feat: real-time CUDA rendering

.clang-format

@@ -0,0 +1,45 @@
+BasedOnStyle: LLVM
+IndentWidth: 4
+ContinuationIndentWidth: 4
+PointerAlignment: Left
+ColumnLimit: 80
+
+# Function declaration and definition
+AlignAfterOpenBracket: BlockIndent
+AllowAllArgumentsOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AlwaysBreakAfterReturnType: None
+PenaltyReturnTypeOnItsOwnLine: 1000 # add big penalty so that return type never has its own line
+
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+BinPackArguments: false
+BinPackParameters: false
+
+BreakBeforeBinaryOperators: All
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+MaxEmptyLinesToKeep: 1
+
+AlwaysBreakTemplateDeclarations: Yes
+
+BreakBeforeBraces: Custom
+BraceWrapping:
+  AfterClass: true
+  AfterEnum: true
+  AfterStruct: true
+  AfterFunction: false
+  AfterNamespace: true
+  SplitEmptyFunction: true
+
+SeparateDefinitionBlocks: Always
+
+SortIncludes: CaseSensitive
+# multipel declarations are aligned to right
+# AlignConsecutiveDeclarations:
+#   Enabled: true
+#   AcrossEmptyLines: true
+#   AcrossComments: false
+#   AlignCompound: true
+#   PadOperators: true

.gitignore

@@ -1,10 +1,15 @@
 # dependencies
 /Dependencies
 
+# temp files
+/.cache
+
 # building
+/debug
 /Debug
 /Release
 /x64
+/build
 
 # Visual Studio Project Files
 .vs/
@@ -15,4 +20,4 @@
 
 # renders
 *.png
-renders/
+renders/

.vscode/launch.json

@@ -0,0 +1,33 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+            {
+                    "name": "(gdb) Launch",
+                    "type": "cppdbg",
+                    "request": "launch",
+                    "program": "${workspaceFolder}/debug/rodent_raytracer",
+                    "args": [],
+                    "stopAtEntry": false,
+                    "cwd": "${workspaceFolder}/debug/",
+                    "environment": [],
+                    "externalConsole": false,
+                    "MIMode": "gdb",
+                    "setupCommands": [
+                        {
+                            "description": "Enable pretty-printing for gdb",
+                            "text": "-enable-pretty-printing",
+                            "ignoreFailures": true
+                        },
+                        {
+                            "description": "Set Disassembly Flavor to Intel",
+                            "text": "-gdb-set disassembly-flavor intel",
+                            "ignoreFailures": true
+                        }
+                    ]
+            }
+
+    ]
+}

CMakeLists.txt

@@ -0,0 +1,49 @@
+cmake_minimum_required(VERSION 3.22)
+# set(CMAKE_C_COMPILER "/usr/bin/gcc")
+# set(CMAKE_CXX_COMPILER "/usr/bin/g++")
+# set(CMAKE_CUDA_COMPILER "/usr/local/cuda-12/bin/nvcc")
+
+enable_language(CUDA)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+project(rodent_raytracer LANGUAGES CXX CUDA)
+set(CMAKE_CXX_STANDARD 17)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
+option(BUILD_SHARED_LIBS "Build shared libraries" OFF)
+
+# SFML fuckery
+include(FetchContent)
+FetchContent_Declare(SFML
+    GIT_REPOSITORY https://github.com/SFML/SFML.git
+    GIT_TAG 2.6.x)
+FetchContent_MakeAvailable(SFML)
+
+add_executable(
+    rodent_raytracer
+    src/main.cpp
+    src/Primitive.cpp
+    src/Renderer.cpp
+    src/util/Math.cpp
+    src/util/Window.cpp
+    src/gpu.cu
+    src/Camera.cpp
+    src/Image.cpp
+    src/Rotor.cpp
+)
+
+
+set(SFML_LIBRARIES sfml-graphics sfml-window sfml-system)
+
+target_include_directories(rodent_raytracer PUBLIC ${SFML_INCLUDE_DIRS})
+target_link_libraries(rodent_raytracer PRIVATE ${SFML_LIBRARIES} ${SFML_DEPENDENCIES})
+target_precompile_headers(rodent_raytracer PRIVATE src/PCH.h)
+
+
+# CUDA stuff
+# set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} -arch=sm_60")
+
+# set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} -arch=sm_60")
+set_target_properties(rodent_raytracer PROPERTIES CUDA_ARCHITECTURES "86")
+

readme.md

@@ -0,0 +1,42 @@
+# Geosim-RTX
+
+CUDA-based real-time ray marcher for physically-based rendering of geometries in H3 space.
+
+## Results
+
+|![solar system naive](results/solar_system_naive.gif)|
+|:--:| 
+| _Looks just like a naive solar system from afar_|
+
+|![solar system](results/solar_system.gif)|
+|:--:| 
+| _Light doesn't travel in straight path_|
+
+|![solar system 2](results/solar_system_2.gif)|
+|:--:| 
+| _Spheres rotating appear to be "moving away"_ |
+
+## Build
+
+### Requirements
+
+- `CUDA 11.8` or above && `nvcc`
+- `CMake`
+- `make`
+- `gcc`
+- `glm`
+
+```bash
+mkdir build
+cd build
+cmake ..
+make
+```
+
+
+## Reference
+
+[Ray-marching Thurston geometries](https://arxiv.org/abs/2010.15801)
+
+[Non-euclidean virtual reality I: explorations of ℍ3](https://arxiv.org/abs/1702.04004)
+

src/Camera.cpp

@@ -0,0 +1,18 @@
+#include "Camera.h"
+
+void Camera::updateViewMat() {
+    // derive forward direction of camera from its euler angles
+    forwardDir.x = cosf(yaw) * cosf(pitch);
+    forwardDir.y = sinf(pitch);
+    forwardDir.z = sinf(yaw) * cosf(pitch);
+
+    static constexpr glm::vec3 GLOBAL_UP{0.f, 1.f, 0.f};
+
+    // unitize and calculate relative up and right direction of the camera
+    forwardDir = glm::normalize(forwardDir);
+    rightDir = glm::normalize(glm::cross(forwardDir, GLOBAL_UP));
+    upDir = glm::normalize(glm::cross(rightDir, forwardDir));
+
+    const glm::vec3 targetPosition{position + forwardDir};
+    viewMat = glm::lookAt(position, targetPosition, upDir);
+}

src/Camera.h

@@ -26,21 +26,5 @@ struct Camera
 
 	glm::mat4 viewMat{ 1.f };
 
-	void updateViewMat()
-	{
-		// derive forward direction of camera from its euler angles
-		forwardDir.x = cosf(yaw) * cosf(pitch);
-		forwardDir.y = sinf(pitch);
-		forwardDir.z = sinf(yaw) * cosf(pitch);
-
-		static constexpr glm::vec3 GLOBAL_UP{ 0.f, 1.f, 0.f };
-
-		// unitize and calculate relative up and right direction of the camera
-		forwardDir = glm::normalize(forwardDir);
-		rightDir = glm::normalize(glm::cross(forwardDir, GLOBAL_UP));
-		upDir = glm::normalize(glm::cross(rightDir, forwardDir));
-
-		const glm::vec3 targetPosition{ position + forwardDir };
-		viewMat = glm::lookAt(position, targetPosition, upDir);
-	}
-};
+    void updateViewMat();
+};

src/Image.cpp

@@ -0,0 +1,32 @@
+#include <SFML/Graphics/Image.hpp>
+
+#include "Image.h"
+
+
+void Image::setPixel(const glm::vec2& ndc, const glm::vec3& pixelData) {
+    glm::uvec2 pixelCoord{ndc.x * width, ndc.y * height};
+
+    int index = pixelCoord.x + (pixelCoord.y * width);
+
+    pixels[index] = pixelData;
+}
+void Image::saveToFile(const std::string& filename) {
+    std::vector<sf::Uint8> uint8Pixels;
+
+    for (const glm::vec3& pixel : pixels) {
+        uint8Pixels.push_back(pixel.r * 255);
+        uint8Pixels.push_back(pixel.g * 255);
+        uint8Pixels.push_back(pixel.b * 255);
+
+        static constexpr bool ALWAYS_OPAQUE{true};
+
+        if constexpr (ALWAYS_OPAQUE)
+            uint8Pixels.push_back(255);
+        // else
+        //	uint8Pixels.push_back(pixel.a * 255);
+    }
+
+    sf::Image i;
+    i.create(width, height, uint8Pixels.data());
+    i.saveToFile(filename + " hash" + std::to_string((uint64_t)&i) + ".png");
+}

src/Image.h

@@ -1,57 +1,20 @@
 #pragma once
 
+#include <string>
 #include <glm/glm.hpp>
 
 #include <vector>
 
-#include <SFML/Graphics/Image.hpp>
-
-struct Image
-{
-	const unsigned width;
-	const unsigned height;
-
-	std::vector<glm::vec3> pixels;
-
-	Image(unsigned width, unsigned height)
-		:
-		width{ width },
-		height{ height },
-		pixels{ width * height }
-	{}
-
-	void setPixel(const glm::vec2& ndc, const glm::vec3& pixelData)
-	{
-		glm::uvec2 pixelCoord{
-			ndc.x * width,
-			ndc.y * height
-		};
-
-		int index = pixelCoord.x + (pixelCoord.y * width);
-
-		pixels[index] = pixelData;
-	}
-
-	void saveToFile(const std::string& filename)
-	{
-		std::vector<sf::Uint8> uint8Pixels;
-
-		for (const glm::vec3& pixel : pixels)
-		{
-			uint8Pixels.push_back(pixel.r * 255);
-			uint8Pixels.push_back(pixel.g * 255);
-			uint8Pixels.push_back(pixel.b * 255);
-
-			static constexpr bool ALWAYS_OPAQUE{ true };
-
-			if constexpr (ALWAYS_OPAQUE)
-				uint8Pixels.push_back(255);
-			//else
-			//	uint8Pixels.push_back(pixel.a * 255);
-		}
-
-		sf::Image i;
-		i.create(width, height, uint8Pixels.data());
-		i.saveToFile(filename + " hash" + std::to_string((unsigned)&i) + ".png");
-	}
-};
+
+struct Image {
+    const unsigned width;
+    const unsigned height;
+
+    std::vector<glm::vec3> pixels;
+
+    Image(unsigned width, unsigned height) : width{width}, height{height}, pixels{width * height} {}
+
+    void setPixel(const glm::vec2& ndc, const glm::vec3& pixelData);
+
+    void saveToFile(const std::string& filename);
+};

src/PCH.h

@@ -0,0 +1,2 @@
+#define CUDA_ONCE 0
+#define CUDA 1