src/engine/render.c

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