working lights!

- fix positions of lights
- fix normal vector bug (mat4->mat3)
- change light color

res/shaders/simple.frag

@@ -17,7 +17,7 @@ float dither(vec2 uv) {
 }
 
 const vec3 objectColor = vec3(1.0, 1.0, 1.0);
-const vec3 lightColor = vec3(1.0, 1.0, 1.0);
+const vec3 lightColor = vec3(0.5, 0.5, 0.5);
 const float ambientStrength = 0.1;
 const float specularStrength = 0.5;
 const float shininess = 32.0;
@@ -35,7 +35,7 @@ void main()
         float diff = max(dot(norm, lightDir), 0.0);
         vec3 diffuse = diff * lightColor;
 
-        vec3 halfwayDir = normalize(lightDir + viewDir);
+        vec3 halfwayDir = normalize(lightDir + viewDir); // little optimization (blinn-phong)
         float spec = pow(max(dot(norm, halfwayDir), 0.0), shininess);
         vec3 specular = specularStrength * spec * lightColor;
 

src/gamelogic.cpp

@@ -146,22 +146,14 @@ void initGame(GLFWwindow* window, CommandLineOptions gameOptions) {
     auto padLight = lightNodes.at(1);
     auto ballLight = lightNodes.at(2);
 
-    ceilingLight->position = {
-        boxDimensions.x / 2,
-        boxDimensions.y,
-        boxDimensions.z / 2
-    };
-    rootNode->children.push_back(ceilingLight);
+    boxNode->children.push_back(ceilingLight);
+    ceilingLight->position = { 0, 10, 0 };
 
-    padLight->position = {
-        padPositionX,
-        50,
-        padPositionZ
-    };
     padNode->children.push_back(padLight);
+    padLight->position = { 0, 10, 0 };
 
-    ballLight->position = ballPosition;
     ballNode->children.push_back(ballLight);
+    ballLight->position = { 0, 0, 0 };
 
     rootNode->children.push_back(boxNode);
     rootNode->children.push_back(padNode);
@@ -370,14 +362,15 @@ void updateFrame(GLFWwindow* window) {
         boxNode->position.z - (boxDimensions.z/2) + (padDimensions.z/2) + (1 - padPositionZ) * (boxDimensions.z - padDimensions.z)
     };
 
-    updateNodeTransformations(rootNode, VP);
+    updateNodeTransformations(rootNode, VP, glm::mat4(1.0f));  // Pass identity for initial model matrix
 
+    lightCoords.clear();
     for (auto* light : lightNodes) {
         lightCoords.push_back(light->worldPosition);
     }
 }
 
-void updateNodeTransformations(SceneNode* node, glm::mat4 transformationThusFar) {
+void updateNodeTransformations(SceneNode* node, glm::mat4 transformationThusFar, glm::mat4 modelMatrixThusFar) {
     glm::mat4 transformationMatrix =
               glm::translate(node->position)
             * glm::translate(node->referencePoint)
@@ -387,23 +380,24 @@ void updateNodeTransformations(SceneNode* node, glm::mat4 transformationThusFar)
             * glm::scale(node->scale)
             * glm::translate(-node->referencePoint);
 
-    node->currentTransformationMatrix = transformationThusFar * transformationMatrix;
-    node->modelMatrix = transformationMatrix;
+    node->currentTransformationMatrix = transformationThusFar * transformationMatrix;  // MVP
+    node->modelMatrix = modelMatrixThusFar * transformationMatrix;  // Accumulated world transform
     node->normalMatrix = glm::transpose(glm::inverse(glm::mat3(node->modelMatrix)));
 
     switch(node->nodeType) {
         case GEOMETRY: break;
         case POINT_LIGHT:
-            node->worldPosition = glm::vec3(node->currentTransformationMatrix * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+            node->worldPosition = glm::vec3(node->modelMatrix * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
             break;
         case SPOT_LIGHT: break;
     }
 
     for(SceneNode* child : node->children) {
-        updateNodeTransformations(child, node->currentTransformationMatrix);
+        updateNodeTransformations(child, node->currentTransformationMatrix, node->modelMatrix);
     }
 }
 
+
 void renderNode(SceneNode* node) {
     glUniformMatrix4fv(3, 1, GL_FALSE, glm::value_ptr(node->currentTransformationMatrix));
     glUniformMatrix4fv(4, 1, GL_FALSE, glm::value_ptr(node->modelMatrix));

src/gamelogic.h

@@ -5,7 +5,7 @@
 #include <utilities/window.hpp>
 #include "sceneGraph.hpp"
 
-void updateNodeTransformations(SceneNode* node, glm::mat4 transformationThusFar);
+void updateNodeTransformations(SceneNode* node, glm::mat4 transformationThusFar, glm::mat4 modelMatrixThusFar);
 void initGame(GLFWwindow* window, CommandLineOptions options);
 void updateFrame(GLFWwindow* window);
-void renderFrame(GLFWwindow* window);
+void renderFrame(GLFWwindow* window);

src/program.cpp

@@ -1,5 +1,6 @@
 // Local headers
 #include "program.hpp"
+#include "glad/glad.h"
 #include "utilities/window.hpp"
 #include "gamelogic.h"
 #include <glm/glm.hpp>

src/sceneGraph.hpp

@@ -48,7 +48,7 @@ struct SceneNode {
 	glm::mat4 modelMatrix; // m
 
 	// pre-computed normal transformation matrix, (m^-1)^T
-	glm::mat4 normalMatrix;
+	glm::mat3 normalMatrix;
 
 	// The location of the node's reference point
 	glm::vec3 referencePoint;