From 9bcab00b4d7765fc21055b1151091c929e36c939 Mon Sep 17 00:00:00 2001
From: wan-may <info@wan-may.art>
Date: Sun, 9 Mar 2025 21:16:01 -0300
Subject: [PATCH] day one progress: render two models

---
 main.lua | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 main.lua

diff --git a/main.lua b/main.lua
new file mode 100644
index 0000000..4b834fd
--- /dev/null
+++ b/main.lua
@@ -0,0 +1,146 @@
+local love = assert( love )
+local testMesh = love.graphics.newMesh(
+  {--attributes
+    {"VertexPosition", "float", 4},
+    {"VertexColor", "float", 3}
+  },
+  {--vertices
+    { 0, 0, 0, 1,
+      0, 0, 0 },
+    { 1, 0, 0, 1,
+      1, 0, 0 },
+    { 0, 1, 0, 1,
+      0, 1, 0 },
+    { 0, 0, 1, 1,
+      0, 0, 1 },
+  },
+  "strip",
+  "static"
+)
+testMesh:setVertexMap{ 1,2,3,4,1,2 }
+
+local testQuad = love.graphics.newMesh(
+  {--attributes
+    {"VertexPosition", "float", 4},
+    {"VertexColor", "float", 3}
+  },
+  {--vertices
+    { -1, -1,- 2, 1,
+      1, 1, 1 },
+    { 1, -1,- 2, 1,
+      1, 0, 0 },
+    { 1, 1,- 2, 1,
+      0, 0, 1 },
+    { -1, 1,- 2, 1,
+      0, 1, 0 },
+  },
+  "fan",
+  "static"
+)
+
+local testShader = [[
+#ifdef VERTEX
+  uniform mat4 mdl;
+  uniform mat4 view;
+  uniform mat4 proj;
+  vec4 position( mat4 _, vec4 pos ){
+    return proj*view*mdl*pos;
+  }
+#endif
+#ifdef PIXEL
+  vec4 effect( vec4 color, Image tex, vec2 texuv, vec2 scruv) {
+    return color * vec4( 1., 1., 1., 0.5 );
+  }
+#endif
+]]
+testShader = love.graphics.newShader( testShader, testShader )
+
+--fov in degrees, aspect w/h, near far
+local function getProjectionMatrix(n, f)
+  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},
+  }
+end
+
+local function getViewMatrix()
+  return {
+    {1, 0, 0, 0},
+    {0, 1, 0, 0},
+    {0, 0, 1, 0},
+    {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 testViewMatrix = getViewMatrix()
+local testProjection = getProjectionMatrix( 0.2, 10 )
+local time = 0
+
+local testDSCanvas = love.graphics.newCanvas(
+  love.graphics.getWidth(),
+  love.graphics.getHeight(),
+  { readable = true,
+    format = "depth24" })
+
+local testCanvas = love.graphics.newCanvas()
+
+--row major
+--4th column [:][4] translates
+--diagonal [i][i], i < 4 scales
+--rotations in [1:3][1:3]
+function love.draw()
+  love.graphics.setColor( 1, 1 ,1, 1 )
+  love.graphics.push( "all" )
+  love.graphics.setCanvas( { testCanvas, depthstencil = testDSCanvas } )
+  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 )
+  love.graphics.draw( testMesh )
+  
+  testShader:send( "mdl", "column", testID )
+  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.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.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 )
+end
\ No newline at end of file