~ | Shader hot reloading

includes/RT.hpp

@@ -31,6 +31,7 @@
 # include "imgui/imgui_impl_glfw.h"
 # include "imgui/imgui_impl_opengl3.h"
 
+# include <filesystem>
 # include <algorithm>
 # include <string.h>
 # include <iostream>

includes/RT/Shader.hpp

@@ -25,9 +25,12 @@ class Shader
 		void	compile(void);
 		void	reload();
 
+		bool    hasChanged();
+		
 		void	setDefine(const std::string &name, const std::string &value);
 		
 		GLuint				getShader(void) const;
+		const std::string	&getFilePath(void) const;
 
 	private:
 		void	checkCompileErrors();
@@ -37,6 +40,8 @@ class Shader
 		GLenum						_type;
 		GLuint						_shader_id;
 		std::string					_file_path;
+
+		std::unordered_map<std::string, std::filesystem::file_time_type> _files_timestamps;
 };
 
 #endif

includes/RT/ShaderProgram.hpp

@@ -26,11 +26,12 @@ class ShaderProgram
 		
 		void	link(void);
 		
-		void	use(void) const;
-		void	dispathCompute(GLuint x, GLuint y, GLuint z) const;
+		void	use(void);
+		void	dispathCompute(GLuint x, GLuint y, GLuint z);
 		
 		void	bindImageTexture(GLuint texture_id, GLuint unit, GLenum access, GLenum format) const;
 
+		void	watchForChanges(void);
 		void	reloadShaders(void);
 
 		void	set_int(const std::string &name, int value) const;

shaders/compute.glsl

@@ -1,4 +1,4 @@
-#if SHADER_DEBUG
+#if 0
 #include "shaders/debug.glsl"
 #else
 #include "shaders/raytracing.glsl"

srcs/RT.cpp

@@ -14,35 +14,13 @@
 
 void					setupScreenTriangle(GLuint *VAO);
 void					drawScreenTriangle(GLuint VAO, GLuint output_texture, GLuint program);
+
 std::vector<GLuint>		generateTextures(unsigned int textures_count);
+
 std::vector<Buffer *>	createDataOnGPU(Scene &scene);
 void					updateDataOnGPU(Scene &scene, std::vector<Buffer *> buffers);
 
-void	shaderDenoise(ShaderProgram &denoising_program, GPUDenoise &denoise, std::vector<GLuint> textures)
-{
-	denoising_program.use();
-
-	denoising_program.set_vec2("u_resolution", glm::vec2(WIDTH, HEIGHT));
-	denoising_program.set_float("u_c_phi", denoise.c_phi);
-	denoising_program.set_float("u_p_phi", denoise.p_phi);
-	denoising_program.set_float("u_n_phi", denoise.n_phi);
-
-	int output_texture = 0;
-	int denoising_texture = 2;
-
-	for (int pass = 0; pass < denoise.pass ; ++pass)
-	{
-		glBindImageTexture(0, textures[output_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
-		glBindImageTexture(2, textures[denoising_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
-		
-		denoising_program.set_int("u_pass", pass);
-		denoising_program.dispathCompute((WIDTH + 15) / 16, (HEIGHT + 15) / 16, 1);
-
-		std::swap(output_texture, denoising_texture);
-	}
-
-	glBindImageTexture(0, textures[output_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
-}
+void					shaderDenoise(ShaderProgram &denoising_program, GPUDenoise &denoise, std::vector<GLuint> textures);
 
 int main(int argc, char **argv)
 {

srcs/RT_utils.cpp

@@ -115,3 +115,30 @@ void	updateDataOnGPU(Scene &scene, std::vector<Buffer *> buffers)
 	buffers[7]->update(&scene.getVolume(), sizeof(GPUVolume));
 	buffers[8]->update(&scene.getDebug(), sizeof(GPUDebug));
 }
+
+
+void	shaderDenoise(ShaderProgram &denoising_program, GPUDenoise &denoise, std::vector<GLuint> textures)
+{
+	denoising_program.use();
+
+	denoising_program.set_vec2("u_resolution", glm::vec2(WIDTH, HEIGHT));
+	denoising_program.set_float("u_c_phi", denoise.c_phi);
+	denoising_program.set_float("u_p_phi", denoise.p_phi);
+	denoising_program.set_float("u_n_phi", denoise.n_phi);
+
+	int output_texture = 0;
+	int denoising_texture = 2;
+
+	for (int pass = 0; pass < denoise.pass ; ++pass)
+	{
+		glBindImageTexture(0, textures[output_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
+		glBindImageTexture(2, textures[denoising_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
+		
+		denoising_program.set_int("u_pass", pass);
+		denoising_program.dispathCompute((WIDTH + 15) / 16, (HEIGHT + 15) / 16, 1);
+
+		std::swap(output_texture, denoising_texture);
+	}
+
+	glBindImageTexture(0, textures[output_texture], 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
+}

srcs/class/Shader.cpp

@@ -16,7 +16,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-std::stringstream loadFileWithIncludes(const std::string& path)
+std::stringstream loadFileWithIncludes(const std::string& path, std::vector<std::string> &included_files)
 {
     std::ifstream file(path);
     if (!file.is_open()) {
@@ -36,7 +36,9 @@ std::stringstream loadFileWithIncludes(const std::string& path)
             if (start != std::string::npos && end != std::string::npos && end > start)
 			{
                 std::string includePath = line.substr(start + 1, end - start - 1);
-                std::string includedContent = loadFileWithIncludes(includePath).str();
+                included_files.push_back(includePath);
+
+                std::string includedContent = loadFileWithIncludes(includePath, included_files).str();
                 fileContent << includedContent << "\n";
             }
         }
@@ -44,7 +46,7 @@ std::stringstream loadFileWithIncludes(const std::string& path)
             fileContent << line << "\n";
     }
 
-    return fileContent;
+    return (fileContent);
 }
 
 
@@ -78,7 +80,12 @@ void	Shader::compile()
 {
 	_shader_id = glCreateShader(_type);
 	
-	std::string shader_code = loadFileWithIncludes(_file_path).str();
+    std::vector<std::string> files;
+    files.push_back(_file_path);
+
+	std::string shader_code = loadFileWithIncludes(_file_path, files).str();
+    for (auto &file : files)
+        _files_timestamps[file] = std::filesystem::last_write_time(file);
 
     for (auto &define : _defines)
         shader_code = "#define SHADER_" + define.first + " " + define.second + "\n" + shader_code;
@@ -93,6 +100,19 @@ void	Shader::compile()
 	this->checkCompileErrors();
 }
 
+bool    Shader::hasChanged()
+{
+    for (auto &file : _files_timestamps)
+    {
+        if (std::filesystem::last_write_time(file.first) != file.second)
+        {
+            _files_timestamps[file.first] = std::filesystem::last_write_time(file.first);
+            return (true);
+        }
+    }
+    return (false);
+}
+
 void Shader::reload()
 {
 	glDeleteShader(_shader_id);
@@ -122,3 +142,7 @@ GLuint	Shader::getShader(void) const
 	return (_shader_id);
 }
 
+const std::string	&Shader::getFilePath(void) const
+{
+    return (_file_path);
+}

srcs/class/ShaderProgram.cpp

@@ -50,12 +50,13 @@ void	ShaderProgram::link()
 	}
 }
 
-void	ShaderProgram::use() const
+void	ShaderProgram::use()
 {
 	glUseProgram(_program);
+	this->watchForChanges();
 }
 
-void	ShaderProgram::dispathCompute(GLuint x, GLuint y, GLuint z) const
+void	ShaderProgram::dispathCompute(GLuint x, GLuint y, GLuint z)
 {
 	this->use();
 	glDispatchCompute(x, y, z);
@@ -67,6 +68,19 @@ void	ShaderProgram::bindImageTexture(GLuint texture_id, GLuint unit, GLenum acce
 	glBindImageTexture(unit, texture_id, 0, GL_FALSE, 0, access, format);
 }
 
+void	ShaderProgram::watchForChanges(void)
+{
+	for (Shader *shader : _shaders)
+	{
+		if (shader->hasChanged())
+		{
+			std::cout << "Shader " << shader->getFilePath() << " has changed" << std::endl;
+			this->reloadShaders();
+			break;
+		}
+	}
+}
+
 void	ShaderProgram::reloadShaders(void)
 {
 	std::cout << "Reloading shaders" << std::endl;