src/engine/render.c

   1 #include <GL/glut.h>
   2 #include <stdbool.h>
   3
   4 #include "level.h"
   5 #include "performance.h"
   6 #include "player.h"
   7 #include "typedefs.h"
   8
   9 const float AXIS_RADIUS = 5.0f;
  10
  11 static void setupCamera();
  12 static void moveCameraTo(const Vector3D pos);
  13 static void drawAxes();
  14 static void renderBlockGrid(const BlockGrid grid);
  15 static void renderCharacter(const Character* character, const Vector3D pos);
  16 static void drawAsset3D(const Asset3D* asset3D);
  17
  18 float viewportAspectRatio = 1.0f;
  19
  20
  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 void renderScene() {
  41         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  42
  43         glEnable(GL_NORMALIZE);
  44         glEnable(GL_CULL_FACE);
  45         glEnable(GL_DEPTH_TEST);
  46
  47         setupCamera();
  48         moveCameraTo(playerPos);
  49
  50         glDisable(GL_LIGHTING);
  51         drawAxes();
  52         glEnable(GL_LIGHTING);
  53
  54         glEnable(GL_LIGHT0);
  55         glEnable(GL_TEXTURE_2D);
  56         renderBlockGrid(levelGrid);
  57         renderCharacter(&playerCharacter, playerPos);
  58         glDisable(GL_TEXTURE_2D);
  59         glDisable(GL_LIGHT0);
  60
  61         glFlush();
  62         glutSwapBuffers();
  63         frameRendered();
  64         glutPostRedisplay();
  65 }
  66
  67 static void setupCamera() {
  68         glMatrixMode(GL_PROJECTION);
  69         glLoadIdentity();
  70         glOrtho(-16.0,
  71                 16.0,
  72                 -16.0/viewportAspectRatio,
  73                 16.0/viewportAspectRatio,
  74                 -128.0,
  75                 128.0);
  76         glRotatef(45.0f, 1.0f, 0.0f, 0.0f);
  77         glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
  78 }
  79
  80 static void moveCameraTo(const Vector3D pos) {
  81         glMatrixMode(GL_PROJECTION);
  82         glTranslatef(-pos.x, -pos.y, -pos.z);
  83 }
  84
  85 static void drawAxes() {
  86         glMatrixMode(GL_MODELVIEW);
  87         // X axis
  88         glColor3f(1.0f, 0.0f, 0.0f);
  89         glBegin(GL_LINES);
  90         glVertex3f(0.0f, 0.0f, 0.0f);
  91         glVertex3f(AXIS_RADIUS, 0.0f, 0.0f);
  92         glEnd();
  93         // Y axis
  94         glColor3f(0.0f, 1.0f, 0.0f);
  95         glBegin(GL_LINES);
  96         glVertex3f(0.0f, 0.0f, 0.0f);
  97         glVertex3f(0.0f, AXIS_RADIUS, 0.0f);
  98         glEnd();
  99         // Z axis
 100         glColor3f(0.0f, 0.0f, 1.0f);
 101         glBegin(GL_LINES);
 102         glVertex3f(0.0f, 0.0f, 0.0f);
 103         glVertex3f(0.0f, 0.0f, AXIS_RADIUS);
 104         glEnd();
 105 }
 106
 107 static void renderBlockGrid(const BlockGrid grid) {
 108         glMatrixMode(GL_MODELVIEW);
 109         for (int z = 0; z < grid.depth; ++z) {
 110                 glLoadIdentity();
 111                 glTranslatef(0.0f, 0.0f, z * BLOCKGRID_CELL_SIZE);
 112                 for (int x = 0; x < grid.width; ++x) {
 113                         drawAsset3D(getBlockFromGrid(grid, x, z)->asset3D);
 114                         glTranslatef(BLOCKGRID_CELL_SIZE, 0.0f, 0.0f);
 115                 }
 116         }
 117         glLoadIdentity();
 118 }
 119
 120 static void renderCharacter(const Character* character, const Vector3D pos) {
 121         glMatrixMode(GL_MODELVIEW);
 122         glTranslatef(pos.x, pos.y, pos.z);
 123         drawAsset3D(character->asset3D);
 124         glLoadIdentity();
 125 }
 126
 127 static void drawAsset3D(const Asset3D* asset3D) {
 128         if (asset3D == NULL) {
 129                 return;
 130         }
 131
 132         glMatrixMode(GL_MODELVIEW);
 133         glColor3f(0.5f, 1.0f, 0.0f);
 134
 135         for (size_t meshIndex = 0; meshIndex < asset3D->numMeshes; ++meshIndex) {
 136                 const Mesh mesh = asset3D->meshes[meshIndex];
 137                 glBindTexture(GL_TEXTURE_2D,
 138                               asset3D->materials[mesh.materialIndex].textureId);
 139                 bool hasNormals = mesh.normals != NULL;
 140                 bool hasTextureCoords = mesh.textureCoords != NULL;
 141
 142                 for (size_t faceIndex = 0; faceIndex < mesh.numFaces; ++faceIndex) {
 143                         const Face face = mesh.faces[faceIndex];
 144
 145                         GLenum faceMode;
 146                         switch (face.numIndices) {
 147                                 case 1: faceMode = GL_POINTS; break;
 148                                 case 2: faceMode = GL_LINES; break;
 149                                 case 3: faceMode = GL_TRIANGLES; break;
 150                                 default: faceMode = GL_POLYGON; break;
 151                         }
 152
 153                         glBegin(faceMode);
 154
 155                         for (size_t i = 0; i < face.numIndices; ++i) {
 156                                 unsigned int vertIndex = face.indices[i];
 157                                 if (hasNormals) {
 158                                         if (hasTextureCoords) {
 159                                                 Vector3D coords = mesh.textureCoords[vertIndex];
 160                                                 glTexCoord2f(coords.x, coords.y);
 161                                         }
 162                                         Vector3D normal = mesh.normals[vertIndex];
 163                                         glNormal3f(normal.x, normal.y, normal.z);
 164                                 }
 165                                 Vector3D vertex = mesh.vertices[vertIndex];
 166                                 glVertex3f(vertex.x, vertex.y, vertex.z);
 167                         }
 168
 169                         glEnd();
 170                 }
 171         }
 172         glBindTexture(GL_TEXTURE_2D, 0);
 173 }