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Merged
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Jan 23, 2025
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Add smallpt as an example notebook #235

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1 change: 1 addition & 0 deletions .github/workflows/deploy-github-page.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -72,6 +72,7 @@ jobs:
--XeusAddon.prefix=${{ env.PREFIX }} \
--contents README.md \
--contents notebooks/xeus-cpp-lite-demo.ipynb \
--contents notebooks/smallpt.ipynb \
--contents notebooks/images/marie.png \
--contents notebooks/audio/audio.wav \
--output-dir dist
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3 changes: 2 additions & 1 deletion CMakeLists.txt
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Expand Up @@ -445,8 +445,9 @@ if(EMSCRIPTEN)
# TODO: Remove the exported runtime methods
# after the next xeus release.
target_link_options(xcpp
PUBLIC "SHELL: -s USE_SDL=2"
PUBLIC "SHELL: -s EXPORTED_RUNTIME_METHODS='[\"FS\",\"PATH\",\"LDSO\",\"loadDynamicLibrary\",\"ERRNO_CODES\"]'"
PUBLIC "SHELL: --preload-file ${SYSROOT_PATH}/include@/include"
PUBLIC "SHELL: --preload-file ${SYSROOT_PATH}/@/"
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oops, I think I had messed up a tad bit here (I just realized this)

Hey @vgvassilev ,

If you remember we had attempted to add the example notebook for smallpt in our codebase. And then I had made a commit to revert this patch #236

The reason for the revert was this

  1. As you see I moved a level above sysroot/include here to just sysroot. So obviously we were preloading much more than we wanted in our file system. So our builds had this warning
warning: file packager is creating an asset bundle of 582 MB. this is very large, and browsers might have trouble loading it. see https://hacks.mozilla.org/2015/02/synchronous-execution-and-filesystem-access-in-emscripten/
  1. So though stuff was running locally pretty smoothly .... our deployment was having trouble loading the xcpp.data file which turned out to be huge as the warning said.

Hence the revert.

What I just realized is all SDL headers also lie inside the sysroot/include location (not sure if this was changed as we shifted to emscripten 3.1.73 or so)

(base) anutosh491@Anutoshs-MacBook-Air SDL % pwd
/Users/anutosh491/work/emsdk/upstream/emscripten/cache/sysroot/include/SDL
(base) anutosh491@Anutoshs-MacBook-Air SDL % ls
COPYING                 SDL_config.h            SDL_config_pandora.h    SDL_gesture.h           SDL_keycode.h           SDL_opengl.h            SDL_render.h            SDL_syswm.h             begin_code.h
SDL.h                   SDL_config.h.in         SDL_config_windows.h    SDL_gfxPrimitives.h     SDL_loadso.h            SDL_opengles.h          SDL_revision.h          SDL_thread.h            close_code.h
SDL_assert.h            SDL_config_android.h    SDL_config_wiz.h        SDL_haptic.h            SDL_log.h               SDL_opengles2.h         SDL_rotozoom.h          SDL_timer.h
SDL_atomic.h            SDL_config_emscripten.h SDL_copying.h           SDL_hints.h             SDL_main.h              SDL_pixels.h            SDL_rwops.h             SDL_touch.h
SDL_audio.h             SDL_config_iphoneos.h   SDL_cpuinfo.h           SDL_image.h             SDL_mixer.h             SDL_platform.h          SDL_scancode.h          SDL_ttf.h
SDL_blendmode.h         SDL_config_macosx.h     SDL_endian.h            SDL_input.h             SDL_mouse.h             SDL_power.h             SDL_shape.h             SDL_types.h
SDL_clipboard.h         SDL_config_minimal.h    SDL_error.h             SDL_joystick.h          SDL_mutex.h             SDL_quit.h              SDL_stdinc.h            SDL_version.h
SDL_compat.h            SDL_config_nintendods.h SDL_events.h            SDL_keyboard.h          SDL_name.h              SDL_rect.h              SDL_surface.h           SDL_video.h

Which means are already having access to the SDL header right now. We don't need to change nothing with preloading and we should definitely be able to add this example !

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#299

PUBLIC "SHELL: --post-js ${CMAKE_CURRENT_SOURCE_DIR}/wasm_patches/post.js"
)
# TODO: Emscripten supports preloading files just once before it generates
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359 changes: 359 additions & 0 deletions notebooks/smallpt.ipynb
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@@ -0,0 +1,359 @@
{
"cells": [
{
"cell_type": "code",
"execution_count": 1,
"id": "72cd5c0c-3a52-43a5-a714-0baee1f7464c",
"metadata": {
"trusted": true,
"vscode": {
"languageId": "c++"
}
},
"outputs": [],
"source": [
"// Adapted from smallpt, a Path Tracer by Kevin Beason, 2008\n",
"#include <math.h>\n",
"#include <stdlib.h>\n",
"#include <vector>\n",
"\n",
"struct Vec {\n",
" double x, y, z; // position, also color (r,g,b)\n",
" Vec(double x_ = 0, double y_ = 0, double z_ = 0) {\n",
" x = x_;\n",
" y = y_;\n",
" z = z_;\n",
" }\n",
" Vec operator+(const Vec &b) const { return Vec(x + b.x, y + b.y, z + b.z); }\n",
" Vec operator-(const Vec &b) const { return Vec(x - b.x, y - b.y, z - b.z); }\n",
" Vec operator*(double b) const { return Vec(x * b, y * b, z * b); }\n",
" Vec mult(const Vec &b) const { return Vec(x * b.x, y * b.y, z * b.z); }\n",
" Vec &norm() { return *this = *this * (1 / sqrt(x * x + y * y + z * z)); }\n",
" double dot(const Vec &b) const { return x * b.x + y * b.y + z * b.z; }\n",
" Vec operator%(Vec &b) { // cross\n",
" return Vec(y * b.z - z * b.y, z * b.x - x * b.z, x * b.y - y * b.x);\n",
" }\n",
"};\n",
"struct Ray {\n",
" Vec o, d;\n",
" Ray(Vec o_, Vec d_) : o(o_), d(d_) {}\n",
"};\n",
"enum Refl_t { DIFF, SPEC, REFR }; // material types, used in radiance()\n",
"struct Sphere {\n",
" double rad; // radius\n",
" Vec p, e, c; // position, emission, color\n",
" Refl_t refl; // reflection type (DIFFuse, SPECular, REFRactive)\n",
" Sphere(double rad_, Vec p_, Vec e_, Vec c_, Refl_t refl_)\n",
" : rad(rad_), p(p_), e(e_), c(c_), refl(refl_) {}\n",
" double intersect(const Ray &r) const { // returns distance, 0 if nohit\n",
" Vec op = p - r.o; // Solve t^2*d.d + 2*t*(o-p).d + (o-p).(o-p)-R^2 = 0\n",
" double t, eps = 1e-4, b = op.dot(r.d), det = b * b - op.dot(op) + rad * rad;\n",
" if (det < 0)\n",
" return 0;\n",
" else\n",
" det = sqrt(det);\n",
" return (t = b - det) > eps ? t : ((t = b + det) > eps ? t : 0);\n",
" }\n",
"};"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "acc1ec30-5f0a-446f-a066-3dc3369ed39e",
"metadata": {
"trusted": true,
"vscode": {
"languageId": "c++"
}
},
"outputs": [],
"source": [
"std::vector<Sphere> spheres = {\n",
" // Scene: radius, position, emission, color, material\n",
" Sphere(1e5, Vec(1e5 + 1, 40.8, 81.6), Vec(), Vec(.75, .25, .25),\n",
" DIFF), // Left\n",
" Sphere(1e5, Vec(-1e5 + 99, 40.8, 81.6), Vec(), Vec(.25, .25, .75),\n",
" DIFF), // Rght\n",
" Sphere(1e5, Vec(50, 40.8, 1e5), Vec(), Vec(.75, .75, .75), DIFF), // Back\n",
" Sphere(1e5, Vec(50, 40.8, -1e5 + 170), Vec(), Vec(), DIFF), // Frnt\n",
" Sphere(1e5, Vec(50, 1e5, 81.6), Vec(), Vec(.75, .75, .75), DIFF), // Botm\n",
" Sphere(1e5, Vec(50, -1e5 + 81.6, 81.6), Vec(), Vec(.75, .75, .75),\n",
" DIFF), // Top\n",
" Sphere(16.5, Vec(27, 16.5, 47), Vec(), Vec(1, 1, 1) * .999, SPEC), // Mirr\n",
" Sphere(16.5, Vec(73, 16.5, 78), Vec(), Vec(1, 1, 1) * .999, REFR), // Glas\n",
" Sphere(600, Vec(50, 681.6 - .27, 81.6), Vec(12, 12, 12), Vec(),\n",
" DIFF) // Lite\n",
"};\n",
"\n",
"inline double clamp(double x) { return x < 0 ? 0 : x > 1 ? 1 : x; }\n",
"inline int toInt(double x) { return int(pow(clamp(x), 1 / 2.2) * 255 + .5); }\n",
"inline bool intersect(const Ray &r, double &t, int &id) {\n",
" double n = spheres.size(), d, inf = t = 1e20;\n",
" for (int i = int(n); i--;)\n",
" if ((d = spheres[i].intersect(r)) && d < t) {\n",
" t = d;\n",
" id = i;\n",
" }\n",
" return t < inf;\n",
"}\n"
]
},
{
"cell_type": "code",
"execution_count": 3,
"id": "cf0fd047-c5da-4606-aeae-4358d2064f10",
"metadata": {
"trusted": true,
"vscode": {
"languageId": "c++"
}
},
"outputs": [],
"source": [
"Vec radiance(const Ray &r, int depth, unsigned short *Xi) {\n",
" double t; // distance to intersection\n",
" int id = 0; // id of intersected object\n",
" if (!intersect(r, t, id))\n",
" return Vec(); // if miss, return black\n",
" const Sphere &obj = spheres[id]; // the hit object\n",
" Vec x = r.o + r.d * t, n = (x - obj.p).norm(),\n",
" nl = n.dot(r.d) < 0 ? n : n * -1, f = obj.c;\n",
" double p = f.x > f.y && f.x > f.z ? f.x : f.y > f.z ? f.y : f.z; // max refl\n",
" if (++depth > 5) {\n",
" if (erand48(Xi) < p) {\n",
" f = f * (1 / p);\n",
" } else {\n",
" return obj.e; // R.R.\n",
" }\n",
" }\n",
" if (obj.refl == DIFF) { // Ideal DIFFUSE reflection\n",
" double r1 = 2 * M_PI * erand48(Xi), r2 = erand48(Xi), r2s = sqrt(r2);\n",
" Vec w = nl, u = ((fabs(w.x) > .1 ? Vec(0, 1) : Vec(1)) % w).norm(),\n",
" v = w % u;\n",
" Vec d = (u * cos(r1) * r2s + v * sin(r1) * r2s + w * sqrt(1 - r2)).norm();\n",
" return obj.e + f.mult(radiance(Ray(x, d), depth, Xi));\n",
" } else if (obj.refl == SPEC) // Ideal SPECULAR reflection\n",
" return obj.e +\n",
" f.mult(radiance(Ray(x, r.d - n * 2 * n.dot(r.d)), depth, Xi));\n",
" Ray reflRay(x, r.d - n * 2 * n.dot(r.d)); // Ideal dielectric REFRACTION\n",
" bool into = n.dot(nl) > 0; // Ray from outside going in?\n",
" double nc = 1, nt = 1.5, nnt = into ? nc / nt : nt / nc, ddn = r.d.dot(nl),\n",
" cos2t;\n",
" if ((cos2t = 1 - nnt * nnt * (1 - ddn * ddn)) <\n",
" 0) // Total internal reflection\n",
" return obj.e + f.mult(radiance(reflRay, depth, Xi));\n",
" Vec tdir =\n",
" (r.d * nnt - n * ((into ? 1 : -1) * (ddn * nnt + sqrt(cos2t)))).norm();\n",
" double a = nt - nc, b = nt + nc, R0 = a * a / (b * b),\n",
" c = 1 - (into ? -ddn : tdir.dot(n));\n",
" double Re = R0 + (1 - R0) * c * c * c * c * c, Tr = 1 - Re, P = .25 + .5 * Re,\n",
" RP = Re / P, TP = Tr / (1 - P);\n",
" return obj.e +\n",
" f.mult(depth > 2\n",
" ? (erand48(Xi) < P ? // Russian roulette\n",
" radiance(reflRay, depth, Xi) * RP\n",
" : radiance(Ray(x, tdir), depth, Xi) * TP)\n",
" : radiance(reflRay, depth, Xi) * Re +\n",
" radiance(Ray(x, tdir), depth, Xi) * Tr);\n",
"}"
]
},
{
"cell_type": "code",
"execution_count": 4,
"id": "70a01b15-3b76-4008-b674-0cc05b0342dd",
"metadata": {
"trusted": true,
"vscode": {
"languageId": "c++"
}
},
"outputs": [],
"source": [
"#include <SDL2/SDL.h>\n",
"#include <string>\n",
"#include <fstream>\n",
"#include <sstream>\n",
"#include <iostream>\n",
"#include \"nlohmann/json.hpp\"\n",
"#include \"xeus/xbase64.hpp\"\n",
"#include \"xcpp/xdisplay.hpp\"\n",
"\n",
"namespace nl = nlohmann;\n",
"\n",
"namespace im\n",
"{\n",
" struct image\n",
" { \n",
" inline image(const std::string& filename)\n",
" {\n",
" std::ifstream fin(filename, std::ios::binary); \n",
" m_buffer << fin.rdbuf();\n",
" }\n",
" \n",
" std::stringstream m_buffer;\n",
" };\n",
" \n",
" nl::json mime_bundle_repr(const image& i)\n",
" {\n",
" auto bundle = nl::json::object();\n",
" bundle[\"image/bmp\"] = xeus::base64encode(i.m_buffer.str());\n",
" return bundle;\n",
" }\n",
"}\n",
"\n",
"// Function to save SDL surface as BMP persistently\n",
"void save_bmp_to_filesystem(SDL_Surface* surface, const std::string& filename)\n",
"{\n",
" if (surface)\n",
" {\n",
" if (SDL_SaveBMP(surface, filename.c_str()) == 0)\n",
" {\n",
" std::cout << \"[DEBUG] Surface saved to \" << filename << std::endl;\n",
" }\n",
" else\n",
" {\n",
" std::cerr << \"[ERROR] Failed to save BMP to \" << filename << \": \" << SDL_GetError() << std::endl;\n",
" }\n",
" }\n",
" else\n",
" {\n",
" std::cerr << \"[ERROR] Surface is null, cannot save BMP.\" << std::endl;\n",
" }\n",
"}\n",
"\n",
"// Function to encode an SDL surface and render it in Jupyter\n",
"void render_sdl_surface_to_jupyter(SDL_Surface* surface, const std::string& filename)\n",
"{\n",
"\n",
" if (!surface)\n",
" {\n",
" std::cerr << \"[ERROR] Surface is null\" << std::endl;\n",
" return;\n",
" }\n",
"\n",
" std::cout << \"[DEBUG] Surface created successfully\" << std::endl;\n",
"\n",
" im::image output(filename);\n",
" xcpp::display(output);\n",
" \n",
" // Cleanup\n",
" SDL_FreeSurface(surface);\n",
" std::cout << \"[DEBUG] Surface freed\" << std::endl;\n",
" remove(filename.c_str());\n",
"}"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2fd6e42b-6e84-46e5-9197-0e0c2e054ad1",
"metadata": {
"trusted": true,
"vscode": {
"languageId": "c++"
}
},
"outputs": [],
"source": [
"int main() {\n",
" // Debug: Initialization\n",
" std::cout << \"[DEBUG] Initializing SDL\" << std::endl;\n",
"\n",
" if (SDL_Init(SDL_INIT_EVENTS) != 0) {\n",
" std::cerr << \"[ERROR] SDL_Init failed: \" << SDL_GetError() << std::endl;\n",
" return 1;\n",
" }\n",
" std::cout << \"[DEBUG] SDL initialized successfully\" << std::endl;\n",
"\n",
" // Define width, height, and samples\n",
" int w = 320, h = 240, samps = 16; // # samples\n",
" std::cout << \"[DEBUG] Dimensions: \" << w << \"x\" << h << \", Samples: \" << samps << std::endl;\n",
"\n",
" // Create an off-screen surface\n",
" SDL_Surface* surface = SDL_CreateRGBSurfaceWithFormat(0, w, h, 32, SDL_PIXELFORMAT_RGBA32);\n",
" if (!surface) {\n",
" std::cerr << \"[ERROR] Failed to create SDL surface: \" << SDL_GetError() << std::endl;\n",
" SDL_Quit();\n",
" return 1;\n",
" }\n",
" std::cout << \"[DEBUG] SDL surface created successfully\" << std::endl;\n",
"\n",
" // Prepare the camera and pixel buffer\n",
" Ray cam(Vec(50, 52, 295.6), Vec(0, -0.042612, -1).norm()); // cam pos, dir\n",
" Vec cx = Vec(w * .5135 / h), cy = (cx % cam.d).norm() * .5135, r,\n",
" *c = new Vec[w * h];\n",
"\n",
" std::cout << \"[DEBUG] The image should be on your screen soon\" << std::endl;\n",
" // Render the scene\n",
" for (int y = 0; y < h; y++) { // Loop over image rows\n",
" unsigned short x, Xi[3] = {0, 0, static_cast<unsigned short>(y * y * y)};\n",
" for (x = 0; x < w; x++) { // Loop cols\n",
" int sy, i = (h - y - 1) * w + x;\n",
" for (sy = 0; sy < 2; sy++) { // 2x2 subpixel rows\n",
" int sx;\n",
" for (sx = 0; sx < 2; sx++, r = Vec()) { // 2x2 subpixel cols\n",
" for (int s = 0; s < samps; s++) { // Subpixel sampling\n",
" double r1 = 2 * erand48(Xi),\n",
" dx = r1 < 1 ? sqrt(r1) - 1 : 1 - sqrt(2 - r1);\n",
" double r2 = 2 * erand48(Xi),\n",
" dy = r2 < 1 ? sqrt(r2) - 1 : 1 - sqrt(2 - r2);\n",
" Vec d = cx * (((sx + .5 + dx) / 2 + x) / w - .5) +\n",
" cy * (((sy + .5 + dy) / 2 + y) / h - .5) + cam.d;\n",
" r = r + radiance(Ray(cam.o + d * 140, d.norm()), 0, Xi) * (1. / samps);\n",
" }\n",
" c[i] = c[i] + Vec(clamp(r.x), clamp(r.y), clamp(r.z)) * .25;\n",
" }\n",
" }\n",
" }\n",
" }\n",
"\n",
" // Map the pixel buffer to the SDL surface\n",
" uint8_t* pixels = (uint8_t*)surface->pixels;\n",
" for (int i = 0; i < w * h; i++) {\n",
" uint32_t* pixel_ptr = (uint32_t*)pixels + i;\n",
" *pixel_ptr = SDL_MapRGBA(surface->format, \n",
" toInt(c[i].x), // Red\n",
" toInt(c[i].y), // Green\n",
" toInt(c[i].z), // Blue\n",
" 255); // Alpha\n",
" }\n",
" std::cout << \"[DEBUG] Mapped pixel buffer to surface\" << std::endl;\n",
"\n",
" // Save the BMP to the filesystem\n",
" const std::string bmp_filename = \"render.bmp\";\n",
" save_bmp_to_filesystem(surface, bmp_filename);\n",
"\n",
" // Render the surface to Jupyter\n",
" render_sdl_surface_to_jupyter(surface, bmp_filename);\n",
"\n",
" // Cleanup\n",
" delete[] c;\n",
" SDL_Quit();\n",
" std::cout << \"[DEBUG] Exiting main\" << std::endl;\n",
"\n",
" return 0;\n",
"}\n",
"\n",
"main();"
]
}
],
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