From abffb2fe7c1a1e8d7fe40e465f44731160cd1457 Mon Sep 17 00:00:00 2001
From: Luca Conte <main@lugico.de>
Date: Mon, 24 Jun 2024 14:39:20 +0200
Subject: [PATCH] multiple lights

---
 src/Makefile            |  2 +-
 src/fragmentShader.glsl | 17 +++++++++++------
 src/main.c              |  8 ++++++--
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index bebb830..cd091c7 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,7 +15,7 @@ test.out: test.o $(OBJ)
 	gcc -o $@ test.o $(OBJ) $(ALL_LIBS)
 
 %Shader.c: %Shader.glsl
-	xxd -i $? > $@
+	xxd -i $? | tac | sed "3s/$$/, 0x00/" | tac > $@
 
 main.o: $(SHADERS) matrixMath.h transformation.h wavefrontobj.h sceneGraph.h objectHandler.h shader.h
 
diff --git a/src/fragmentShader.glsl b/src/fragmentShader.glsl
index bf7c06a..04acf12 100644
--- a/src/fragmentShader.glsl
+++ b/src/fragmentShader.glsl
@@ -10,7 +10,9 @@ flat in mat3 TBN;
 uniform float shininess;
 
 uniform vec4 ambientLight;
-uniform vec3 lightPosition;
+uniform vec3 lightPositions[2];
+uniform float lightBrightness[2];
+
 uniform vec4 lightColor;
 
 uniform sampler2D textureSampler;
@@ -27,12 +29,15 @@ void main() {
 
 	vec3 lightDir = normalize(lightPosition - fragmentPosition);
 	vec3 eyeDir = (-normalize(fragmentPosition));
+	for (int i = 0; i < lightPositions.length(); i++) {
+		vec3 lightDir = normalize(lightPositions[i] - fragmentPosition);
 
-	float diff = max(dot(norm, lightDir), 0.0);
 
-	vec3 halfway = (lightDir + eyeDir) / length(lightDir + eyeDir);
-	float specular = pow(max(dot(halfway, norm), 0.0), shininess);
+		sumDiffusion += max(dot(norm, lightDir), 0.0) * lightBrightness[i];
 
+		vec3 halfway = (lightDir + eyeDir) / length(lightDir + eyeDir);
+		sumSpecular += pow(max(dot(halfway, norm), 0.0), shininess);
+	}
 
 	gl_FragColor =
 		// EMISSION
@@ -42,8 +47,8 @@ void main() {
 		ambientLight * color +
 
 		// DIFFUSION
-		color * diff +
+		color * sumDiffusion +
 
 		// SPECULAR
-		specular * lightColor * color;
+		sumSpecular * lightColor * color;
 }
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 7246cdb..417d861 100644
--- a/src/main.c
+++ b/src/main.c
@@ -296,13 +296,17 @@ void draw(void) {
     glUniformMatrix4fv(glGetUniformLocation(program, "projection"), 1, GL_FALSE, (GLfloat*)&projection);
 
     // SET LIGHT DATA
-    glUniform4f(glGetUniformLocation(program, "lightColor"), 1.0f, 1.0f, 1.0f, 1.0f);
+    glUniform4f(glGetUniformLocation(program, "lightColor"), 0.2f, 0.2f, 0.2f, 0.5f);
     glUniform4f(glGetUniformLocation(program, "ambientLight"), 0.05f, 0.05f, 0.05f, 1.0f);
 
     vec4 lightPosition = {cos(stepi) * 5.0f, 5.0f, sin(stepi) * 5.0f, 1.0f};
     multiplyAny((GLfloat*)&lightPosition, (GLfloat*)&viewingTransformation, (GLfloat*)&lightPosition, 4, 4, 1);
 
-    glUniform3f(glGetUniformLocation(program, "lightPosition"), lightPosition.x, lightPosition.y, lightPosition.z);
+    glUniform3f(glGetUniformLocation(program, "lightPositions[0]"), lightPosition.x, lightPosition.y, lightPosition.z);
+    glUniform3f(glGetUniformLocation(program, "lightPositions[1]"), -lightPosition.x, lightPosition.y, -lightPosition.z);
+
+    glUniform1f(glGetUniformLocation(program, "lightBrightness[0]"), 0.5f);
+    glUniform1f(glGetUniformLocation(program, "lightBrightness[1]"), 0.5f);
 
 
     renderSceneNode(rootNode);