From f7e0383457f3f7cdef185dbeb4b90647ce65fcd1 Mon Sep 17 00:00:00 2001
From: Astrofra <astrofra@gmail.com>
Date: Fri, 31 Dec 2021 14:18:14 +0100
Subject: [PATCH] Tutorials update for HARFANG v3.1.1.

---
 README.md           |  4 ++--
 physics_impulse.lua | 35 ++++++++++++++++++++++++++---------
 physics_kapla.lua   |  2 +-
 physics_kapla.py    |  2 +-
 scene_aaa.lua       |  1 +
 scene_aaa.py        |  1 +
 6 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 3fac490..b087596 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
-# HARFANG® 3.1.0 Tutorials
+# HARFANG® Tutorials
 
-These **tutorials** demonstrate the usage of the HARFANG 3.1.0 API in **Python** and **Lua**.
+These **tutorials** demonstrate the usage of the HARFANG API in **Python** and **Lua**.
 
 To run the tutorials:
 
diff --git a/physics_impulse.lua b/physics_impulse.lua
index 7ff062e..69ef2b0 100644
--- a/physics_impulse.lua
+++ b/physics_impulse.lua
@@ -6,7 +6,7 @@ hg.InputInit()
 hg.WindowSystemInit()
 
 res_x, res_y = 1280, 720
-win = hg.RenderInit('Harfang - Physics Impulse', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
+win = hg.RenderInit('Harfang - Physics Force/Impulse (Press space to alternate)', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
 
 pipeline = hg.CreateForwardPipeline()
 res = hg.PipelineResources()
@@ -45,22 +45,39 @@ physics_step = hg.time_from_sec_f(1 / 60)
 -- main loop
 keyboard = hg.Keyboard()
 
+use_force = true
+
 while not keyboard:Down(hg.K_Escape) do
 	keyboard:Update()
 
 	dt = hg.TickClock()
 
-	if keyboard:Pressed(hg.K_I) then
-		physics:NodeWake(cube_node)
-		world_pos = hg.GetT(cube_node:GetTransform():GetWorld())
-		physics:NodeAddImpulse(cube_node, hg.Vec3(0, 8, 0), world_pos)
+	if keyboard:Pressed(hg.K_Space) then
+		use_force = not use_force
 	end
-	if keyboard:Pressed(hg.K_F) then
-		physics:NodeWake(cube_node)
-		world_pos = hg.GetT(cube_node:GetTransform():GetWorld())
-		physics:NodeAddForce(cube_node, hg.Vec3(0, 8, 0), world_pos)
+
+	world_pos = hg.GetT(cube_node:GetTransform():GetWorld())
+	dist_to_ground = world_pos.y - 0.5
+
+	if dist_to_ground < 1.0 then
+		k = -(dist_to_ground - 1.0)
+
+		if use_force then
+			F = hg.Vec3(0, 1, 0) * k * 80  -- apply a force inversely proportional to the distance to the ground
+			physics:NodeAddForce(cube_node, F, world_pos)
+		else
+			stiffness = 10
+
+			cur_velocity = physics:NodeGetLinearVelocity(cube_node)
+			tgt_velocity = hg.Vec3(0, 1, 0) * k * stiffness  -- compute a velocity that brings us to 1 meter above the ground
+
+			I = tgt_velocity - cur_velocity  -- an impulse is an instantaneous change in velocity
+			physics:NodeAddImpulse(cube_node, I, world_pos)
+		end
 	end
 
+	physics:NodeWake(cube_node)
+
 	hg.SceneUpdateSystems(scene, clocks, dt, physics, physics_step, 3)
 	hg.SubmitSceneToPipeline(0, scene, hg.IntRect(0, 0, res_x, res_y), true, pipeline, res)
 
diff --git a/physics_kapla.lua b/physics_kapla.lua
index faf20ec..c7e1de2 100644
--- a/physics_kapla.lua
+++ b/physics_kapla.lua
@@ -6,7 +6,7 @@ hg.InputInit()
 hg.WindowSystemInit()
 
 res_x, res_y = 1280, 720
-win = hg.RenderInit('Harfang - Kapla', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
+win = hg.RenderInit('Harfang - Kapla - Press SPACEBAR', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
 
 hg.AddAssetsFolder('resources_compiled')
 
diff --git a/physics_kapla.py b/physics_kapla.py
index a59e6ce..2d22cb9 100644
--- a/physics_kapla.py
+++ b/physics_kapla.py
@@ -7,7 +7,7 @@
 hg.WindowSystemInit()
 
 res_x, res_y = 1280, 720
-win = hg.RenderInit('Harfang - Kapla', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
+win = hg.RenderInit('Harfang - Kapla - Press SPACEBAR', res_x, res_y, hg.RF_VSync | hg.RF_MSAA4X)
 
 hg.AddAssetsFolder('resources_compiled')
 
diff --git a/scene_aaa.lua b/scene_aaa.lua
index 7bd10c5..93c8745 100644
--- a/scene_aaa.lua
+++ b/scene_aaa.lua
@@ -23,6 +23,7 @@ hg.LoadSceneFromAssets("car_engine/engine.scn", scene, res, hg.GetForwardPipelin
 -- AAA pipeline
 pipeline_aaa_config = hg.ForwardPipelineAAAConfig()
 pipeline_aaa = hg.CreateForwardPipelineAAAFromAssets("core", pipeline_aaa_config, hg.BR_Equal, hg.BR_Equal)
+pipeline_aaa_config.sample_count = 1
 
 -- main loop
 frame = 0
diff --git a/scene_aaa.py b/scene_aaa.py
index a45467a..192713f 100644
--- a/scene_aaa.py
+++ b/scene_aaa.py
@@ -22,6 +22,7 @@
 # AAA pipeline
 pipeline_aaa_config = hg.ForwardPipelineAAAConfig()
 pipeline_aaa = hg.CreateForwardPipelineAAAFromAssets("core", pipeline_aaa_config, hg.BR_Equal, hg.BR_Equal)
+pipeline_aaa_config.sample_count = 1
 
 # main loop
 frame = 0