Comments added into the file

scene_screenshot_buffer.lua

@@ -5,64 +5,73 @@ hg = require("harfang")
 hg.InputInit()
 hg.WindowSystemInit()
 
-res_x, res_y = 1024, 1024
+local res_x, res_y, tex_size = 1024, 1024, 1024
 win = hg.RenderInit('Frame Buffer Screenshot', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
 
+--Link precompiled assets folder to the project
+hg.AddAssetsFolder("resources_compiled")
 
+--Create Pipeline
 pipeline = hg.CreateForwardPipeline()
 local res = hg.PipelineResources()
 
-hg.AddAssetsFolder("resources_compiled")
-
-local tex_size = 1024
-local picture = hg.Picture(tex_size, tex_size, hg.PF_RGBA32)
+--Create a 1024*1024 frame buffer to draw the scene to
 local frame_buffer = hg.CreateFrameBuffer(tex_size, tex_size, hg.TF_RGBA8, hg.TF_D24, 4, 'framebuffer')
 local tex_color = hg.GetColorTexture(frame_buffer)
+
+--Prepare screenshot requirements
 local tex_color_ref = res:AddTexture("tex_rb", tex_color)
 local tex_readback = hg.CreateTexture(tex_size, tex_size, "readback", hg.TF_ReadBack | hg.TF_BlitDestination, hg.TF_RGBA8)
+local picture = hg.Picture(tex_size, tex_size, hg.PF_RGBA32)
 
+--Load scene
 scene = hg.Scene()
 ret = hg.LoadSceneFromAssets("car_engine/engine.scn", scene, res, hg.GetForwardPipelineInfo())
 
-local state = "none"
-
-local frame = 0
-local view_id = 0
-
+--Create the plane model
 vtx_layout = hg.VertexLayoutPosFloatTexCoord0UInt8()
-
 plane_mdl = hg.CreatePlaneModel(vtx_layout, 1, 1, 1, 1)
 plane_ref = res:AddModel('plane', plane_mdl)
 
+--Prepare the plane shader program
 plane_prg = hg.LoadProgramFromAssets('shaders/texture')
 
+--Main Loop 
+local frame = 0
+local view_id = 0
+local state = "none"
 
 while not hg.ReadKeyboard():Key(hg.K_Escape) and hg.IsWindowOpen(win) do
 	dt = hg.TickClock()
 
+    --Change state to capture when user press Space and Capture is not already running
     if(hg.ReadKeyboard():Key(hg.K_Space) and state == "none") then
         state = "capture"
         frame_count_capture, view_id = hg.CaptureTexture(view_id, res, tex_color_ref, tex_readback, picture)
         print(frame_count_capture, frame) 
 
+    --Take screenshot if CaptureTexture is ready and user pressed space
     elseif(state == "capture" and frame_count_capture <= frame) then
         local png_filename = "screenshots/" .. ".png"
         hg.SavePNG(picture, png_filename)
-        state = "none"
+        state = "none" --Reset state to none to be able to screenshot again
     end
 
+    --Update Scene and render to the frameBuffer
 	scene:Update(dt)
 
     view_id = 0
 	view_id = hg.SubmitSceneToPipeline(view_id, scene, hg.IntRect(0, 0, res_x, res_y), true, pipeline, res, frame_buffer.handle)
 
+    --Draw a plabe using the texture the scene was rendered to
 	hg.SetViewPerspective(view_id, 0, 0, res_x, res_y, hg.TranslationMat4(hg.Vec3(0, 0, -1.8)))
 
 	val_uniforms = {hg.MakeUniformSetValue('color', hg.Vec4(1, 1, 1, 1))} 
 	tex_uniforms = {hg.MakeUniformSetTexture('s_tex', tex_color, 0)}
 
 	hg.DrawModel(view_id, plane_mdl, plane_prg, val_uniforms, tex_uniforms, hg.TransformationMat4(hg.Vec3(0, 0, 0), hg.Vec3(math.pi / 2, 0, math.pi)))
-
+
+    --
 	frame = hg.Frame()
 	hg.UpdateWindow(win)
 end