finite projection matrix, rotation matrix

main.lua

@@ -6,7 +6,7 @@ local testMesh = love.graphics.newMesh(
   },
   {--vertices
     { 0, 0, 0, 1,
-      0, 0, 0 },
+      1, 1, 1 },
     { 1, 0, 0, 1,
       1, 0, 0 },
     { 0, 1, 0, 1,
@@ -39,36 +39,105 @@ local testQuad = love.graphics.newMesh(
 )
 
 local testShader = [[
+  varying float d;
 #ifdef VERTEX
   uniform mat4 mdl;
   uniform mat4 view;
   uniform mat4 proj;
   vec4 position( mat4 _, vec4 pos ){
-    return proj*view*mdl*pos;
+    vec4 cam = view*mdl*pos;
+    d = cam.z;
+    return proj * cam;
   }
 #endif
 #ifdef PIXEL
   vec4 effect( vec4 color, Image tex, vec2 texuv, vec2 scruv) {
-    return color * vec4( 1., 1., 1., 0.5 );
+    return color * vec4( 1.0, 1.0, 1.0, 1.0 ) ;
   }
 #endif
 ]]
 testShader = love.graphics.newShader( testShader, testShader )
 
+--TODO: column major
+local function prod( A, B )
+  local C = {}
+  for j = 1,4 do C[j] = {0, 0, 0, 0} end
+  for j = 1, 4 do
+    for i = 1, 4 do
+      C[j][i] =
+      A[1][i] * B[j][1] +
+      A[2][i] * B[j][2] +
+      A[3][i] * B[j][3] +
+      A[4][i] * B[j][4]
+    end
+  end
+  return C
+end
+
+
+local function roll( t )
+  local c, s = math.cos(t), math.sin(t)
+  return {
+    {c, 0, s, 0},
+    {0, 1,  0, 0},
+    {-s, 0, c, 0},
+    {0, 0,  0, 1},
+  }
+end
+
+
+local function trans( x, y, z )
+  return {
+    {1, 0, 0, 0},
+    {0, 1, 0, 0},
+    {0, 0, 1, 0},
+    {x, y, z, 1},
+  }
+end
+
+local function scale( x, y, z )
+  return {
+    {x, 0, 0, 0},
+    {0, y, 0, 0},
+    {0, 0, z, 0},
+    {0, 0, 0, 1},
+  }
+end
+
+local function id()
+  return {
+    {1, 0, 0, 0},
+    {0, 1, 0, 0},
+    {0, 0, 1, 0},
+    {0, 0, 0, 1},
+  }
+end
+
+--tait-bryan yaw pitch roll
+local function rotate( a, b, g )
+  local c, s = math.cos, math.sin
+  local ca, sa, cb, sb, cg, sg = c(a), s(a), c(b), s(b), c(g), s(g)
+  return {
+    {           ca*cb,            sa*cb,   -sb, 0},
+    {ca*sb*sg - sa*cg, sa*sb*sg + ca*cg, cb*sg, 0},
+    {ca*sb*cg + sa*sg, sa*sb*cg - ca*sg, cb*cg, 0},
+    {    0,                0,                0, 1},
+  }
+end
+
 --fov in degrees, aspect w/h, near far
-local function getProjectionMatrix(n, f)
+local function getProjectionMatrix(n, f, fov)
   local r = love.graphics.getWidth() / 2
   local t = love.graphics.getHeight() / 2
-  return --[[{
-    {n/r, 0, 0, 0},
-    {0, n/t, 0, 0},
-    {0,   0,       -(f+n)/(f-n),   -2 * f * n / (f-n) },
-    {0, 0,    -1,      0},
-  }]]
-  { {1, 0, 0,      0},
-    {0,-1, 0,      0},
-    {0, 0,  -1, -2*n},
-    {0, 0,  -1,    0},
+  local aspect = r/t
+  local tan = math.tan( fov / 2 )
+  return 
+  --infinite z
+  --TODO: get finite
+  { {1.0 / tan, 0,   0,    0},
+    {0, -1.0 / tan,  0,    0},
+    {0, 0,  ( f + n ) / (n-f),  -1 },
+    {0, 0,  -2 * f * n / (f - n),    0},
   }
 end
 
@@ -80,23 +149,10 @@ local function getViewMatrix()
     {0, 0, 0, 1},
   }
 end
-
-local testID = {
-    {1, 0, 0, 0},
-    {0, 1, 0, 0},
-    {0, 0, 1, 0},
-    {0, 0, 0, 1},
-  }
   
-  
-local testModelMatrix = {
-    {1,           0,         0,  0},
-    {0,           1,         0,  0},
-    {0,           0,         1, -2}, 
-    {0,           0,         0,  1},
-  }
+local testModelMatrix
 local testViewMatrix = getViewMatrix()
-local testProjection = getProjectionMatrix( 0.2, 10 )
+local testProjection = getProjectionMatrix( 0.1, 10, math.rad( 30 ) )
 local time = 0
 
 local testDSCanvas = love.graphics.newCanvas(
@@ -118,29 +174,36 @@ function love.draw()
   love.graphics.clear()
   love.graphics.setDepthMode( "less", true )
   love.graphics.setShader( testShader )
-  testShader:send( "mdl",  "row", testModelMatrix )
-  testShader:send( "proj", "row", testProjection )
-  testShader:send( "view", "row", testViewMatrix )
+  testShader:send( "mdl",  "column", testModelMatrix )
+  testShader:send( "proj", "column", testProjection )
+  testShader:send( "view", "column", testViewMatrix )
   love.graphics.draw( testMesh )
   
-  testShader:send( "mdl", "column", testID )
-  love.graphics.draw( testQuad )
+  testShader:send( "mdl", "column", id() )
+  --love.graphics.draw( testQuad )
   
   love.graphics.setShader()
-  love.graphics.draw( testQuad )
   love.graphics.setColor(1,1,1, 0.5 )
- -- love.graphics.rectangle( "fill", 0, 0, love.graphics.getDimensions() )
+  --love.graphics.rectangle( "fill", 0, 0, love.graphics.getDimensions() )
   love.graphics.setCanvas()
   love.graphics.setDepthMode( "always", true )
   love.graphics.pop()
   love.graphics.draw( testCanvas )
-  love.graphics.print( string.format( "%05.2f\t:TIME\n%05.2f\t:ANGLE", time, (180 / math.pi) * time / 15 ) )
+  love.graphics.print( string.format( "%05.2f\t:TIME\n%05.2f\t:ANGLE", time,  time ))
   --[[love.graphics.setShader()
   love.graphics.setColor( 1,1,1,1 )
   love.graphics.circle( "fill", time, time/2, 5 )]]
 end
 
 function love.update( dt )
-  time = time + 10 * dt
-  testModelMatrix[3][4] = -2.0 - math.sin( time / 5 )
+  time = time + dt
+  testModelMatrix = prod(
+    trans( 0, 0, -4 + math.sin( time )), 
+    roll( time )
+  )
+  testModelMatrix = prod(
+    testModelMatrix,
+    rotate( time, time, time )
+    
+  )
 end