[#69] add ParticleSystem basics

projects/particle_simulation/CMakeLists.txt

@@ -9,7 +9,8 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 
 # adding source files to the project
-add_executable(particle_simulation src/main.cpp)
+add_executable(particle_simulation src/main.cpp
+		src/ParticleSystem.hpp src/ParticleSystem.cpp)
 
 # this should fix the execution path to load local files from the project (for MSVC)
 if(MSVC)

projects/particle_simulation/shaders/shader.vert

 #version 450 core
 #extension GL_ARB_separate_shader_objects : enable
 
-layout(location = 0) in vec3 position;
+layout(location = 0) in vec3 particle;
 
 layout( push_constant ) uniform constants{
     mat4 mvp;
@@ -9,5 +9,5 @@ layout( push_constant ) uniform constants{
 
 void main()
 {
-	gl_Position = mvp * vec4(position, 1.0);
+	gl_Position = mvp * vec4(particle, 1.0);
 }
\ No newline at end of file

projects/particle_simulation/src/ParticleSystem.cpp

+#include "ParticleSystem.hpp"
+
+const std::vector<Particle>& ParticleSystem::getParticles() const {
+    return m_particles;
+}
+
+void ParticleSystem::addParticle( const Particle particle ){
+    m_particles.push_back(particle);
+}
+void ParticleSystem::addParticles( const std::vector<Particle> particles ){
+    m_particles.insert(m_particles.end(), particles.begin(), particles.end());
+}
\ No newline at end of file

projects/particle_simulation/src/ParticleSystem.hpp

+#pragma once
+
+#include <glm/glm.hpp>
+#include <vector>
+
+struct Particle{
+    Particle(glm::vec3 position, glm::vec3 velocity)
+    noexcept
+    : m_position(position),
+    m_velocity(velocity)
+    {}
+
+    // all properties of the Particle
+    glm::vec3 m_position;
+    float padding = 0.f;
+    glm::vec3 m_velocity;
+    float padding_2 = 0.f;
+};
+
+class ParticleSystem {
+
+public:
+    const std::vector<Particle> &getParticles() const;
+    void addParticle( const Particle particle );
+    void addParticles( const std::vector<Particle> particles );
+
+private:
+    std::vector<Particle> m_particles;
+
+};

projects/particle_simulation/src/main.cpp

@@ -3,6 +3,7 @@
 #include <GLFW/glfw3.h>
 #include <vkcv/camera/CameraManager.hpp>
 #include <chrono>
+#include "ParticleSystem.hpp"
 
 int main(int argc, const char** argv) {
     const char* applicationName = "Particlesystem";
@@ -62,25 +63,27 @@ int main(int argc, const char** argv) {
 
     vkcv::DescriptorSetHandle descriptorSet = core.createDescriptorSet(descriptorBindings);
 
-    vkcv::Buffer<glm::vec3> vertexbuffer = core.createBuffer<glm::vec3>(
+    vkcv::Buffer<Particle> vertexBuffer = core.createBuffer<Particle>(
             vkcv::BufferType::VERTEX,
             3
     );
 
-    const std::vector<glm::vec3> vertices = {glm::vec3(-0.5, 0.5, -1),
-                                             glm::vec3( 0.5, 0.5, -1),
-                                             glm::vec3(0, -0.5, -1)};
-
-    vertexbuffer.fill(vertices);
+    ParticleSystem particleSystem;
+    particleSystem.addParticles({
+                                        Particle(glm::vec3(-0.5, 0.5, -1), glm::vec3(0.f)),
+                                        Particle(glm::vec3(0.5, 0.5, -1), glm::vec3(0.f)),
+                                        Particle(glm::vec3(0, -0.5, -1), glm::vec3(0.f))});
 
+    vertexBuffer.fill(particleSystem.getParticles());
 
     vkcv::VertexAttribute attrib = vkcv::VertexAttribute{
             vkcv::PrimitiveType::POSITION,
-            0,
-            sizeof(glm::vec3) * vertices.size(),
-            0,
+            offsetof(Particle, m_position),
+            sizeof(Particle::m_position) * particleSystem.getParticles().size(),
+            sizeof(Particle) - sizeof(Particle::m_position), // why is this the difference and not the total size? maybe calced after the last element not from the first like OpenGL
             5126,
-            3};
+            sizeof(Particle::m_position) / sizeof(float)// number of elements, like vec3 = 3
+            };
 
     const vkcv::PipelineConfig particlePipelineDefinition(
             particleShaderProgram,
@@ -103,7 +106,7 @@ int main(int argc, const char** argv) {
     );
 
     const std::vector<vkcv::VertexBufferBinding> vertexBufferBindings = {
-            vkcv::VertexBufferBinding(0, vertexbuffer.getVulkanHandle())
+            vkcv::VertexBufferBinding(0, vertexBuffer.getVulkanHandle())
     };
 
     vkcv::DescriptorWrites setWrites;