working project

Shaders/Compute.glsl

@@ -2,31 +2,40 @@
 
 layout(rgba32f, binding = 0) uniform writeonly image2D outputImage;
 
-layout(local_size_x = 16, local_size_y = 16) in;
+layout(std430, binding = 3) buffer layoutName
+{
+  vec2 o_Points[];
+};
+
+// 1 -> 1
+// 2 -> 3
+// 3 -> 9
+// 4 -> 27
+// 5 -> 81
+// 6 -> 243
+// ...
+
+// 4  27
+// 1 + 3 + 9 = 13
+
+// Sn = ((3^n)-1)/2
+// S3 = 3^3 - 1 / 2
+// 3^4
+
+// gl_NumWorkGroups : This variable contains the number of work groups passed to the dispatch function.
+// gl_WorkGroupID : This is the current work group for this shader invocation. Each of the XYZ components will be on the half-open range [0, gl_NumWorkGroups.XYZ).
+// gl_LocalInvocationID : This is the current invocation of the shader within the work group. Each of the XYZ components will be on the half-open range [0, gl_WorkGroupSize.XYZ).
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main()
 {
-    ivec2 pixelCoord = ivec2(gl_GlobalInvocationID.xy);
+    uint triangleCount = gl_NumWorkGroups.x;
+    uint currentPoint = gl_WorkGroupID.x;
 
-    if (pixelCoord.x >= imageSize(outputImage).x || pixelCoord.y >= imageSize(outputImage).y)
-		return;
+    uint offset = (triangleCount - 1) / 2;
 
-    ivec2 texSize = imageSize(outputImage);
-    vec2 fTexSize = vec2(texSize);
-    vec2 normalizedCoord = vec2(pixelCoord) / vec2(texSize);
-
-    vec4 O = vec4(0, 0, 0, 1);
-    vec2 I = vec2(pixelCoord);
-
-    float iTime = 2.2;
-    float i = 0.0, t=iTime;
-    O *= i;
-    for(vec2 a=fTexSize.xy, p=(I+I-a)/a.y; i++<20.;
-        O += (cos(sin(i*.2+t)*vec4(0,4,3,1))+2.)
-        /(i/1e3+abs(length(a-.5*min(a+a.yx,.1))-.05)))
-        a.x = abs(a = (fract(.2*t+.3*p*i*mat2(cos(cos(.2*t+.2*i)+vec4(0,11,33,0))))-.5)).x;
-        
-    O = tanh(O*O/2e5);
-
-    vec4 color = vec4(normalizedCoord, 0.0, 1.0);
-    imageStore(outputImage, pixelCoord, O);
+    uint firstPointIndex = offset * 3 + 1;
+    o_Points[firstPointIndex + currentPoint * 3 ] = o_Points[offset + currentPoint] / 2 + vec2(0, 0.36);
+    o_Points[firstPointIndex + currentPoint * 3 + 1] = o_Points[offset + currentPoint] / 2 + vec2(-0.5, -0.5);
+    o_Points[firstPointIndex + currentPoint * 3 + 2] = o_Points[offset + currentPoint] / 2 + vec2(0.5, -0.5);
 }

Shaders/Fragment.glsl

@@ -0,0 +1,8 @@
+#version 460 core
+
+layout (location = 0) out vec4 o_Color;
+
+void main()
+{
+    o_Color = vec4(1, 1, 1, 1); 
+}

Shaders/Vertex.glsl

@@ -0,0 +1,15 @@
+#version 460 core
+
+layout(location = 0) in vec2 a_Position;
+
+layout(std430, binding = 3) buffer layoutName
+{
+    vec2 data_SSBO[];
+};
+
+out vec2 v_TexCoord;
+
+void main()
+{
+	gl_Position = vec4(data_SSBO[gl_InstanceID], 0.0, 1.0);
+}

src/Main.cpp

@@ -1,12 +1,45 @@
 #include <iostream>
 
 #include <glm/glm.hpp>
+#include <glm/gtc/type_ptr.hpp>
 
 #include "Shader.h"
 #include "Renderer.h"
 
+#include <chrono>
+
+class Timer
+{
+public:
+	Timer() { Reset(); }
+	void Reset() { m_Start = std::chrono::high_resolution_clock::now(); }
+	float Elapsed() const { return std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now() - m_Start).count() * 0.001f * 0.001f; }
+	float ElapsedMillis() const { return std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now() - m_Start).count() * 0.001f; }
+
+private:
+	std::chrono::time_point<std::chrono::high_resolution_clock> m_Start;
+};
+
+class ScopedTimer
+{
+public:
+	ScopedTimer(std::string_view name) : m_Name(name) {}
+	~ScopedTimer()
+	{
+		float time = m_Timer.ElapsedMillis();
+		std::cout << m_Name << " - " << time << "ms\n";
+	}
+
+private:
+	Timer m_Timer;
+	std::string m_Name;
+};
+
 static uint32_t s_ComputeShader = -1;
+static uint32_t s_GraphicsShader = -1;
 static const std::filesystem::path s_ComputeShaderPath = "Shaders/Compute.glsl";
+static const std::filesystem::path s_VertexShaderPath = "Shaders/Vertex.glsl";
+static const std::filesystem::path s_FragmentShaderPath = "Shaders/Fragment.glsl";
 
 static void ErrorCallback(int error, const char *description)
 {
@@ -15,11 +48,46 @@ static void ErrorCallback(int error, const char* description)
 
 static void KeyCallback(GLFWwindow *window, int key, int scancode, int action, int mods)
 {
+	if (action != GLFW_PRESS)
+		return;
+
 	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
 		glfwSetWindowShouldClose(window, GLFW_TRUE);
 
 	if (key == GLFW_KEY_R)
+	{
 		s_ComputeShader = ReloadComputeShader(s_ComputeShader, s_ComputeShaderPath);
+		s_GraphicsShader = ReloadGraphicsShader(s_GraphicsShader, s_VertexShaderPath, s_FragmentShaderPath);
+	}
+}
+
+std::vector<float> GenPoints(float x, float y)
+{
+	x /= 2;
+	y /= 2;
+	return {
+		x, y + 0.36f,
+		x - 0.5f, y - 0.5f,
+		x + 0.5f, y - 0.5f};
+}
+
+std::vector<float> GetPoints(int depth)
+{
+	std::vector<float> result = {0.0f, 0.0f};
+	std::size_t offset = 0;
+	std::size_t count = 1;
+	for (std::size_t i = 1; i < depth; i++)
+	{
+		for (std::size_t j = 0; j < count; j++)
+		{
+			std::size_t index = offset + j * 2;
+			auto newPoints = GenPoints(result[index], result[index + 1]);
+			result.insert(result.end(), newPoints.begin(), newPoints.end());
+		}
+		offset += count * 2;
+		count *= 3;
+	}
+	return result;
 }
 
 int main()
@@ -55,11 +123,82 @@ int main()
 		return -1;
 	}
 
+	s_GraphicsShader = CreateGraphicsShader(s_VertexShaderPath, s_FragmentShaderPath);
+	if (s_GraphicsShader == -1)
+	{
+		std::cerr << "Graphics shader failed\n";
+		return -1;
+	}
+
 	Texture computeShaderTexture = CreateTexture(width, height);
 	Framebuffer fb = CreateFramebufferWithTexture(computeShaderTexture);
 
+	GLuint vertexArray;
+	glCreateVertexArrays(1, &vertexArray);
+
+	GLuint vertexBuffer;
+	glCreateBuffers(1, &vertexBuffer);
+
+	constexpr int DEPTH = 13;
+
+	auto vertices = GetPoints(DEPTH);
+
+	glNamedBufferData(vertexBuffer, sizeof(float) * vertices.size(), vertices.data(), GL_STATIC_DRAW);
+
+	glVertexArrayVertexBuffer(vertexArray, 0, vertexBuffer, 0, sizeof(float) * 2);
+
+	glEnableVertexArrayAttrib(vertexArray, 0);
+	glEnableVertexArrayAttrib(vertexArray, 1);
+
+	glVertexArrayAttribFormat(vertexArray, 0, 2, GL_FLOAT, GL_FALSE, 0);
+
+	glVertexArrayAttribBinding(vertexArray, 0, 0);
+	glVertexArrayAttribBinding(vertexArray, 1, 0);
+
+	GLuint ssbo;
+	glGenBuffers(1, &ssbo);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo);
+	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, ssbo);
+	glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(float) * vertices.size(), nullptr, GL_DYNAMIC_COPY); // sizeof(data) only works for statically sized C/C++ arrays.
+
+	float lastTime = (float)glfwGetTime();
+
+	int fps = 0;
+	float secondsTimer = 0.0f;
+
+	// Compute
+	glUseProgram(s_ComputeShader);
+	glBindImageTexture(0, fb.ColorAttachment.Handle, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA32F);
+
+	std::size_t count = 1;
+	for (std::size_t i = 0; i < DEPTH; i++)
+	{
+		glDispatchCompute(count, 1, 1);
+
+		// Ensure all writes to the image are complete
+		glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
+
+		count *= 3;
+	}
+
 	while (!glfwWindowShouldClose(window))
 	{
+		// ScopedTimer timer("Main Loop");
+
+		float currentTime = (float)glfwGetTime();
+		float dt = currentTime - lastTime;
+		lastTime = currentTime;
+
+		secondsTimer += dt;
+		if (secondsTimer >= 1.0f)
+		{
+			std::string title = "FPS : " + std::to_string(fps);
+			glfwSetWindowTitle(window, title.c_str());
+
+			secondsTimer = 0.0f;
+			fps = 0;
+		}
+
 		glfwGetFramebufferSize(window, &width, &height);
 
 		// Resize texture
@@ -70,22 +209,14 @@ int main()
 			AttachTextureToFramebuffer(fb, computeShaderTexture);
 		}
 
-		// Compute
-		{
-			glUseProgram(s_ComputeShader);
-			glBindImageTexture(0, fb.ColorAttachment.Handle, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA32F);
+		// Graphics
+		glBindFramebuffer(GL_FRAMEBUFFER, fb.Handle);
+		glUseProgram(s_GraphicsShader);
 
-			const GLuint workGroupSizeX = 16;
-			const GLuint workGroupSizeY = 16;
+		glBindVertexArray(vertexArray);
+		glDrawArraysInstanced(GL_POINTS, 0, 1, vertices.size());
 
-			GLuint numGroupsX = (width + workGroupSizeX - 1) / workGroupSizeX;
-			GLuint numGroupsY = (height + workGroupSizeY - 1) / workGroupSizeY;
-
-			glDispatchCompute(numGroupsX, numGroupsY, 1);
-
-			// Ensure all writes to the image are complete
-			glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
-		}
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
 		// Blit
 		{
@@ -94,6 +225,11 @@ int main()
 
 		glfwSwapBuffers(window);
 		glfwPollEvents();
+
+		glClear(GL_COLOR_BUFFER_BIT);
+		glClearColor(0, 0, 0, 1);
+
+		fps++;
 	}
 
 	glfwDestroyWindow(window);