raymarch_ascii

raymarch.cpp

#include <Windows.h>
#define GLM_SWIZZLE
#include <glm/glm.hpp>
#include <ctime>

const auto WIDTH = 100;
const auto HEIGHT = 50;
const auto PALETTE = " `-_:/~|(%zr*uwJ$khOZ8W@B#M";
const auto STEP = 0.037037f;

glm::vec3 opRep(glm::vec3 p, glm::vec3 c) {
	return mod(p, c) - 0.5f * c;
}

float sdBox(glm::vec3 p, glm::vec3 b) {
	auto d = abs(p) - b;
	return glm::min(glm::max(d.x, glm::max(d.y, d.z)), 0.f) + length(max(d, 0.f));
}

float trace(glm::vec3 o, glm::vec3 r) {
	auto t = 0.f;
	for (auto i = 0; i < 50; i++) {
		auto p = o + r * t;
		t += sdBox(opRep(p, glm::vec3(66.f)), glm::vec3(8.f));
	}
	return t;
}

glm::mat2 rotate(float angle) {
	return glm::mat2(cos(angle), -sin(angle), sin(angle), cos(angle));
}

int main() {
	auto wHnd = GetStdHandle(STD_OUTPUT_HANDLE);
	SMALL_RECT windowSize = {0, 0, WIDTH, HEIGHT};
	SetConsoleWindowInfo(wHnd, TRUE, &windowSize);
	SetConsoleScreenBufferSize(wHnd, {WIDTH, HEIGHT});
	CHAR_INFO consoleBuffer[WIDTH * HEIGHT];
	SMALL_RECT writeArea = {0, 0, WIDTH - 1, HEIGHT - 1};

	while (1) {
		for (auto y = 0; y < HEIGHT; ++y) {
			for (auto x = 0; x <= WIDTH; ++x) {
				auto uv = glm::vec2(x, y) / glm::vec2(WIDTH, HEIGHT) * 2.f - 1.f;
				uv.x *= WIDTH / HEIGHT;

				auto r = normalize(glm::vec3(uv, 1.f));
				r.xz = rotate(clock() * 0.001f) * r.xz;
				r.yz = rotate(clock() * 0.001f) * r.yz;

				auto o = glm::vec3(0.f, 3.f, clock() * 0.1f);
				auto t = trace(o, r);
				auto fc = 1.f / (1.f + t * t * 0.00004f);

				auto i = static_cast<int>(fc / STEP);
				consoleBuffer[x + WIDTH * y].Char.AsciiChar = PALETTE[i];
				consoleBuffer[x + WIDTH * y].Attributes = FOREGROUND_RED | FOREGROUND_BLUE | FOREGROUND_GREEN;
			}
		}
		WriteConsoleOutputA(wHnd, consoleBuffer, {WIDTH, HEIGHT}, {0, 0}, &writeArea);
	}
}

Nice!