pi*2
 end
 
 function lovr.draw(eye)
-  lovr.graphics.setShader(mesh1program)
+  lovr.graphics.setShader(mesh1Program)
   lovr.graphics.setColor(1,1,1,1)
   lovr.graphics.rotate(rotate, 0, 1, 0)
 
@@ -119,15 +133,16 @@ function lovr.draw(eye)
   mesh2:draw(0,0,0)
   lovr.graphics.pop()
 
-  lovr.graphics.setShader(mesh3program)
+  lovr.graphics.setShader(mesh3Program)
   lovr.graphics.push()
   lovr.graphics.rotate(2 * math.pi/2, 0, 1, 0)
-  lovr.graphics.translate(0, 0, -2)
-  lovr.graphics.scale(2/gridSize)
+  lovr.graphics.translate(0, 00, -2.5)
+  lovr.graphics.scale(1/gridSize)
+  mesh3Program:send("animate", animate)
   mesh2:drawInstanced(gridSize*gridSize*gridSize, 0,0,0)
   lovr.graphics.pop()
 
-  lovr.graphics.setShader(mesh1program)
+  lovr.graphics.setShader(mesh1Program)
   lovr.graphics.push()
   lovr.graphics.rotate(3 * math.pi/2, 0, 1, 0)
   lovr.graphics.translate(0, 0, -2)