From 6d3965b35edf5f03cd065d42af31867acf1f4637 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <matthias@gamezock.de>
Date: Thu, 24 Dec 2009 02:47:35 +0100
Subject: Make shadow volumes visible

---
 src/Game.cpp | 81 ++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 49 insertions(+), 32 deletions(-)

(limited to 'src/Game.cpp')

diff --git a/src/Game.cpp b/src/Game.cpp
index 205125a..1b23222 100644
--- a/src/Game.cpp
+++ b/src/Game.cpp
@@ -30,27 +30,21 @@
 
 namespace Zoom {
 
-Game::Game(bool multisample) : playerPos(vmml::vec3f::ZERO), playerRotY(vmml::mat4f::IDENTITY), playerRotX(0),
+Game::Game() : playerPos(vmml::vec3f::ZERO), playerRotY(vmml::mat4f::IDENTITY), playerRotX(0),
     input(0), lightPos(0) {
-  glClearColor(0.0, 0.0, 0.0, 1.0);
-  glClearDepth(1.0);
   glEnable(GL_DEPTH_TEST);
+  glEnable(GL_STENCIL_TEST);
 
   glEnable(GL_BLEND);
 
-#ifndef _WIN32
-  if(multisample)
-    glEnable(GL_MULTISAMPLE_ARB);
-#endif
+  glEnable(GL_MULTISAMPLE_ARB);
 
   glLightModelfv(GL_LIGHT_MODEL_AMBIENT, vmml::vec4f(0.1, 0.1, 0.1, 1).array);
 
   glLightfv(GL_LIGHT0, GL_AMBIENT, vmml::vec4f::ZERO.array);
   glLightfv(GL_LIGHT0, GL_DIFFUSE, vmml::vec4f::ONE.array);
   glLightfv(GL_LIGHT0, GL_SPECULAR, vmml::vec4f::ONE.array);
-  glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 0);
   glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.2);
-  glDisable(GL_LIGHT0);
 
   glEnable(GL_COLOR_MATERIAL);
   glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
@@ -72,6 +66,20 @@ bool Game::loadLevel(const std::string &name) {
   return level;
 }
 
+void Game::resize(int width, int height) {
+  if(height == 0) {
+    height = 1;
+  }
+
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadMatrixf(MathUtil::perspective(50.0f, (float)width/(float)height, 0.1).array);
+
+  glMatrixMode(GL_MODELVIEW);
+
+  glViewport(0, 0, width, height);
+}
+
 void Game::turn(float x, float y) {
   playerRotY.rotate_y(-x*M_PI/180/10);
 
@@ -107,29 +115,29 @@ void Game::run(int delta) {
 
 void Game::render() {
   int i;
-  float light[] = {0, 0, 0, 1};
+  vmml::vec3f light(vmml::vec3f::ZERO);
 
   if(lightPos < 12000) i = lightPos;
   else i = 24000 - lightPos;
 
   if(i < 4000) {
-    light[0] = 0.0;
-    light[2] = -i * 0.001;
+    light.x() = 0.0;
+    light.z() = -i * 0.001;
   }
   else if(i < 8000) {
-    light[0] = (i-4000) * 0.001;
-    light[2] = -4.0;
+    light.x() = (i-4000) * 0.001;
+    light.z() = -4.0;
   }
   else if(i < 12000) {
-    light[0] = 4.0;
-    light[2] = -4.0 - (i-8000) * 0.001;
+    light.x() = 4.0;
+    light.z() = -4.0 - (i-8000) * 0.001;
   }
   else {
-    light[0] = 4.0;
-    light[2] = -8.0;
+    light.x() = 4.0;
+    light.z() = -8.0;
   }
 
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
 
   vmml::mat4f transform(playerRotY), inverse;
   transform.rotate_x(playerRotX);
@@ -138,28 +146,37 @@ void Game::render() {
 
   glLoadMatrixf(inverse.array);
 
-  glLightfv(GL_LIGHT0, GL_POSITION, light);
-
-  renderer.render(triangles);
+  renderer.render(triangles, light);
 
   Shader::disable();
-  glDepthFunc(GL_LEQUAL);
-  glBlendFunc(GL_ONE, GL_ZERO);
+  glDepthMask(GL_FALSE);
+  glBlendFunc(GL_ONE, GL_ONE);
+  glBlendEquation(GL_FUNC_ADD);
+  glDepthFunc(GL_GREATER);
+  glColor3f(0.05, 0.05, 0.05);
+  glFrontFace(GL_CCW);
 
-  glBegin(GL_LINES);
+  glBegin(GL_TRIANGLES);
+  for(std::vector<BSPTree::TriangleRecord>::iterator t = triangles.begin(); t != triangles.end(); ++t) {
+    ShadowVolume v(t->triangle, light);
+    v.render();
+  }
+  glEnd();
 
-  glColor3f(1, 1, 0);
+  glFrontFace(GL_CW);
+  glBlendEquation(GL_FUNC_REVERSE_SUBTRACT);
 
+  glBegin(GL_TRIANGLES);
   for(std::vector<BSPTree::TriangleRecord>::iterator t = triangles.begin(); t != triangles.end(); ++t) {
     ShadowVolume v(t->triangle, light);
-
-    for(int i = 0; i < 3; ++i) {
-      glVertex3fv(v.getVertex(i).array);
-      glVertex3fv((v.getVertex(i)+v.getDirection(i)).array);
-    }
+    v.render();
   }
-
   glEnd();
+
+  glFrontFace(GL_CCW);
+  glDepthMask(GL_TRUE);
+  glDepthFunc(GL_LEQUAL);
+  glBlendEquation(GL_FUNC_ADD);
 }
 
 }
-- 
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