voxeltronik/src/graphics/chunkmesh.cpp

#include "graphics/chunkmesh.h"

#include "world.h"
#include "chunk.h"

#include <vector>
#include <GL/glew.h>
#include <GL/gl.h>
#include <iostream>


namespace vtk {

ChunkMesh::ChunkMesh(World& world, glm::ivec3 chunkPos) :
	mLinkedWorld(world),
	mLinkedChunkPos(chunkPos),
	mLocked(false)
{
	glGenBuffers(1, &mGeometryTexVBO);
	glGenBuffers(1, &mLightVBO);

	glGenVertexArrays(1, &mVAO);

	glBindVertexArray(mVAO);

	glBindBuffer(GL_ARRAY_BUFFER, mGeometryTexVBO);


	//vertices
	glVertexAttribPointer(0, 1, GL_UNSIGNED_INT, GL_FALSE, 0, NULL);
	glEnableVertexAttribArray(0);

	//tex uv coords
	//glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 4*sizeof(unsigned), (void*)(1*sizeof(unsigned)));
	//glEnableVertexAttribArray(1);
}

void ChunkMesh::rebuildChunkGeometry() {
	if (mLocked) return;
	mLocked = true;
	//get the chunk from position
	auto chunk = mLinkedWorld.getChunk(mLinkedChunkPos); 

	unsigned uTopModel [] = { 0,0,0,0,0,0 };
	//single vertex
	uTopModel[0] = (uTopModel[0] << 4) | unsigned(0);
	uTopModel[0] = (uTopModel[0] << 4) | unsigned(15);
	uTopModel[0] = (uTopModel[0] << 4) | unsigned(0);

	uTopModel[1] = (uTopModel[1] << 4) | unsigned(15);
	uTopModel[1] = (uTopModel[1] << 4) | unsigned(15);
	uTopModel[1] = (uTopModel[1] << 4) | unsigned(0);

	uTopModel[2] = (uTopModel[2] << 4) | unsigned(0);
	uTopModel[2] = (uTopModel[2] << 4) | unsigned(15);
	uTopModel[2] = (uTopModel[2] << 4) | unsigned(15);

	uTopModel[3] = (uTopModel[3] << 4) | unsigned(15);
	uTopModel[3] = (uTopModel[3] << 4) | unsigned(15);
	uTopModel[3] = (uTopModel[3] << 4) | unsigned(15);

	uTopModel[4] = (uTopModel[4] << 4) | unsigned(0);
	uTopModel[4] = (uTopModel[4] << 4) | unsigned(15);
	uTopModel[4] = (uTopModel[4] << 4) | unsigned(15);

	uTopModel[5] = (uTopModel[5] << 4) | unsigned(15);
	uTopModel[5] = (uTopModel[5] << 4) | unsigned(15);
	uTopModel[5] = (uTopModel[5] << 4) | unsigned(0);
	//unsigned((uTopModel[0] >> 8)&((1<<4)-1)); extract x, y ,z
	//unsigned((uTopModel[0] >> 4)&((1<<4)-1));
	//unsigned((uTopModel[0] >> 0)&((1<<4)-1));
	
	//temporary until I finish mesh providers
	float texUV [] = {
		0.0f, 1.0f,
		1.0f, 1.0f,
		0.0f, 0.0f,
		1.0f, 0.0f,
		0.0f, 0.0f,
		1.0f, 1.0f
	};
	float topModel [] = {
		//x     y     z    
		0.0f, 1.0f, 0.0f, //tl
		1.0f, 1.0f, 0.0f, //tr
		0.0f, 1.0f, 1.0f, //bl
		1.0f, 1.0f, 1.0f, //br
		0.0f, 1.0f, 1.0f, //bl
		1.0f, 1.0f, 0.0f //tr
	};
	float bottomModel [] = {
		//x     y     z     u     v
		0.0f, 0.0f, 1.0f, //tl
		1.0f, 0.0f, 1.0f, //tr
		0.0f, 0.0f, 0.0f, //bl
		1.0f, 0.0f, 0.0f, //br
		0.0f, 0.0f, 0.0f, //bl
		1.0f, 0.0f, 1.0f //tr
	};
	float northModel [] = {
		//x     y     z     u     v
		0.0f, 1.0f, 1.0f, //tl
		1.0f, 1.0f, 1.0f, //tr
		0.0f, 0.0f, 1.0f, //bl
		1.0f, 0.0f, 1.0f, //br
		0.0f, 0.0f, 1.0f, //bl
		1.0f, 1.0f, 1.0f //tr
	};
	float southModel [] = {
		//x     y     z     u     v
		1.0f, 1.0f, 0.0f, //tl
		0.0f, 1.0f, 0.0f, //tr
		1.0f, 0.0f, 0.0f, //bl
		0.0f, 0.0f, 0.0f, //br
		1.0f, 0.0f, 0.0f, //bl
		0.0f, 1.0f, 0.0f //tr
	};
	float eastModel [] = {
		//x     y     z     u     v
		1.0f, 1.0f, 1.0f, //tl
		1.0f, 1.0f, 0.0f, //tr
		1.0f, 0.0f, 1.0f, //bl
		1.0f, 0.0f, 0.0f, //br
		1.0f, 0.0f, 1.0f, //bl
		1.0f, 1.0f, 0.0f //tr
	};
	float westModel [] = {
		//x     y     z     u     v
		0.0f, 1.0f, 0.0f, //tl
		0.0f, 1.0f, 1.0f, //tr
		0.0f, 0.0f, 0.0f, //bl
		0.0f, 0.0f, 1.0f, //br
		0.0f, 0.0f, 0.0f, //bl
		0.0f, 1.0f, 1.0f //tr
	};

	// geometry format: x,y,z,u,v,i
	geometry.clear();
	mFaceCount = 0;
	int chunkSize = 16; // TODO: make this not hardcoded

	
	for (int i = 0; i < chunkSize; ++i) {
		for (int j = 0; j < chunkSize; ++j) {
			for (int k = 0; k < chunkSize; ++k) {
				if (chunk->isVoxelSolid(i,j,k)) {
					if (!chunk->isVoxelSolid(i,j+1,k)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							mGeometry.push_back(uTopModel[l]);
						}
					}
				}
			}
		}
	}
	/*	
	for (int i = 0; i < chunkSize; ++i) {
		for (int j = 0; j < chunkSize; ++j) {
			for (int k = 0; k < chunkSize; ++k) {
				//for each voxel in the chunk...
				// TODO: move this code into a mesh provider system

				//top
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i, j + 1, k)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(topModel[(l * 3)] + (float)i);
							geometry.push_back(topModel[(l * 3) + 1] + (float)j);
							geometry.push_back(topModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}

				//bottom
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i, j - 1, k)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(bottomModel[(l * 3)] + (float)i);
							geometry.push_back(bottomModel[(l * 3) + 1] + (float)j);
							geometry.push_back(bottomModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}

				//north
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i, j, k + 1)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(northModel[(l * 3)] + (float)i);
							geometry.push_back(northModel[(l * 3) + 1] + (float)j);
							geometry.push_back(northModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}
				//south
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i, j, k - 1)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(southModel[(l * 3)] + (float)i);
							geometry.push_back(southModel[(l * 3) + 1] + (float)j);
							geometry.push_back(southModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}
				//east
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i + 1, j, k)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(eastModel[(l * 3)] + (float)i);
							geometry.push_back(eastModel[(l * 3) + 1] + (float)j);
							geometry.push_back(eastModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}

				//west
				if (chunk->isVoxelSolid(i,j,k)) { //check that it's solid
					if (!chunk->isVoxelSolid(i - 1, j, k)) {
						++mFaceCount;
						for (int l = 0; l < 6; ++l) {
							geometry.push_back(westModel[(l * 3)] + (float)i);
							geometry.push_back(westModel[(l * 3) + 1] + (float)j);
							geometry.push_back(westModel[(l * 3) + 2] + (float)k);
							geometry.push_back(texUV[l*2]);
							geometry.push_back(texUV[(l*2)+1]);
							geometry.push_back(mLinkedWorld.voxelInfo.getTexIndexFromID(2, Face3D::TOP));
						}
					} 
				}
			}
		}
	}
	*/
	std::cout << mGeometry[1];
	mUpdated = true;
	mLocked = false;
}

void ChunkMesh::rebuildChunkLighting() {
	//this doesn't do anything yet
}

void ChunkMesh::draw() {
	if (mFaceCount > 0) {
		updateGeometry();
		glBindVertexArray(mVAO);
		glDrawArrays(GL_TRIANGLES, 0, mGeometryFaceCount * 6);
	}
}

bool ChunkMesh::updateGeometry() {
	if (mUpdated) {
		mUpdated = false;
		glBindBuffer(GL_ARRAY_BUFFER, mGeometryTexVBO);
		//glBufferData(GL_ARRAY_BUFFER, sizeof(float) * geometry.size(), geometry.data(), GL_STATIC_DRAW);
		glBufferData(GL_ARRAY_BUFFER, sizeof(float) * mGeometry.size(), mGeometry.data(), GL_STATIC_DRAW);
		mGeometryFaceCount = mFaceCount;
		return true;
	}
	return false;
}

} //namespace vtk