From 983ca485f5c41838917f457bbd0da1650620aa71 Mon Sep 17 00:00:00 2001
From: viktorljung <vilb12@student.bth.se>
Date: Thu, 3 Dec 2015 14:50:14 +0100
Subject: [PATCH] Picking now returning world position

---
 include/Engine/Rendering/Camera.h   | 10 ++++---
 include/Engine/Rendering/Renderer.h |  5 ++++
 src/Engine/Rendering/Renderer.cpp   | 46 +++++++++++++++++++++++++----
 3 files changed, 51 insertions(+), 10 deletions(-)

diff --git a/include/Engine/Rendering/Camera.h b/include/Engine/Rendering/Camera.h
index 6a1acdd8..660dfd49 100644
--- a/include/Engine/Rendering/Camera.h
+++ b/include/Engine/Rendering/Camera.h
@@ -46,10 +46,7 @@ public:
 	float FarClip() const { return m_FarClip; }
 	void SetFarClip(float val);
 
-	float m_AspectRatio;
-	float m_FOV;
-	float m_NearClip;
-	float m_FarClip;
+	
 
 private:
 	void UpdateViewMatrix();
@@ -60,6 +57,11 @@ private:
 
 	glm::mat4 m_ProjectionMatrix;
 	glm::mat4 m_ViewMatrix;
+
+    float m_AspectRatio;
+    float m_FOV;
+    float m_NearClip;
+    float m_FarClip;
 };
 
 #endif
\ No newline at end of file
diff --git a/include/Engine/Rendering/Renderer.h b/include/Engine/Rendering/Renderer.h
index f9a51d4e..6fb0b10f 100644
--- a/include/Engine/Rendering/Renderer.h
+++ b/include/Engine/Rendering/Renderer.h
@@ -52,6 +52,11 @@ private:
     void DrawScreenQuad(GLuint textureToDraw);
     glm::vec3 GetClickedPixelData(float x, float y);
     void DrawScene(RenderQueueCollection& rq);
+
+    //--------------------Utility functions----------------//
+    glm::vec3 ScreenCoordsToWorldPos(glm::vec2 screenCoord, float depth);
+    //EntityID ScreenCoordsToEntityID(glm::vec2 screenCoord, float depth);
+
 	//--------------------ShaderPrograms-------------------//
 	ShaderProgram m_BasicForwardProgram;
     ShaderProgram m_PickingProgram;
diff --git a/src/Engine/Rendering/Renderer.cpp b/src/Engine/Rendering/Renderer.cpp
index ef18d631..bbaab41e 100644
--- a/src/Engine/Rendering/Renderer.cpp
+++ b/src/Engine/Rendering/Renderer.cpp
@@ -80,12 +80,14 @@ void Renderer::InitializeShaders()
 
 void Renderer::ModelsToDraw()
 {
+    
 	m = ResourceManager::Load<Model>("Models/ScaleWidget.obj");
 	EnqueueModel(m);
 	m2 = ResourceManager::Load<Model>("Models/TranslationWidget.obj");
 	EnqueueModel(m2);
 	m3 = ResourceManager::Load<Model>("Models/RotationWidget.obj");
 	EnqueueModel(m3);
+    
 	m_UnitSphere = ResourceManager::Load<Model>("Models/Core/UnitSphere.obj");
 	EnqueueModel(m_UnitSphere);
     m_UnitQuad = ResourceManager::Load<Model>("Models/Core/UnitQuad.obj");
@@ -160,18 +162,22 @@ void Renderer::InputUpdate(double dt)
     glfwGetCursorPos(m_Window, &mousePosX, &mousePosY);
     if (glfwGetMouseButton(m_Window, GLFW_MOUSE_BUTTON_1) == GLFW_PRESS) {
         glm::vec3 data = GetClickedPixelData(mousePosX, m_Resolution.Height - mousePosY);
-        glm::vec2 pixelData = glm::vec2(data);
-        float depthData = data.z;
-        printf("R: %f, G: %f, Depth: %f\n", pixelData.r, pixelData.g, depthData);
+        glm::vec2 color = glm::vec2(data);
+        float depth = data.z;
+        
+        glm::vec3 viewPos = ScreenCoordsToWorldPos(glm::vec2(mousePosX, m_Resolution.Height - mousePosY), depth);
+      //  glm::vec3 worldPos = glm::vec3(glm::inverse(m_Camera->ViewMatrix()) * glm::vec4(viewPos, 1.f));
+
+        //printf("R: %f, G: %f, Depth: %f\n", color.r, color.g, depth);
+        printf("view: x: %f, y: %f z: %f, Length: %f\n", viewPos.x, viewPos.y, viewPos.z, glm::length(viewPos));
 
 
-        if (pixelData != glm::vec2(0, 0)) {
-            const Model* pickModel = m_PickingColorsToModels[pixelData];
+        if (color != glm::vec2(0, 0)) {
+            const Model* pickModel = m_PickingColorsToModels[color];
 
         }
     }
 
-
 	if (glfwGetKey(m_Window, GLFW_KEY_SPACE) == GLFW_PRESS) {
 
 		
@@ -194,6 +200,33 @@ void Renderer::InputUpdate(double dt)
 	m_Camera->SetPosition(m_Position);
 }
 
+
+// Utility functions should be moved to a better place
+glm::vec3 Renderer::ScreenCoordsToWorldPos(glm::vec2 screenCoord, float depth)
+{
+    glm::vec4 pos;
+    float near = m_Camera->NearClip();
+    float far = m_Camera->FarClip();
+
+    glm::vec3 ndc;
+    ndc.x = screenCoord.x / m_Resolution.Width;
+    ndc.y = screenCoord.y / m_Resolution.Height;
+    glm::vec4 clipSpace = glm::vec4(glm::vec2(ndc.x, ndc.y) * 2.0f - 1.0f, (depth) * 2.0f - 1.0f, 1.0f);
+
+    glm::vec4 EyeSpace =  glm::inverse(m_Camera->ProjectionMatrix()) * clipSpace;
+    glm::vec4 WorldSpace = glm::inverse(m_Camera->ViewMatrix()) * EyeSpace;
+    WorldSpace = glm::vec4(glm::vec3(WorldSpace) / WorldSpace.w, 1.f);
+    
+    return glm::vec3(WorldSpace);
+
+}
+
+
+//EntityID Renderer::ScreenCoordsToEntityID(glm::vec2 screenCoord, float depth)
+//{
+//
+//}
+
 void Renderer::Update(double dt)
 {
 	InputUpdate(dt);
@@ -204,6 +237,7 @@ void Renderer::Draw(RenderQueueCollection& rq)
     //TODO: Renderer: Kanske borde vara längst upp i update.
     PickingPass();
     DrawScreenQuad(m_PickingTexture);
+    //DrawScreenQuad(m_DepthBuffer);
     //DrawScene(rq);
 	glfwSwapBuffers(m_Window);
 }