render.c

   1 #include <GL/glut.h>
   2 #include <stdbool.h>
   3
   4 #include "assimp_types.h"
   5
   6 #include "level.h"
   7 #include "performance.h"
   8 #include "typedefs.h"
   9
  10 const float AXIS_RADIUS = 5.0f;
  11
  12 static void drawAxes();
  13 static void renderBlockGrid(const BlockGrid grid);
  14 static void drawBlock(const Block* block);
  15
  16
  17
  18 void initRender() {
  19         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  20
  21         GLfloat light0_ambient[] = {0.1f, 0.1f, 0.1f, 1.0f};
  22         GLfloat light0_diffuse[] = {1.0f, 1.0f, 1.0f, 1.0f};
  23         GLfloat light0_specular[] = {0.96f, 0.98f, 1.0f, 1.0f};
  24         GLfloat light0_position[] = {5.0f, 10.0f, 5.0f, 0.0f}; // (w == 0.0f) == directional
  25
  26         glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
  27         glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
  28         glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
  29         glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
  30
  31         glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 1.0f);
  32         glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, 0.05f);
  33         glLightf(GL_LIGHT0, GL_QUADRATIC_ATTENUATION, 0.005f);
  34 }
  35
  36 void renderScene() {
  37         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  38         glLoadIdentity();
  39
  40         glEnable(GL_NORMALIZE);
  41         glEnable(GL_CULL_FACE);
  42         glEnable(GL_DEPTH_TEST);
  43
  44         glDisable(GL_LIGHTING);
  45         drawAxes();
  46         glEnable(GL_LIGHTING);
  47
  48         glEnable(GL_LIGHT0);
  49         glEnable(GL_TEXTURE_2D);
  50         renderBlockGrid(levelGrid);
  51         glDisable(GL_TEXTURE_2D);
  52         glDisable(GL_LIGHT0);
  53
  54         glFlush();
  55         glutSwapBuffers();
  56         frameRendered();
  57         glutPostRedisplay();
  58 }
  59
  60 static void drawAxes() {
  61         point3f xAxisStart = { 0.0f, 0.0f, 0.0f };
  62         point3f xAxisEnd = { AXIS_RADIUS, 0.0f, 0.0f };
  63         point3f yAxisStart = { 0.0f, 0.0f, 0.0f };
  64         point3f yAxisEnd = { 0.0f, AXIS_RADIUS, 0.0f };
  65         point3f zAxisStart = { 0.0f, 0.0f, 0.0f };
  66         point3f zAxisEnd = { 0.0f, 0.0f, AXIS_RADIUS };
  67
  68         glColor3f(1.0f, 0.0f, 0.0f);
  69         glBegin(GL_LINES);
  70         glVertex3fv(xAxisStart);
  71         glVertex3fv(xAxisEnd);
  72         glEnd();
  73
  74         glColor3f(0.0f, 1.0f, 0.0f);
  75         glBegin(GL_LINES);
  76         glVertex3fv(yAxisStart);
  77         glVertex3fv(yAxisEnd);
  78         glEnd();
  79
  80         glColor3f(0.0f, 0.0f, 1.0f);
  81         glBegin(GL_LINES);
  82         glVertex3fv(zAxisStart);
  83         glVertex3fv(zAxisEnd);
  84         glEnd();
  85 }
  86
  87 static void renderBlockGrid(const BlockGrid grid) {
  88         glMatrixMode(GL_MODELVIEW);
  89         for (int z = 0; z < grid.depth; ++z) {
  90                 glLoadIdentity();
  91                 glTranslatef(0.0f, 0.0f, z * BLOCKGRID_CELL_SIZE);
  92                 for (int x = 0; x < grid.width; ++x) {
  93                         drawBlock(getBlockFromGrid(grid, x, z));
  94                         glTranslatef(BLOCKGRID_CELL_SIZE, 0.0f, 0.0f);
  95                 }
  96         }
  97         glLoadIdentity();
  98 }
  99
 100 static void drawBlock(const Block* block) {
 101         if (block->sceneData == NULL) {
 102                 return;
 103         }
 104
 105         glColor3f(0.5f, 1.0f, 0.0f);
 106
 107         for (int i = 0; i < block->sceneData->mNumMeshes; ++i) {
 108                 glBindTexture(GL_TEXTURE_2D, block->textureIds[i]);
 109                 const AiMesh* mesh = block->sceneData->mMeshes[i];
 110                 bool hasNormals = mesh->mNormals != NULL;
 111                 bool hasTextureCoords = mesh->mTextureCoords[0] != NULL;
 112
 113                 for (int k = 0; k < mesh->mNumFaces; ++k) {
 114                         const AiFace face = mesh->mFaces[k];
 115
 116                         GLenum faceMode;
 117                         switch (face.mNumIndices) {
 118                                 case 1: faceMode = GL_POINTS; break;
 119                                 case 2: faceMode = GL_LINES; break;
 120                                 case 3: faceMode = GL_TRIANGLES; break;
 121                                 default: faceMode = GL_POLYGON; break;
 122                         }
 123
 124                         glBegin(faceMode);
 125
 126                         for (int l = 0; l < face.mNumIndices; ++l) {
 127                                 unsigned int vertexIndex = face.mIndices[l];
 128                                 if (hasNormals) {
 129                                         if (hasTextureCoords) {
 130                                                 AiVector3D coords = mesh->mTextureCoords[0][vertexIndex];
 131                                                 glTexCoord2f(coords.x, coords.y);
 132                                         }
 133                                         glNormal3fv(&mesh->mNormals[vertexIndex].x);
 134                                 }
 135                                 glVertex3fv((const GLfloat*) &mesh->mVertices[vertexIndex]);
 136                         }
 137
 138                         glEnd();
 139                 }
 140         }
 141         glBindTexture(GL_TEXTURE_2D, 0);
 142 }