src/engine/render.c

   1 #include "render.h"
   2
   3 #include "geometry.h"
   4 #include "performance.h"
   5
   6 #include "game/player.h"
   7
   8 float viewportAspectRatio = 1.0f;
   9 const Scene* cameraAnchor;
  10 bool debugScene = false;
  11 bool debugRender = false;
  12
  13 static const float AXIS_RADIUS = 5.0f;
  14
  15 static void renderScene(const Scene*, const Transform baseTransform);
  16 static void setupCamera();
  17 static void moveCameraTo(const Scene* scene);
  18 static void drawAxes();
  19 static void drawSolid(const Solid* solid);
  20
  21
  22
  23 void initRender() {
  24         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  25
  26         GLfloat light0_ambient[] = {0.1f, 0.1f, 0.1f, 1.0f};
  27         GLfloat light0_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f};
  28         GLfloat light0_specular[] = {0.96f, 0.98f, 1.0f, 1.0f};
  29         GLfloat light0_position[] = {5.0f, 10.0f, 5.0f, 0.0f}; // (w == 0.0f) == directional
  30
  31         glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
  32         glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
  33         glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
  34         glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
  35
  36         glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 1.0f);
  37         glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 0.05f);
  38         glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.005f);
  39
  40         //glShadeModel(GL_FLAT);
  41 }
  42
  43 void renderFrame(GLFWwindow* window) {
  44         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  45
  46         glEnable(GL_NORMALIZE);
  47         glEnable(GL_CULL_FACE);
  48         glEnable(GL_DEPTH_TEST);
  49
  50         setupCamera();
  51         moveCameraTo(cameraAnchor);
  52
  53         renderScene(currentScene, identity());
  54
  55         glFlush();
  56         glfwSwapBuffers(window);
  57         frameRendered();
  58 }
  59
  60 static void renderScene(const Scene* scene, const Transform baseTransform) {
  61         if (!scene) {
  62                 return;
  63         }
  64
  65         Transform transform = multiply(scene->transform, baseTransform);
  66
  67         glMatrixMode(GL_MODELVIEW);
  68         glLoadTransposeMatrixf((const GLfloat*) &transform);
  69
  70         glDisable(GL_LIGHTING);
  71
  72         if (debugScene || scene == playerProjectedMovement) {
  73                 drawAxes();
  74         }
  75
  76         glEnable(GL_LIGHTING);
  77
  78         if (scene->solid) {
  79                 glEnable(GL_LIGHT0);
  80                 glEnable(GL_TEXTURE_2D);
  81                 drawSolid(scene->solid);
  82                 glDisable(GL_TEXTURE_2D);
  83                 glDisable(GL_LIGHT0);
  84         }
  85
  86         for (size_t i = 0; i < scene->numChildren; ++i) {
  87                 renderScene(scene->children[i], transform);
  88         }
  89 }
  90
  91 static void setupCamera() {
  92         glMatrixMode(GL_PROJECTION);
  93         glLoadIdentity();
  94         glOrtho(-16.0,
  95                 16.0,
  96                 -16.0/viewportAspectRatio,
  97                 16.0/viewportAspectRatio,
  98                 -128.0,
  99                 128.0);
 100         glRotatef(45.0f, 1.0f, 0.0f, 0.0f);
 101         glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
 102 }
 103
 104 static void moveCameraTo(const Scene* anchor) {
 105         glMatrixMode(GL_PROJECTION);
 106         Vector pos = translationOf(worldTransform(anchor));
 107         glTranslatef(-pos.x, -pos.y, -pos.z);
 108 }
 109
 110 static void drawAxes() {
 111         glMatrixMode(GL_MODELVIEW);
 112         // X axis
 113         glColor3f(1.0f, 0.0f, 0.0f);
 114         glBegin(GL_LINES);
 115         glVertex3f(0.0f, 0.0f, 0.0f);
 116         glVertex3f(AXIS_RADIUS, 0.0f, 0.0f);
 117         glEnd();
 118         // Y axis
 119         glColor3f(0.0f, 1.0f, 0.0f);
 120         glBegin(GL_LINES);
 121         glVertex3f(0.0f, 0.0f, 0.0f);
 122         glVertex3f(0.0f, AXIS_RADIUS, 0.0f);
 123         glEnd();
 124         // Z axis
 125         glColor3f(0.0f, 0.0f, 1.0f);
 126         glBegin(GL_LINES);
 127         glVertex3f(0.0f, 0.0f, 0.0f);
 128         glVertex3f(0.0f, 0.0f, AXIS_RADIUS);
 129         glEnd();
 130 }
 131
 132 static GLfloat absolute(GLfloat a) {
 133         return a < 0 ? -a : a;
 134 }
 135
 136 static void drawSolid(const Solid* solid) {
 137         if (solid == NULL) {
 138                 return;
 139         }
 140
 141         glMatrixMode(GL_MODELVIEW);
 142         glColor3f(0.5f, 1.0f, 0.0f);
 143
 144         for (size_t meshIndex = 0; meshIndex < solid->numMeshes; ++meshIndex) {
 145                 const Mesh mesh = solid->meshes[meshIndex];
 146                 glBindTexture(GL_TEXTURE_2D,
 147                               solid->materials[mesh.materialIndex].textureId);
 148
 149                 for (size_t faceIndex = 0; faceIndex < mesh.numFaces; ++faceIndex) {
 150                         const Face face = mesh.faces[faceIndex];
 151
 152                         if (debugRender && face.normals) {
 153                                 glDisable(GL_LIGHTING);
 154                                 glDisable(GL_TEXTURE_2D);
 155                                 glBegin(GL_LINES);
 156                                 for (size_t i = 0; i < face.numIndices; ++i) {
 157                                         size_t vertIndex = face.indices[i];
 158                                         Vector vertex = mesh.vertices[vertIndex];
 159                                         Vector normal = face.normals[i];
 160                                         glColor3f(absolute(normal.x), absolute(normal.y), absolute(normal.z));
 161                                         glVertex3f(vertex.x, vertex.y, vertex.z);
 162                                         glVertex3f(vertex.x + normal.x, vertex.y + normal.y, vertex.z + normal.z);
 163                                 }
 164                                 glEnd();
 165                                 glEnable(GL_TEXTURE_2D);
 166                                 glEnable(GL_LIGHTING);
 167                         }
 168
 169                         GLenum faceMode;
 170                         switch (face.numIndices) {
 171                                 case 1: faceMode = GL_POINTS; break;
 172                                 case 2: faceMode = GL_LINES; break;
 173                                 case 3: faceMode = GL_TRIANGLES; break;
 174                                 default: faceMode = GL_POLYGON; break;
 175                         }
 176
 177                         glBegin(faceMode);
 178
 179                         for (size_t i = 0; i < face.numIndices; ++i) {
 180                                 size_t vertIndex = face.indices[i];
 181                                 if (face.normals) {
 182                                         if (mesh.textureCoords) {
 183                                                 Vector coords = mesh.textureCoords[vertIndex];
 184                                                 glTexCoord2f(coords.x, coords.y);
 185                                         }
 186                                         Vector normal = face.normals[i];
 187                                         glNormal3f(normal.x, normal.y, normal.z);
 188                                 }
 189
 190                                 Vector vertex = mesh.vertices[vertIndex];
 191                                 glVertex3f(vertex.x, vertex.y, vertex.z);
 192                         }
 193
 194                         glEnd();
 195                 }
 196         }
 197         glBindTexture(GL_TEXTURE_2D, 0);
 198 }