From fc2d4c5028079899a5c7d58eccaa67069dd1c91b Mon Sep 17 00:00:00 2001
From: Andreas Ortmann <ortmann@finf.uni-hannover.de>
Date: Mon, 3 Oct 2016 10:47:02 +0200
Subject: [PATCH] explosions make light now.

---
 data/shader/gameobjects.frag                  | 30 ++++++++++++-
 data/shader/particle.frag                     |  1 -
 data/shader/particle.vert                     |  2 -
 game/renderer_polygon_3d/particle_batch.cpp   |  9 +++-
 game/renderer_polygon_3d/particle_batch.hpp   |  8 +++-
 .../renderer_polygon_3d.cpp                   | 42 ++++++++++++++++---
 .../renderer_polygon_3d.hpp                   |  2 +-
 7 files changed, 81 insertions(+), 13 deletions(-)

diff --git a/data/shader/gameobjects.frag b/data/shader/gameobjects.frag
index afc73bf..5b404a3 100644
--- a/data/shader/gameobjects.frag
+++ b/data/shader/gameobjects.frag
@@ -10,6 +10,10 @@ uniform vec3  materialColor;
 uniform int   materialKind;
 uniform int   materialSeed;
 
+uniform int   explLightsNum;
+uniform vec3  explLightsPos[10];
+uniform float explLightsIntensities[10];
+
 void main()
 {
   vec3 Eye       = normalize(-vertex);
@@ -27,7 +31,31 @@ void main()
   vec3 color = materialColor;
   color = max(vec3(0.0), min(vec3(1.0), color));
 
-  vec3 IDiffuse  = vec3(color) * lightColor * max(dot(normal, lightDirection), 0.0);
+  //vec3 light = lightColor * max(dot(normal, lightDirection), 0.0);
+  vec3 light = vec3(0.0);
+
+  int i;
+  for (i=0; i<explLightsNum; i++) {
+    vec3 explLightColor = vec3(1.0, 0.8, 0.3);
+    vec3 diff = vertex - explLightsPos[i];
+    float l = 10.0*length(diff);
+    float dir = max(0.0, -dot(normal, diff));
+    float dp = max(0.0, 1.0-l);
+
+    float intensity = 10.0;
+    if (dp == 0.0) {
+        intensity *= dir;
+    } else {
+        intensity *= dp;
+    }
+    intensity /= 1.0 + 0.5*l*l;
+
+    light += intensity * pow(explLightsIntensities[i], 2.0) * explLightColor;
+  }
+
+  light = max(vec3(0.0), light);
+
+  vec3 IDiffuse  = vec3(color) * light;
 
   // TODO make instensity/exponent as parameter
   //vec3 ISpecular = lightColor * 5.0 * pow(max(dot(Reflected, Eye), 0.0), 2.0);
diff --git a/data/shader/particle.frag b/data/shader/particle.frag
index 98e8854..08c24de 100644
--- a/data/shader/particle.frag
+++ b/data/shader/particle.frag
@@ -1,5 +1,4 @@
 #version 120
-varying vec3  position;
 varying vec2  vertex;
 varying vec3  velocity;
 varying float decay;
diff --git a/data/shader/particle.vert b/data/shader/particle.vert
index a064753..30242f0 100644
--- a/data/shader/particle.vert
+++ b/data/shader/particle.vert
@@ -14,7 +14,6 @@ varying float decay;
 varying vec3  velocity;
 varying vec2  vertex;
 varying float explCenterDist;
-varying vec3  position;
 
 uniform float aspectRatio;
 
@@ -47,7 +46,6 @@ void main()
 
   vertex   = base.xy;
   velocity = in_velocity;
-  position = in_position;
 
   explCenterDist = length(explCenter - offset);
 }
\ No newline at end of file
diff --git a/game/renderer_polygon_3d/particle_batch.cpp b/game/renderer_polygon_3d/particle_batch.cpp
index 8189c83..61569a3 100644
--- a/game/renderer_polygon_3d/particle_batch.cpp
+++ b/game/renderer_polygon_3d/particle_batch.cpp
@@ -15,8 +15,13 @@ namespace endofthejedi {
         : m_id(id)
         , m_numParticles(numParticles)
         , m_particleRadius(particleSize)
-        , m_halfAge(halfAge)
         , m_age(0.0)
+        , m_halfAge(halfAge)
+
+        // XXX this is used in some places in the shader.
+        // set it via uniform too
+        , m_maxNumHalfAges(5.0)
+
         , m_maxVelocity(1.0)
         , m_center(glm::vec3(0.0f, 0.0f, 0.0f))
 
@@ -207,6 +212,6 @@ namespace endofthejedi {
 
     bool ParticleBatch::done() const
     {
-        return m_age >= 5.0*m_halfAge;
+        return m_age >= m_maxNumHalfAges*m_halfAge;
     }
 }
diff --git a/game/renderer_polygon_3d/particle_batch.hpp b/game/renderer_polygon_3d/particle_batch.hpp
index 5b7bc69..648e0f7 100644
--- a/game/renderer_polygon_3d/particle_batch.hpp
+++ b/game/renderer_polygon_3d/particle_batch.hpp
@@ -36,10 +36,15 @@ namespace endofthejedi {
             void render(Shader *shader);
 
             void tick(float dt);
+            float ageNormalized() const { return m_age / (m_maxNumHalfAges*m_halfAge); }
+            float age() const { return m_age; }
             bool done() const;
 
             size_t id() const { return m_id; }
 
+
+            const glm::vec3 &explosionCenter() const { return m_center; }
+
         private:
             size_t dataSizeForIndex(size_t index);
             void  *dataSourceForIndex(size_t index);
@@ -51,8 +56,9 @@ namespace endofthejedi {
             // uniforms for the shader
             size_t                 m_numParticles;
             float                  m_particleRadius;
-            const float            m_halfAge;
             float                  m_age;
+            const float            m_halfAge;
+            const float            m_maxNumHalfAges;
             float                  m_maxVelocity;
             glm::vec3              m_center;
 
diff --git a/game/renderer_polygon_3d/renderer_polygon_3d.cpp b/game/renderer_polygon_3d/renderer_polygon_3d.cpp
index fc56aa9..0ea580e 100644
--- a/game/renderer_polygon_3d/renderer_polygon_3d.cpp
+++ b/game/renderer_polygon_3d/renderer_polygon_3d.cpp
@@ -29,7 +29,7 @@ namespace endofthejedi {
 
         //addModel("../data/mesh/small_atomic_bomb.stl", &m_missileModel);
         addModel("../data/mesh/rocket.stl",    &m_missileModel);
-        addModel("../data/mesh/planet_12.stl", &m_planetModel);
+        addModel("../data/mesh/planet_128.stl", &m_planetModel);
         addModel("../data/mesh/ship_ufo.stl",  &m_shipModel);
     }
 
@@ -60,7 +60,7 @@ namespace endofthejedi {
         // TODO: add ONE sun planet
         // TODO: add lights for explosions
 
-        configureLightningInShader();
+        configureLightningInShader(&m_shader_game_objects);
 
         //std::cout<<"setting aspect ratio: " << m_aspectRatio << std::endl;
         glUniform1f(m_shader_game_objects.location("aspectRatio"), m_aspectRatio);
@@ -452,7 +452,7 @@ namespace endofthejedi {
         glPolygonMode(GL_FRONT, GL_FILL);
     }
 
-    void RendererPolygon3d::configureLightningInShader()
+    void RendererPolygon3d::configureLightningInShader(Shader *shader) const
     {
         // TODO: add a few small lights for explosions so they lit the
         // surroundsings
@@ -469,8 +469,40 @@ namespace endofthejedi {
             }
         }
 
-        glUniform3f(m_shader_game_objects.location("lightPosition"), p.x, p.y, p.z);
-        glUniform3f(m_shader_game_objects.location("lightColor"),    c.x, c.y, c.z);
+        glUniform3f(shader->location("lightPosition"), p.x, p.y, p.z);
+        glUniform3f(shader->location("lightColor"),    c.x, c.y, c.z);
+
+        std::vector<glm::vec3> positions;
+        std::vector<float> intensities;
+
+        size_t numExplLights = 0;
+
+        for (ParticleBatch *batch : m_particles) {
+            float age = batch->ageNormalized();
+            // TODO: use function with a peak for this:
+            //
+            //   /\__
+            // _/    \--____
+
+            float intensity = 1.0-age;
+            glm::vec3 p = batch->explosionCenter();
+
+            intensities.push_back(intensity);
+            positions.push_back(p);
+
+            numExplLights++;
+
+            if (numExplLights == 10) {
+                break;
+            }
+        }
+
+        glUniform1i( shader->location("explLightsNum"), numExplLights);
+
+        if (numExplLights != 0) {
+            glUniform3fv(shader->location("explLightsPos"),         numExplLights, glm::value_ptr(positions[0]));
+            glUniform1fv(shader->location("explLightsIntensities"), numExplLights, intensities.data());
+        }
     }
 
     void RendererPolygon3d::setWindowSize(int px, int py)
diff --git a/game/renderer_polygon_3d/renderer_polygon_3d.hpp b/game/renderer_polygon_3d/renderer_polygon_3d.hpp
index 5f0f1b6..bfd3d1b 100644
--- a/game/renderer_polygon_3d/renderer_polygon_3d.hpp
+++ b/game/renderer_polygon_3d/renderer_polygon_3d.hpp
@@ -59,7 +59,7 @@ namespace endofthejedi {
 
             void renderTraces();
 
-            void configureLightningInShader();
+            void configureLightningInShader(Shader *shader) const;
 
         private:
             // all models are also here (for easy reloading etc.)