render.c

   1 #include <GL/glut.h>
   2 #include <stdbool.h>
   3
   4 #include "level.h"
   5 #include "performance.h"
   6 #include "typedefs.h"
   7
   8 const float AXIS_RADIUS = 5.0f;
   9
  10 static void drawAxes();
  11 static void renderBlockGrid(const BlockGrid grid);
  12 static void drawBlock(const Block* block);
  13
  14
  15
  16 void initRender() {
  17         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  18
  19         GLfloat light0_ambient[] = {0.1f, 0.1f, 0.1f, 1.0f};
  20         GLfloat light0_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f};
  21         GLfloat light0_specular[] = {0.96f, 0.98f, 1.0f, 1.0f};
  22         GLfloat light0_position[] = {5.0f, 10.0f, 5.0f, 0.0f}; // (w == 0.0f) == directional
  23
  24         glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
  25         glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
  26         glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
  27         glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
  28
  29         glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 1.0f);
  30         glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 0.05f);
  31         glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.005f);
  32 }
  33
  34 void renderScene() {
  35         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  36         glLoadIdentity();
  37
  38         glEnable(GL_NORMALIZE);
  39         glEnable(GL_CULL_FACE);
  40         glEnable(GL_DEPTH_TEST);
  41
  42         glDisable(GL_LIGHTING);
  43         drawAxes();
  44         glEnable(GL_LIGHTING);
  45
  46         glEnable(GL_LIGHT0);
  47         glEnable(GL_TEXTURE_2D);
  48         renderBlockGrid(levelGrid);
  49         glDisable(GL_TEXTURE_2D);
  50         glDisable(GL_LIGHT0);
  51
  52         glFlush();
  53         glutSwapBuffers();
  54         frameRendered();
  55         glutPostRedisplay();
  56 }
  57
  58 static void drawAxes() {
  59         // X axis
  60         glColor3f(1.0f, 0.0f, 0.0f);
  61         glBegin(GL_LINES);
  62         glVertex3f(0.0f, 0.0f, 0.0f);
  63         glVertex3f(AXIS_RADIUS, 0.0f, 0.0f);
  64         glEnd();
  65         // Y axis
  66         glColor3f(0.0f, 1.0f, 0.0f);
  67         glBegin(GL_LINES);
  68         glVertex3f(0.0f, 0.0f, 0.0f);
  69         glVertex3f(0.0f, AXIS_RADIUS, 0.0f);
  70         glEnd();
  71         // Z axis
  72         glColor3f(0.0f, 0.0f, 1.0f);
  73         glBegin(GL_LINES);
  74         glVertex3f(0.0f, 0.0f, 0.0f);
  75         glVertex3f(0.0f, 0.0f, AXIS_RADIUS);
  76         glEnd();
  77 }
  78
  79 static void renderBlockGrid(const BlockGrid grid) {
  80         glMatrixMode(GL_MODELVIEW);
  81         for (int z = 0; z < grid.depth; ++z) {
  82                 glLoadIdentity();
  83                 glTranslatef(0.0f, 0.0f, z * BLOCKGRID_CELL_SIZE);
  84                 for (int x = 0; x < grid.width; ++x) {
  85                         drawBlock(getBlockFromGrid(grid, x, z));
  86                         glTranslatef(BLOCKGRID_CELL_SIZE, 0.0f, 0.0f);
  87                 }
  88         }
  89         glLoadIdentity();
  90 }
  91
  92 static void drawBlock(const Block* block) {
  93         if (block->asset3D == NULL) {
  94                 return;
  95         }
  96
  97         glColor3f(0.5f, 1.0f, 0.0f);
  98
  99         const Asset3D* asset3D = block->asset3D;
 100         for (int meshIndex = 0; meshIndex < asset3D->numMeshes; ++meshIndex) {
 101                 const Mesh mesh = asset3D->meshes[meshIndex];
 102                 glBindTexture(GL_TEXTURE_2D,
 103                               asset3D->materials[mesh.materialIndex].textureId);
 104                 bool hasNormals = mesh.normals != NULL;
 105                 bool hasTextureCoords = mesh.textureCoords != NULL;
 106
 107                 for (int faceIndex = 0; faceIndex < mesh.numFaces; ++faceIndex) {
 108                         const Face face = mesh.faces[faceIndex];
 109
 110                         GLenum faceMode;
 111                         switch (face.numIndices) {
 112                                 case 1: faceMode = GL_POINTS; break;
 113                                 case 2: faceMode = GL_LINES; break;
 114                                 case 3: faceMode = GL_TRIANGLES; break;
 115                                 default: faceMode = GL_POLYGON; break;
 116                         }
 117
 118                         glBegin(faceMode);
 119
 120                         for (int i = 0; i < face.numIndices; ++i) {
 121                                 unsigned int vertIndex = face.indices[i];
 122                                 if (hasNormals) {
 123                                         if (hasTextureCoords) {
 124                                                 Vector3D coords = mesh.textureCoords[vertIndex];
 125                                                 glTexCoord2f(coords.x, coords.y);
 126                                         }
 127                                         Vector3D normal = mesh.normals[vertIndex];
 128                                         glNormal3f(normal.x, normal.y, normal.z);
 129                                 }
 130                                 Vector3D vertex = mesh.vertices[vertIndex];
 131                                 glVertex3f(vertex.x, vertex.y, vertex.z);
 132                         }
 133
 134                         glEnd();
 135                 }
 136         }
 137         glBindTexture(GL_TEXTURE_2D, 0);
 138 }