src/engine/render.c

   1 #include <GL/glut.h>
   2 #include <stdbool.h>
   3
   4 #include "game/level.h"
   5 #include "game/player.h"
   6
   7 #include "geometry.h"
   8 #include "performance.h"
   9 #include "scene.h"
  10
  11 const float AXIS_RADIUS = 5.0f;
  12
  13 static void setupCamera();
  14 static void moveCameraTo(const Vector3D pos);
  15 static void drawAxes();
  16 static void renderBlockGrid(const BlockGrid grid);
  17 static void renderCharacter(const Character* character, const Vector3D pos);
  18 static void drawSolid(const Solid* solid);
  19
  20 float viewportAspectRatio = 1.0f;
  21
  22 void initRender() {
  23         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  24
  25         GLfloat light0_ambient[] = {0.1f, 0.1f, 0.1f, 1.0f};
  26         GLfloat light0_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f};
  27         GLfloat light0_specular[] = {0.96f, 0.98f, 1.0f, 1.0f};
  28         GLfloat light0_position[] = {5.0f, 10.0f, 5.0f, 0.0f}; // (w == 0.0f) == directional
  29
  30         glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
  31         glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
  32         glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
  33         glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
  34
  35         glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 1.0f);
  36         glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 0.05f);
  37         glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.005f);
  38 }
  39
  40
  41
  42 void renderSceneNew(const Scene*);
  43
  44 void renderFrame() {
  45         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  46
  47         glEnable(GL_NORMALIZE);
  48         glEnable(GL_CULL_FACE);
  49         glEnable(GL_DEPTH_TEST);
  50
  51         setupCamera();
  52         moveCameraTo(playerPos);
  53
  54         renderSceneNew(currentScene);
  55
  56         glFlush();
  57         glutSwapBuffers();
  58         frameRendered();
  59         glutPostRedisplay();
  60 }
  61
  62 void renderSceneNew(const Scene* scene) {
  63         if (!scene) {
  64                 return;
  65         }
  66
  67         glMatrixMode(GL_MODELVIEW);
  68         glLoadMatrixf((const GLfloat*) &scene->transform);
  69
  70         glDisable(GL_LIGHTING);
  71         drawAxes();
  72         glEnable(GL_LIGHTING);
  73
  74         if (scene->solid) {
  75                 glEnable(GL_LIGHT0);
  76                 glEnable(GL_TEXTURE_2D);
  77                 drawSolid(scene->solid);
  78                 glDisable(GL_TEXTURE_2D);
  79                 glDisable(GL_LIGHT0);
  80         }
  81
  82         for (size_t i = 0; i < scene->numChildren; ++i) {
  83                 renderSceneNew(scene->children[i]);
  84         }
  85 }
  86
  87
  88
  89 void renderScene() {
  90         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  91
  92         glEnable(GL_NORMALIZE);
  93         glEnable(GL_CULL_FACE);
  94         glEnable(GL_DEPTH_TEST);
  95
  96         setupCamera();
  97         moveCameraTo(playerPos);
  98
  99         glDisable(GL_LIGHTING);
 100         drawAxes();
 101         glEnable(GL_LIGHTING);
 102
 103         glEnable(GL_LIGHT0);
 104         glEnable(GL_TEXTURE_2D);
 105         renderBlockGrid(levelGrid);
 106         renderCharacter(&playerCharacter, playerPos);
 107         glDisable(GL_TEXTURE_2D);
 108         glDisable(GL_LIGHT0);
 109
 110         glFlush();
 111         glutSwapBuffers();
 112         frameRendered();
 113         glutPostRedisplay();
 114 }
 115
 116 static void setupCamera() {
 117         glMatrixMode(GL_PROJECTION);
 118         glLoadIdentity();
 119         glOrtho(-16.0,
 120                 16.0,
 121                 -16.0/viewportAspectRatio,
 122                 16.0/viewportAspectRatio,
 123                 -128.0,
 124                 128.0);
 125         glRotatef(45.0f, 1.0f, 0.0f, 0.0f);
 126         glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
 127 }
 128
 129 static void moveCameraTo(const Vector3D pos) {
 130         glMatrixMode(GL_PROJECTION);
 131         glTranslatef(-pos.x, -pos.y, -pos.z);
 132 }
 133
 134 static void drawAxes() {
 135         glMatrixMode(GL_MODELVIEW);
 136         // X axis
 137         glColor3f(1.0f, 0.0f, 0.0f);
 138         glBegin(GL_LINES);
 139         glVertex3f(0.0f, 0.0f, 0.0f);
 140         glVertex3f(AXIS_RADIUS, 0.0f, 0.0f);
 141         glEnd();
 142         // Y axis
 143         glColor3f(0.0f, 1.0f, 0.0f);
 144         glBegin(GL_LINES);
 145         glVertex3f(0.0f, 0.0f, 0.0f);
 146         glVertex3f(0.0f, AXIS_RADIUS, 0.0f);
 147         glEnd();
 148         // Z axis
 149         glColor3f(0.0f, 0.0f, 1.0f);
 150         glBegin(GL_LINES);
 151         glVertex3f(0.0f, 0.0f, 0.0f);
 152         glVertex3f(0.0f, 0.0f, AXIS_RADIUS);
 153         glEnd();
 154 }
 155
 156 static void renderBlockGrid(const BlockGrid grid) {
 157         glMatrixMode(GL_MODELVIEW);
 158         for (size_t z = 0; z < grid.depth; ++z) {
 159                 glLoadIdentity();
 160                 glTranslatef(0.0f, 0.0f, z * BLOCKGRID_CELL_SIZE);
 161                 for (size_t x = 0; x < grid.width; ++x) {
 162                         drawSolid(getBlockFromGrid(grid, x, z)->solid);
 163                         glTranslatef(BLOCKGRID_CELL_SIZE, 0.0f, 0.0f);
 164                 }
 165         }
 166         glLoadIdentity();
 167 }
 168
 169 static void renderCharacter(const Character* character, const Vector3D pos) {
 170         glMatrixMode(GL_MODELVIEW);
 171         glTranslatef(pos.x, pos.y, pos.z);
 172         drawSolid(character->solid);
 173         glLoadIdentity();
 174 }
 175
 176 static void drawSolid(const Solid* solid) {
 177         if (solid == NULL) {
 178                 return;
 179         }
 180
 181         glMatrixMode(GL_MODELVIEW);
 182         glColor3f(0.5f, 1.0f, 0.0f);
 183
 184         for (size_t meshIndex = 0; meshIndex < solid->numMeshes; ++meshIndex) {
 185                 const Mesh mesh = solid->meshes[meshIndex];
 186                 glBindTexture(GL_TEXTURE_2D,
 187                               solid->materials[mesh.materialIndex].textureId);
 188                 bool hasNormals = mesh.normals != NULL;
 189                 bool hasTextureCoords = mesh.textureCoords != NULL;
 190
 191                 for (size_t faceIndex = 0; faceIndex < mesh.numFaces; ++faceIndex) {
 192                         const Face face = mesh.faces[faceIndex];
 193
 194                         GLenum faceMode;
 195                         switch (face.numIndices) {
 196                                 case 1: faceMode = GL_POINTS; break;
 197                                 case 2: faceMode = GL_LINES; break;
 198                                 case 3: faceMode = GL_TRIANGLES; break;
 199                                 default: faceMode = GL_POLYGON; break;
 200                         }
 201
 202                         glBegin(faceMode);
 203
 204                         for (size_t i = 0; i < face.numIndices; ++i) {
 205                                 size_t vertIndex = face.indices[i];
 206                                 if (hasNormals) {
 207                                         if (hasTextureCoords) {
 208                                                 Vector3D coords = mesh.textureCoords[vertIndex];
 209                                                 glTexCoord2f(coords.x, coords.y);
 210                                         }
 211                                         Vector3D normal = mesh.normals[vertIndex];
 212                                         glNormal3f(normal.x, normal.y, normal.z);
 213                                 }
 214                                 Vector3D vertex = mesh.vertices[vertIndex];
 215                                 glVertex3f(vertex.x, vertex.y, vertex.z);
 216                         }
 217
 218                         glEnd();
 219                 }
 220         }
 221         glBindTexture(GL_TEXTURE_2D, 0);
 222 }