Add src/main.cpp; wire everything together

src/main.cpp

@@ -0,0 +1,147 @@
+#include <memory>
+#include <iostream>
+#include <cstdlib>
+
+#include <imgui.h>
+#include <imgui_impl_glfw_gl3.h>
+#include <GL/gl3w.h>
+#include <GLFW/glfw3.h>
+
+#include "gui.h"
+#include "state.h"
+
+#define CLEAR_COLOR 0.0, 0.0, 0.0, 1.0
+
+static void glfw_error_callback(int error, const char* description) {
+	std::cerr << "GLFW error " << error << " " << description << '\n';
+}
+
+// static void glfw_key_callback(GLFWwindow *window, int key, int scancode, int action, int mods) {
+// 	if (key == GLFW_KEY_R && mods == GLFW_MOD_CONTROL && action == GLFW_PRESS) {
+// 		printf("...\n");
+// 	}
+// }
+
+int main(int argc, char* argv[]) {
+	glfwSetErrorCallback(glfw_error_callback);
+
+	if (!glfwInit()){
+		// glfw init failed; crash out
+		std::clog << "GLFW: init failed; exiting.\n";
+		std::exit(-1);
+	}
+
+	// request at least OpenGL v3.3
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, 1);
+
+	auto window = glfwCreateWindow(1024, 768, "Zinnia", NULL, NULL);
+	if (!window) {
+		// window creation failed
+		glfwTerminate();
+		std::clog << "GLFW: failed to create window; exiting.\n";
+		return EXIT_FAILURE;
+	}
+
+	glfwMakeContextCurrent(window);
+	glfwSwapInterval(1);
+	if (gl3wInit()) {
+		std::clog << "Failed to initialize OpenGL\n";
+		return EXIT_FAILURE;
+	}
+
+	std::cout << "[GL] OpenGL v" << glGetString(GL_VERSION)
+		<< ", GLSL v" << glGetString(GL_SHADING_LANGUAGE_VERSION) << '\n';
+
+	ImGui_ImplGlfwGL3_Init(window, true);
+
+	// demo state
+	auto config = Config::from_file("../config.toml");
+	auto state = DemoState(std::make_shared<Config>(config));
+
+	// set up a GUI state
+	auto gui = Gui(&state);
+
+	if (argc == 2) {
+		auto proj = Project::fromFile(std::string(argv[1]));
+		state.current_project = std::move(proj);
+	}
+
+	const GLfloat v_quad[][2] = {
+		{1, 1}, {1, -1}, {-1, -1}, {-1, 1},
+	};
+	const GLuint i_quad[] = {
+		0, 1, 3,
+		1, 2, 3,
+	};
+	GLuint vao, vbo, ebo;
+	glGenVertexArrays(1, &vao);
+
+	glGenBuffers(1, &ebo);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(i_quad), i_quad, GL_STATIC_DRAW);
+
+	glBindVertexArray(vao);
+		glGenBuffers(1, &vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, vbo);
+		glBufferData(GL_ARRAY_BUFFER, sizeof(v_quad), v_quad, GL_STATIC_DRAW);
+
+		glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
+		glEnableVertexAttribArray(0);
+	glBindVertexArray(0);
+
+	double t, t_prev, dt;
+	glfwSetTime(0); t_prev = glfwGetTime();
+	while(!glfwWindowShouldClose(window) && state.running) {
+		t = glfwGetTime();
+		dt = t - t_prev; t_prev = t;
+		
+		glfwPollEvents();
+		ImGui_ImplGlfwGL3_NewFrame();
+
+		glfwGetFramebufferSize(window, &state.width, &state.height);
+		state.ratio = (float)state.width / (float)state.height;
+
+		glViewport(0, 0, (float)state.width, (float)state.height);
+		glClearColor(CLEAR_COLOR);
+		glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
+
+		if (state.current_project != nullptr) {
+			if (state.current_project->scene_loaded) {
+				auto prog = *state.current_project->current_scene->shader_p;
+				auto u_resolution = glGetUniformLocation(prog, "u_Resolution");
+				auto u_mouse = glGetUniformLocation(prog, "u_Mouse");
+				auto u_time = glGetUniformLocation(prog, "u_Time");
+
+				double m_x, m_y;
+				glfwGetCursorPos(window, &m_x, &m_y);
+
+				glUseProgram(prog);
+				glUniform2f(u_resolution, (float)state.width, (float)state.height);
+				glUniform4f(u_mouse, m_x, m_y, 0., 0.);
+				glUniform1f(u_time, t);
+				glBindVertexArray(vao);
+				glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
+					glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+				glBindVertexArray(0);
+			}
+		}
+
+		gui.render();
+		ImGui::Render();
+
+		glfwSwapBuffers(window);
+
+		std::cout << std::flush;
+		std::cerr << std::flush;
+	}
+
+	ImGui_ImplGlfwGL3_Shutdown();
+
+	glfwDestroyWindow(window);
+	glfwTerminate();
+	return 0;
+}