Use indexing to drastically reduce the number of vertices

cmake-build-emrelease/CMakeCache.txt

@@ -43,7 +43,7 @@ CMAKE_AR:FILEPATH=emar
 
 //Choose the type of build, options are: None Debug Release RelWithDebInfo
 // MinSizeRel ...
-CMAKE_BUILD_TYPE:STRING=Debug
+CMAKE_BUILD_TYPE:STRING=Release
 
 //Enable/Disable color output during build.
 CMAKE_COLOR_MAKEFILE:BOOL=ON

cmake-build-emrelease/CMakeFiles/FinalProject.dir/flags.make

@@ -6,5 +6,5 @@ CXX_DEFINES =
 
 CXX_INCLUDES = @CMakeFiles/FinalProject.dir/includes_CXX.rsp
 
-CXX_FLAGS = -g   -std=c++17 -std=gnu++17
+CXX_FLAGS = -O3 -DNDEBUG   -std=c++17 -std=gnu++17
 

cmake-build-emrelease/CMakeFiles/FinalProject.dir/link.txt

@@ -1 +1 @@
-/usr/bin/em++ -g -sMAX_WEBGL_VERSION=2 -s ASSERTIONS=1 -sUSE_GLFW=3 --preload-file 'assets' @CMakeFiles/FinalProject.dir/objects1 -o FinalProject.js @CMakeFiles/FinalProject.dir/linkLibs.rsp
+/usr/bin/em++ -O3 -DNDEBUG -sMAX_WEBGL_VERSION=2 -s ASSERTIONS=1 -sUSE_GLFW=3 --preload-file 'assets' @CMakeFiles/FinalProject.dir/objects1 -o FinalProject.js @CMakeFiles/FinalProject.dir/linkLibs.rsp

cmake-build-emrelease/CMakeFiles/FinalProject.dir/src/main.cpp.o.d

@@ -327,4 +327,5 @@ CMakeFiles/FinalProject.dir/src/main.cpp.o: \
   /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/render/camera.h \
   /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/world/chunk/world.h \
   /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/world/chunk/storage.h \
-  /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/world/chunk/typedefs.h
+  /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/world/chunk/typedefs.h \
+  /home/brett/Documents/Brock/CS\ 3P98/Final\ Project/include/world/registry.h

cmake-build-emrelease/cmake_install.cmake

@@ -12,7 +12,7 @@ if(NOT DEFINED CMAKE_INSTALL_CONFIG_NAME)
     string(REGEX REPLACE "^[^A-Za-z0-9_]+" ""
            CMAKE_INSTALL_CONFIG_NAME "${BUILD_TYPE}")
   else()
-    set(CMAKE_INSTALL_CONFIG_NAME "Debug")
+    set(CMAKE_INSTALL_CONFIG_NAME "Release")
   endif()
   message(STATUS "Install configuration: \"${CMAKE_INSTALL_CONFIG_NAME}\"")
 endif()

cmake-build-emrelease/libraries/BLT/CMakeFiles/BLT.dir/flags.make

@@ -6,5 +6,5 @@ CXX_DEFINES =
 
 CXX_INCLUDES = @CMakeFiles/BLT.dir/includes_CXX.rsp
 
-CXX_FLAGS = -g   -std=c++17 -std=gnu++17
+CXX_FLAGS = -O3 -DNDEBUG   -std=c++17 -std=gnu++17
 

cmake-build-emrelease/libraries/BLT/cmake_install.cmake

@@ -12,7 +12,7 @@ if(NOT DEFINED CMAKE_INSTALL_CONFIG_NAME)
     string(REGEX REPLACE "^[^A-Za-z0-9_]+" ""
            CMAKE_INSTALL_CONFIG_NAME "${BUILD_TYPE}")
   else()
-    set(CMAKE_INSTALL_CONFIG_NAME "Debug")
+    set(CMAKE_INSTALL_CONFIG_NAME "Release")
   endif()
   message(STATUS "Install configuration: \"${CMAKE_INSTALL_CONFIG_NAME}\"")
 endif()

include/world/chunk/storage.h

@@ -12,6 +12,7 @@
 #include "blt/std/logging.h"
 #include <world/chunk/typedefs.h>
 #include <world/registry.h>
+#include <unordered_map>
 
 // contains storage classes for block IDs inside chunks plus eventual lookup of block states
 
@@ -51,26 +52,24 @@ namespace fp {
     
     class mesh_storage {
         private:
-            std::vector<float> vertices;
+            std::unordered_map<vertex, unsigned int, _static::vertex_hash, _static::vertex_equality> created_vertices_index;
-            inline void add_and_translate(const float* array, const block_pos& pos) {
+            std::vector<vertex> vertices;
-                // since a chunk mesh contains all the faces for all the blocks inside the chunk
+            std::vector<unsigned int> indices;
-                // we can add the translated values of predefined "unit" faces. This is for the simple "fast" chunk mesh generator.
-                for (int i = 0; i < VTX_ARR_SIZE; i+=3){
-                    auto new_x = array[i] + (float)pos.x;
-                    auto new_y = array[i + 1] + (float)pos.y;
-                    auto new_z = array[i + 2] + (float)pos.z;
-//                    BLT_TRACE("Creating translated vertex {%f, %f, %f} from array position [%d, %d, %d]", new_x, new_y, new_z, i, i + 1, i + 2);
-                    vertices.push_back(new_x);
-                    vertices.push_back(new_y);
-                    vertices.push_back(new_z);
-                }
-            }
         public:
+            /**
+             * since a chunk mesh contains all the faces for all the blocks inside the chunk
+             * we can add the translated values of predefined "unit" faces. This is for the simple "fast" chunk mesh generator.
+             * @param face the direction the face is facing to be added to the mesh.
+             * @param pos position of the face
+             */
             void addFace(face face, const block_pos& pos);
             
-            inline std::vector<float>& getVertices() {
+            inline std::vector<vertex>& getVertices() {
                 return vertices;
             }
+            inline std::vector<unsigned int>& getIndices() {
+                return indices;
+            }
     };
     
     namespace mesh {

include/world/chunk/typedefs.h

@@ -11,7 +11,9 @@
 constexpr int CHUNK_SIZE = 32;
 const int CHUNK_SHIFT = (int)(log(CHUNK_SIZE) / log(2));
 // size that the base vertex arrays are assumed to be (per face)
-constexpr int VTX_ARR_SIZE = 18;
+constexpr int VTX_ARR_SIZE = 4;
+
+constexpr float EPSILON = 0.0001f;
 
 namespace fp {
     
@@ -52,6 +54,13 @@ namespace fp {
         block_pos(float x, float y, float z): block_pos(int(x), int(y), int(z)) {}
     };
     
+    // to ensure this is a POD we define the vertex as a C-struct. This allows us to store one large vertex array and pass that to the GPU
+    // instead of sending arrays for the positions, UVs, normals, etc.
+    // since OpenGL allows us to specify attributes based on offsets from the same VBO.
+    typedef struct {
+        float x, y, z;
+    } vertex;
+    
     namespace _static {
     
         // std::unordered_map requires a type. As a result the functions are encapsulated.
@@ -64,11 +73,29 @@ namespace fp {
             }
         };
     
+        struct vertex_hash {
+            inline size_t operator()(const vertex& pos) const {
+                size_t p1 = std::hash<float>()(pos.x);
+                size_t p2 = std::hash<float>()(pos.y);
+                size_t p3 = std::hash<float>()(pos.z);
+                return (p1 ^ (p2 << 1)) ^ p3;
+            }
+        };
+    
         struct chunk_pos_equality {
             inline bool operator()(const chunk_pos& p1, const chunk_pos& p2) const {
                 return p1.x == p2.x && p1.y == p2.y && p1.z == p2.z;
             }
         };
+    
+        struct vertex_equality {
+            inline bool operator()(const vertex& p1, const vertex& p2) const {
+                return p1.x >= p2.x - EPSILON && p1.x <= p2.x + EPSILON && p1.y >= p2.y - EPSILON && p1.y <= p2.y + EPSILON && p1.z >= p2.z - EPSILON && p1.z <= p2.z + EPSILON;
+            }
+//            inline bool operator()(const vertex& p1, const vertex& p2) const {
+//                return p1.x == p2.x && p1.y == p2.y && p1.z == p2.z;
+//            }
+        };
         
     }
 }

include/world/chunk/world.h

@@ -85,7 +85,8 @@ namespace fp {
                 
                 // since they both use the same amount of memory we will only store the vertices and draw with drawArrays, since it is less complex.
                 // set up the VBOs which will be later updated when the mesh is generated.
-                chunk_vao->bindVBO(new VBO(ARRAY_BUFFER, nullptr, 0), 0, 3);
+                chunk_vao->bindVBO(new VBO(ARRAY_BUFFER, nullptr, 0), 0, 3, GL_FLOAT, 3 * sizeof(float), 0);
+                chunk_vao->bindElementVBO(new VBO(ELEMENT_BUFFER, nullptr, 0));
             }
             
             ~chunk() {

src/main.cpp

@@ -45,8 +45,10 @@ int main() {
     chunk_shader = new fp::shader(shader_chunk_vert, shader_chunk_frag);
     world = new fp::world();
     
+    world->setBlock({0,0,0}, 1);
+    
     for (int i = 1; i < CHUNK_SIZE; i++)
-        for (int j = 0; j < 3; j++)
+        for (int j = 0; j < 2; j++)
             for (int k = 5; k < CHUNK_SIZE; k++)
                 world->setBlock({i,j,k}, 1);
     world->setBlock({-2, 2, 2}, 1);

src/world/chunk/storage.cpp

@@ -8,69 +8,55 @@
 
 constexpr float scale = 0.5f;
 
-const float x_positive_vertices[VTX_ARR_SIZE] = {
+const fp::vertex x_positive_vertices[VTX_ARR_SIZE] = {
-        // +x first triangle
+        {scale, scale,  scale},  // +x top right
-        scale, -scale,  scale,  // +x top left
+        {scale, scale,  -scale},  // +x bottom right
-        scale, scale, -scale,  // +x bottom right
+        {scale, -scale, -scale},  // +x bottom left
-        scale, scale,  scale,  // +x top right
+        {scale, -scale, scale}   // +x top left
-        // +x second triangle
-        scale, -scale,  scale,   // +x top left
-        scale, -scale, -scale,  // +x bottom left
-        scale, scale, -scale,  // +x bottom right
 };
-const float x_negative_vertices[VTX_ARR_SIZE] = {
+const fp::vertex x_negative_vertices[VTX_ARR_SIZE] = {
-        // -x first triangle
+        {-scale, scale,  scale},  // -x top right
-        -scale, scale,  scale,   // -x top right
+        {-scale, scale,  -scale},  // -x bottom right
-        -scale, scale, -scale,   // -x bottom right
+        {-scale, -scale, -scale},  // -x bottom left
-        -scale, -scale,  scale,  // -x top left
+        {-scale, -scale, scale}   // -x top left
-        // -x second triangle
-        -scale, scale, -scale,   // -x bottom right
-        -scale, -scale, -scale,  // -x bottom left
-        -scale, -scale,  scale,   // -x top left
 };
-const float y_positive_vertices[VTX_ARR_SIZE] = {
+const fp::vertex y_positive_vertices[VTX_ARR_SIZE] = {
-        // first triangle
+        {scale,  scale, scale},  // +y top right
-        scale, scale, -scale,   // top left
+        {-scale, scale, scale},  // +y bottom right
-        -scale, scale, scale,   // bottom right
+        {-scale, scale, -scale},  // +y bottom left
-        scale, scale, scale,    // top right
+        {scale,  scale, -scale},   // +y top left
-        // second triangle
-        scale, scale, -scale,   // top left
-        -scale, scale, -scale,  // bottom left
-        -scale, scale, scale,   // bottom right
 };
-const float y_negative_vertices[VTX_ARR_SIZE] = {
+const fp::vertex y_negative_vertices[VTX_ARR_SIZE] = {
-        // first triangle
+        {scale,  -scale, scale},  // -y top right
-        scale, -scale, scale,    // top right
+        {-scale, -scale, scale},  // -y bottom right
-        -scale, -scale, scale,   // bottom right
+        {-scale, -scale, -scale},  // -y bottom left
-        scale, -scale, -scale,   // top left
+        {scale,  -scale, -scale},    // -y top left
-        // second triangle
-        -scale, -scale, scale,   // bottom right
-        -scale, -scale, -scale,  // bottom left
-        scale, -scale, -scale,   // top left
 };
-const float z_positive_vertices[VTX_ARR_SIZE] = {
+const fp::vertex z_positive_vertices[VTX_ARR_SIZE] = {
-        // first triangle
+        {scale,  scale,  scale},  // +z top right
-        -scale,  scale, scale,  // top left
+        {scale,  -scale, scale},  // +z bottom right
-        scale, -scale, scale,  // bottom right
+        {-scale, -scale, scale},  // +z bottom left
-        scale,  scale, scale,  // top right
+        {-scale, scale,  scale},   // +z top left
-        // second triangle
-        -scale,  scale, scale,   // top left
-        -scale, -scale, scale,  // bottom left
-        scale, -scale, scale,  // bottom right
 };
-const float z_negative_vertices[VTX_ARR_SIZE] = {
+const fp::vertex z_negative_vertices[VTX_ARR_SIZE] = {
-        // first triangle
+        {scale,  scale,  -scale},  // -z top right
-        scale,  scale, -scale,  // top right
+        {scale,  -scale, -scale},  // -z bottom right
-        scale, -scale, -scale,  // bottom right
+        {-scale, -scale, -scale},  // -z bottom left
-        -scale,  scale, -scale,  // top left
+        {-scale, scale,  -scale},   // -z top left
-        // second triangle
+};
-        scale, -scale, -scale,  // bottom right
+
-        -scale, -scale, -scale,  // bottom left
+// indices are the same on all axis but are flipped between negative / positive as a result of back-face culling.
-        -scale,  scale, -scale,   // top left
+const std::vector<unsigned int> negative_indices = {
+        0, 1, 3,
+        1, 2, 3
+};
+const std::vector<unsigned int> positive_indices = {
+        3, 1, 0,
+        3, 2, 1
 };
 
 // always ordered the same as the enum!
-const float* face_decode[] = {
+const fp::vertex* face_decode[] = {
         x_positive_vertices,
         x_negative_vertices,
         y_positive_vertices,
@@ -80,5 +66,35 @@ const float* face_decode[] = {
 };
 
 void fp::mesh_storage::addFace(fp::face face, const block_pos& pos) {
-    add_and_translate(face_decode[face], pos);
+    const auto* face_vertices = face_decode[face];
+    // negatives are odd numbered, positives are even.
+    const auto& face_indices = face % 2 == 0 ? positive_indices : negative_indices;
+    
+    vertex translated_face_vertices[VTX_ARR_SIZE];
+    
+    // generate translated vertices
+    for (int i = 0; i < VTX_ARR_SIZE; i++) {
+        translated_face_vertices[i].x = face_vertices[i].x + (float) pos.x;
+        translated_face_vertices[i].y = face_vertices[i].y + (float) pos.y;
+        translated_face_vertices[i].z = face_vertices[i].z + (float) pos.z;
+    }
+    
+    for (unsigned int face_index : face_indices) {
+        // vertex associated with the index
+        auto index_vertex = translated_face_vertices[face_index];
+        // search to see if the vertex exists already inside the vertices face_vertices
+        auto find_existing_vertex = created_vertices_index.find(index_vertex);
+        if (find_existing_vertex == created_vertices_index.end()) {
+            // vertex doesn't already exist in the face_vertices.
+            // the current size contains the position we are inserting the vertex into. This is our index in the vertex face_vertices
+            auto current_index_pos = vertices.size();
+            vertices.push_back(index_vertex);
+            // Since we are inserting using the order of the face_indices this will ensure that the triangle vertices are ordered correctly (outward facing)
+            created_vertices_index.insert({index_vertex, current_index_pos});
+            indices.push_back(current_index_pos);
+        } else {
+            // does exist in the face_vertices we can use that knowledge to reduce the total # of vertices
+            indices.push_back(find_existing_vertex->second);
+        }
+    }
 }

src/world/chunk/world.cpp

@@ -9,9 +9,9 @@ void fp::world::generateFullMesh(mesh_storage* mesh, fp::chunk* chunk) {
     // checks to outside the bounds of the chunk should not have faces added. this will be handled by the partial mesh!
     bool outside = false;
     
-    for (int i = 1; i < CHUNK_SIZE - 1; i++) {
+    for (int i = 0; i < CHUNK_SIZE; i++) {
-        for (int j = 1; j < CHUNK_SIZE - 1; j++) {
+        for (int j = 0; j < CHUNK_SIZE; j++) {
-            for (int k = 1; k < CHUNK_SIZE - 1; k++) {
+            for (int k = 0; k < CHUNK_SIZE; k++) {
                 auto block = chunk->storage->get({i, j, k});
                 // opaque visibility is always 0. Non-zero values (true) are what we care about since opaque blocks are completely hidden
                 if (!fp::registry::get(block).visibility) {
@@ -46,7 +46,6 @@ inline void checkEdgeFaces(
 }
 
 void fp::world::generateEdgeMesh(mesh_storage* mesh, fp::chunk* chunk) {
-    BLT_TRACE("NOPE");
     // don't try to regen the chunk mesh unless there is a chance all neighbours are not null
     if (chunk->status != chunk_update_status::NEIGHBOUR_CREATE)
         return;
@@ -54,7 +53,6 @@ void fp::world::generateEdgeMesh(mesh_storage* mesh, fp::chunk* chunk) {
     chunk_neighbours neighbours{};
     getNeighbours(chunk->pos, neighbours);
     
-    BLT_TRACE("GOODBYE");
     
     // if none of the neighbours exist we cannot continue!
     for (auto* neighbour : neighbours.neighbours) {
@@ -75,8 +73,6 @@ void fp::world::generateEdgeMesh(mesh_storage* mesh, fp::chunk* chunk) {
         }
     }
     
-    BLT_TRACE("HELLO");
-    
     chunk->status = NONE;
     chunk->dirtiness = REFRESH;
 }
@@ -91,8 +87,6 @@ void fp::world::generateChunkMesh(fp::chunk* chunk) {
     if (chunk->dirtiness == PARTIAL_MESH) { // partial chunk mesh (had null neighbours)
         generateEdgeMesh(chunk->mesh, chunk);
     }
-    
-    chunk->dirtiness = REFRESH;
 }
 
 void fp::world::update() {
@@ -114,14 +108,18 @@ void fp::world::render(fp::shader& shader) {
         
         if (chunk->dirtiness == REFRESH) {
             auto& vertices = chunk->mesh->getVertices();
+            auto& indices = chunk->mesh->getIndices();
+            
+            // 11436 vert, 137,232 bytes
             
             BLT_INFO("Chunk [%d, %d, %d] mesh updated with %d vertices and %d indices taking (%d, %d) bytes!",
                      chunk->pos.x, chunk->pos.y, chunk->pos.z,
-                     vertices.size(), 0, vertices.size() * sizeof(float), 0 * sizeof(unsigned int));
+                     vertices.size(), indices.size(), vertices.size() * sizeof(vertex), indices.size() * sizeof(unsigned int));
             
             // upload the new vertices to the GPU
             chunk->chunk_vao->getVBO(0)->update(vertices);
-            chunk->render_size = vertices.size() / 3;
+            chunk->chunk_vao->getVBO(-1)->update(indices);
+            chunk->render_size = indices.size();
             
             // delete the memory from the CPU.
             delete (chunk->mesh);
@@ -135,7 +133,8 @@ void fp::world::render(fp::shader& shader) {
             shader.setMatrix("translation", translation);
             chunk->chunk_vao->bind();
             glEnableVertexAttribArray(0);
-            glDrawArrays(GL_TRIANGLES, 0, (int) chunk->render_size);
+            //glDrawArrays(GL_TRIANGLES, 0, (int) chunk->render_size);
+            glDrawElements(GL_TRIANGLES, (int)chunk->render_size, GL_UNSIGNED_INT, nullptr);
             glDisableVertexAttribArray(0);
         }
     }