MeshData.cpp

//
//  MeshData.cpp
//  Curvature
//
//  Created by Simon Demeule on 2020-05-05.
//  Copyright © 2020 Simon Demeule. All rights reserved.
//

#include "MeshData.hpp"

#include <glm/glm.hpp>
#include <cstring>
#include <vector>
#include <string>

MeshData::MeshData(std::string filePath) {
        FILE *file = fopen(filePath.c_str(), "r");
        if (file == NULL) {
            printf("Unable to open the file ! Are you in the right path ?\n");
            getchar();
            return;
        }
        
        while(1){
            
            char lineHeader[128];
            // read the first word of the line
            int res = fscanf(file, "%s", lineHeader,128);
            if (res == EOF)
                break; // EOF = End Of File. Quit the loop.
            
            // else : parse lineHeader
            
            if (strcmp(lineHeader, "v") == 0){
                glm::vec3 vertex;
                fscanf(file, "%f %f %f\n", &vertex.x, &vertex.y, &vertex.z);
                vertexData.push_back(vertex);
            }
            else if (strcmp(lineHeader, "vt") == 0){
                glm::vec2 uv;
                fscanf(file, "%f %f\n", &uv.x, &uv.y);
                uv.y = -uv.y; // Invert V coordinate since we will only use DDS texture, which are inverted. Remove if you want to use TGA or BMP loaders.
                uvData.push_back(uv);
            }
            else if (strcmp(lineHeader, "vn") == 0){
                glm::vec3 normal;
                fscanf(file, "%f %f %f\n", &normal.x, &normal.y, &normal.z);
                normalData.push_back(normal);
            }
            else if (strcmp(lineHeader, "f") == 0){
                int vertexIndex[3], uvIndex[3], normalIndex[3];
                bool uv = true;
                bool norm = true;
                char line [128];
                fgets(line, 128, file);
                // vertex, uv, norm
                int matches = sscanf(line, "%d/%d/%d %d/%d/%d %d/%d/%d\n", &vertexIndex[0], &uvIndex[0], &normalIndex[0], &vertexIndex[1], &uvIndex[1], &normalIndex[1], &vertexIndex[2], &uvIndex[2], &normalIndex[2]);
                if (matches != 9){
                    // vertex, norm
                    matches = sscanf(line, "%d//%d %d//%d %d//%d\n", &vertexIndex[0], &normalIndex[0], &vertexIndex[1], &normalIndex[1], &vertexIndex[2], &normalIndex[2]);
                    if (matches != 6){
                        // vertex, uv
                        matches = sscanf(line, "%d/%d %d/%d %d/%d\n", &vertexIndex[0], &uvIndex[0], &vertexIndex[1], &uvIndex[1], &vertexIndex[2], &uvIndex[2]);
                        if (matches != 6){
                            // vertex
                            matches = sscanf(line, "%d %d %d\n", &vertexIndex[0], &vertexIndex[1], &vertexIndex[2]);
                            if (matches != 6){
                                printf("File can't be read by this simple parser. 'f' format expected: d/d/d d/d/d d/d/d || d/d d/d d/d || d//d d//d d//d\n");
                                printf("Character at %d", ftell(file));
                                return;
                            }
                            uv, norm = false;
                        } else {
                            norm;
                        }
                    }else{
                        uv = false;
                    }
                }
                vertexIndices.push_back(abs(vertexIndex[0]) - 1);
                vertexIndices.push_back(abs(vertexIndex[1]) - 1);
                vertexIndices.push_back(abs(vertexIndex[2]) - 1);
                if(norm){
                    normalIndices.push_back(abs(normalIndex[0]) - 1);
                    normalIndices.push_back(abs(normalIndex[1]) - 1);
                    normalIndices.push_back(abs(normalIndex[2]) - 1);
                }
                if(uv){
                    uvIndices.push_back(abs(uvIndex[0]) - 1);
                    uvIndices.push_back(abs(uvIndex[1]) - 1);
                    uvIndices.push_back(abs(uvIndex[2]) - 1);
                }
            }
            else{
                char clear[1000];
                fgets(clear, 1000, file);
            }
        }
}