Some draft ideas on simulation

1 files changed, 124 insertions, 0 deletions

diff --git a/src/main.cpp b/src/main.cpp
index e69de29..38f6961 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -0,0 +1,124 @@
+#include "common.hpp"
+#include "ui.hpp"
+
+#include <imgui.h>
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl3.h>
+#include <imgui_impl_opengl3_loader.h>
+#include <cstdio>
+#include <stdexcept>
+
+// Different packaging defines this inconsistently, e.g. Xrepo but not most Linux distros
+// We need it, so define just in case
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+#include <GLFW/glfw3native.h>
+
+static void glfw_error_handler(int err, const char* desc) {
+    fprintf(stderr, MSG_ERROR "GLFW error %d: %s", err, desc);
+}
+
+static const char* imgui_glsl_version = nullptr;
+
+struct GlfwInit {
+    GlfwInit() {
+        if (!glfwInit()) {
+            throw std::runtime_error("failed to init GLFW");
+        }
+        glfwSetErrorCallback(&glfw_error_handler);
+
+// Decide GL+GLSL versions
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+        // GL ES 2.0 + GLSL 100
+        imgui_glsl_version = "#version 100";
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+        glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
+#elif defined(__APPLE__)
+        // GL 3.2 + GLSL 150
+        imgui_glsl_version = "#version 150";
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // 3.2+ only
+        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // Required on Mac
+#else
+        // GL 3.0 + GLSL 130
+        imgui_glsl_version = "#version 130";
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+#endif
+    }
+
+    ~GlfwInit() {
+        glfwTerminate();
+    }
+};
+
+struct GlfwWindow {
+    GLFWwindow* _h;
+
+    GlfwWindow(int width, int height, const char* title) {
+        _h = glfwCreateWindow(width, height, title, nullptr, nullptr);
+        if (_h == nullptr)
+            throw std::runtime_error("failed to create GLFW window");
+    }
+
+    ~GlfwWindow() {
+        glfwDestroyWindow(_h);
+    }
+};
+
+struct ImGuiInit {
+    ImGuiInit(GLFWwindow* window) {
+        IMGUI_CHECKVERSION();
+        ImGui::CreateContext();
+
+        ImGui_ImplGlfw_InitForOpenGL(window, true);
+        ImGui_ImplOpenGL3_Init("#version 130");
+    }
+
+    ~ImGuiInit() {
+        ImGui_ImplOpenGL3_Shutdown();
+        ImGui_ImplGlfw_Shutdown();
+
+        ImGui::DestroyContext();
+    }
+};
+
+int main() {
+    GlfwInit i_glfw;
+
+    GlfwWindow i_window(1280, 730, "Sand Physics");
+    GLFWwindow* window = i_window._h;
+
+    glfwMakeContextCurrent(window);
+    // V-sync to make timing easier, we don't really care about latency
+    glfwSwapInterval(1);
+
+    ImGuiInit i_imgui(window);
+
+    ImVec4 bg_col(1.0f, 1.0f, 1.0f, 1.0f);
+    bg_col.x *= bg_col.w;
+    bg_col.y *= bg_col.w;
+    bg_col.z *= bg_col.w;
+
+    while (!glfwWindowShouldClose(window)) {
+        glfwPollEvents();
+
+        ImGui_ImplOpenGL3_NewFrame();
+        ImGui_ImplGlfw_NewFrame();
+        ImGui::NewFrame();
+
+        ShowEverything();
+
+        ImGui::Render();
+        int display_w, display_h;
+        glfwGetFramebufferSize(window, &display_w, &display_h);
+        glViewport(0, 0, display_w, display_h);
+        glClearColor(bg_col.x * bg_col.w, bg_col.y * bg_col.w, bg_col.z * bg_col.w, bg_col.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        glfwSwapBuffers(window);
+    }
+}
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