#include #include #include #include //Command-line parsing #include "CLI11.hpp" //Image filtering and I/O #define STB_IMAGE_WRITE_IMPLEMENTATION #include //Global flag to silent verbose messages bool silent; typedef struct point { int x, y; } point_t; typedef struct bary_coord { float lambda_1, lambda_2, lambda_3; } bary_coord_t; typedef struct triangle { point_t p, q, r; } triangle_t; float maxf(float a, float b) { return a > b ? a : b; } void print_triangle(triangle_t t) { printf("(%d %d) (%d %d) (%d %d)", t.p.x, t.p.y, t.q.x, t.q.y, t.r.x, t.r.y); } int sig(int x) { return (x != 0) * (x > 0 ? 1 : -1); } int dist(point_t p, point_t q) { return sqrt((p.x-q.x)*(p.x-q.x) + (p.y-q.y)*(p.y-q.y)); } int determinant(point_t p, point_t q, point_t r) { int a, b, c, d; a = q.x-p.x; b = q.y-p.y; c = r.x-p.x; d = r.y-p.y; return a*d - b*c; } unsigned char isInside(point_t a, triangle_t t) { /* returns : 0 is not inside, 1 if inside, 2 if on edge */ int det_a1 = determinant(a, t.q, t.r); int det_a2 = determinant(a, t.p, t.q); int det_a3 = determinant(a, t.r, t.p); if ((sig(det_a1)==sig(det_a2)) && (sig(det_a1)==sig(det_a3))) { int dist_t1 = dist(t.q, t.r)*1.5; int dist_t2 = dist(t.p, t.q)*1.5; int dist_t3 = dist(t.r, t.p)*1.5; if ((dist_t1 > abs(det_a1)) || (dist_t2 > abs(det_a2)) || (dist_t3 > abs(det_a3))) return 2; return 1; }; return 0; } bary_coord_t bary_coord_of(point_t a, triangle_t t) { //TODO on peut juste faire des petites opérations sur les déterminant qu'on a déjà sinon point_t p = t.p; point_t q = t.q; point_t r = t.r; bary_coord_t bc; float qpx = (q.x - p.x); float rpy = (r.y - p.y); bc.lambda_3 = ((a.x-p.x)*(p.y-q.y)/(qpx*rpy) + (a.y-p.y)/rpy)/(1 - (p.x-r.x)/qpx*(p.y-q.y)/rpy); bc.lambda_2 = bc.lambda_3*(p.x - r.x)/qpx + (a.x - p.x)/qpx; bc.lambda_1 = 1 - (bc.lambda_2+bc.lambda_3); assert (bc.lambda_1 >= 0); return bc; } unsigned char pxColor(float lambda, unsigned char color, bool colored) { return colored ? (1 - lambda/4)*color : lambda*255; } int main(int argc, char **argv) { CLI::App app{"rasterizer"}; std::string outputImage= "output.png"; app.add_option("-o,--output", outputImage, "Output image")->required(); unsigned int nbTriangles = 5; app.add_option("-n,--ntriangles", nbTriangles, "Number of triangles (5)"); bool colored = false; app.add_flag("-c,--colored", colored, "Color triangles"); CLI11_PARSE(app, argc, argv); srand(time(0)); //Image loading int width=640,height=480, nbChannels=3; std::vector output(width*height*nbChannels); int* colors = (int*)malloc(sizeof(int)*3*nbTriangles); triangle_t* t = (triangle_t*)malloc(sizeof(triangle_t)*nbTriangles); for (auto i=0; i < nbTriangles; i++) { t[i] = { rand()%width, rand()%height, rand()%width, rand()%height, rand()%width, rand()%height }; colors[3*i] = rand()%255; colors[3*i+1] = rand()%255; colors[3*i+2] = rand()%255; //print_triangle(t[i]); //printf(" : (%d, %d, %d)\n", colors[3*i], colors[3*i+1], colors[3*i+2]); } for(auto i = 0 ; i < width ; ++i) { for(auto j = 0; j < height; ++j) { auto indexPixel = nbChannels*(width*j+i); output[indexPixel] = output[indexPixel+1] = output[indexPixel+2] = 0; for (auto triangle_id=0; triangle_id < nbTriangles; triangle_id++) { int valid = isInside({i, j}, t[triangle_id]); if (valid == 1) { bary_coord_t bc = bary_coord_of({i, j}, t[triangle_id]); output[ indexPixel ] = pxColor(bc.lambda_1, colors[3*triangle_id], colored); output[ indexPixel+1] = pxColor(bc.lambda_2, colors[3*triangle_id+1], colored); output[ indexPixel+2] = pxColor(bc.lambda_3, colors[3*triangle_id+2], colored); } else if (valid == 2) { output[indexPixel] = output[indexPixel+1] = output[indexPixel+2] = 255; } } } } //Final export std::cout<<"Exporting.."<