feat: Add ImGui-based developer console overlay

Integrates Dear ImGui for an in-game debug console that replaces the
blocking Python REPL. Press ~ (grave/tilde) to toggle the console.

Features:
- Python code execution without blocking the game loop
- Output capture with color coding (yellow=input, red=errors, gray=output)
- Expression results show repr() automatically
- Command history navigation with up/down arrows
- Word wrapping for long output lines
- Auto-scroll that doesn't fight manual scrolling
- mcrfpy.setDevConsole(bool) API to disable for shipping

Technical changes:
- Update imgui submodule to v1.89.9 (stable)
- Update imgui-sfml submodule to 2.6.x branch (SFML 2.x compatible)
- Add ImGui sources to CMakeLists.txt with OpenGL dependency
- Integrate ImGui lifecycle into GameEngine
- Add ImGuiConsole class for console overlay

closes #36, closes #65, closes #75

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
John McCardle 2025-11-26 20:03:58 -05:00
commit 3f6ea4fe33
9 changed files with 405 additions and 10 deletions

246
src/ImGuiConsole.cpp Normal file
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#include "ImGuiConsole.h"
#include "imgui.h"
#include "McRFPy_API.h"
#include <Python.h>
#include <sstream>
// Static member initialization
bool ImGuiConsole::enabled = true;
ImGuiConsole::ImGuiConsole() {
addOutput("McRogueFace Python Console", false);
addOutput("Type Python commands and press Enter to execute.", false);
addOutput("", false);
}
void ImGuiConsole::toggle() {
if (enabled) {
visible = !visible;
if (visible) {
// Focus input when opening
ImGui::SetWindowFocus("Console");
}
}
}
bool ImGuiConsole::wantsKeyboardInput() const {
return visible && enabled;
}
void ImGuiConsole::addOutput(const std::string& text, bool isError) {
// Split text by newlines and add each line separately
std::istringstream stream(text);
std::string line;
while (std::getline(stream, line)) {
outputHistory.push_back({line, isError, false});
}
// Trim history if too long
while (outputHistory.size() > MAX_HISTORY) {
outputHistory.pop_front();
}
scrollToBottom = true;
}
void ImGuiConsole::executeCommand(const std::string& command) {
if (command.empty()) return;
// Add command to output with >>> prefix
outputHistory.push_back({">>> " + command, false, true});
// Add to command history
commandHistory.push_back(command);
historyIndex = -1;
// Capture Python output
// Redirect stdout/stderr to capture output
std::string captureCode = R"(
import sys
import io
_console_stdout = io.StringIO()
_console_stderr = io.StringIO()
_old_stdout = sys.stdout
_old_stderr = sys.stderr
sys.stdout = _console_stdout
sys.stderr = _console_stderr
)";
std::string restoreCode = R"(
sys.stdout = _old_stdout
sys.stderr = _old_stderr
_stdout_val = _console_stdout.getvalue()
_stderr_val = _console_stderr.getvalue()
)";
// Set up capture
PyRun_SimpleString(captureCode.c_str());
// Try to evaluate as expression first (for things like "2+2")
PyObject* main_module = PyImport_AddModule("__main__");
PyObject* main_dict = PyModule_GetDict(main_module);
// First try eval (for expressions that return values)
PyObject* result = PyRun_String(command.c_str(), Py_eval_input, main_dict, main_dict);
bool showedResult = false;
if (result == nullptr) {
// Clear the error from eval attempt
PyErr_Clear();
// Try exec (for statements)
result = PyRun_String(command.c_str(), Py_file_input, main_dict, main_dict);
if (result == nullptr) {
// Real error - capture it
PyErr_Print(); // This prints to stderr which we're capturing
}
} else if (result != Py_None) {
// Expression returned a non-None value - show its repr
PyObject* repr = PyObject_Repr(result);
if (repr) {
const char* repr_str = PyUnicode_AsUTF8(repr);
if (repr_str) {
addOutput(repr_str, false);
showedResult = true;
}
Py_DECREF(repr);
}
}
Py_XDECREF(result);
// Restore stdout/stderr
PyRun_SimpleString(restoreCode.c_str());
// Get captured stdout (only if we didn't already show a result)
PyObject* stdout_val = PyObject_GetAttrString(main_module, "_stdout_val");
if (stdout_val && PyUnicode_Check(stdout_val)) {
const char* stdout_str = PyUnicode_AsUTF8(stdout_val);
if (stdout_str && strlen(stdout_str) > 0) {
addOutput(stdout_str, false);
}
}
Py_XDECREF(stdout_val);
// Get captured stderr
PyObject* stderr_val = PyObject_GetAttrString(main_module, "_stderr_val");
if (stderr_val && PyUnicode_Check(stderr_val)) {
const char* stderr_str = PyUnicode_AsUTF8(stderr_val);
if (stderr_str && strlen(stderr_str) > 0) {
addOutput(stderr_str, true);
}
}
Py_XDECREF(stderr_val);
// Clean up temporary variables
PyRun_SimpleString("del _console_stdout, _console_stderr, _old_stdout, _old_stderr, _stdout_val, _stderr_val");
scrollToBottom = true;
}
void ImGuiConsole::render() {
if (!visible || !enabled) return;
// Set up console window
ImGuiIO& io = ImGui::GetIO();
ImGui::SetNextWindowSize(ImVec2(io.DisplaySize.x, io.DisplaySize.y * 0.4f), ImGuiCond_FirstUseEver);
ImGui::SetNextWindowPos(ImVec2(0, 0), ImGuiCond_FirstUseEver);
ImGuiWindowFlags flags = ImGuiWindowFlags_NoCollapse;
if (!ImGui::Begin("Console", &visible, flags)) {
ImGui::End();
return;
}
// Output area (scrollable, no horizontal scrollbar - use word wrap)
float footerHeight = ImGui::GetStyle().ItemSpacing.y + ImGui::GetFrameHeightWithSpacing();
ImGui::BeginChild("ScrollingRegion", ImVec2(0, -footerHeight), false, ImGuiWindowFlags_None);
// Render output lines with word wrap
for (const auto& line : outputHistory) {
if (line.isInput) {
// User input - yellow/gold color
ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 0.9f, 0.4f, 1.0f));
} else if (line.isError) {
// Error - red color
ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 0.4f, 0.4f, 1.0f));
} else {
// Normal output - default color
ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.8f, 0.8f, 0.8f, 1.0f));
}
ImGui::TextWrapped("%s", line.text.c_str());
ImGui::PopStyleColor();
}
// Auto-scroll to bottom when new content is added
if (scrollToBottom || ImGui::GetScrollY() >= ImGui::GetScrollMaxY()) {
ImGui::SetScrollHereY(1.0f);
}
scrollToBottom = false;
ImGui::EndChild();
// Input line
ImGui::Separator();
// Input field
ImGuiInputTextFlags inputFlags = ImGuiInputTextFlags_EnterReturnsTrue |
ImGuiInputTextFlags_CallbackHistory |
ImGuiInputTextFlags_CallbackCompletion;
bool reclaimFocus = false;
// Custom callback for history navigation
auto callback = [](ImGuiInputTextCallbackData* data) -> int {
ImGuiConsole* console = static_cast<ImGuiConsole*>(data->UserData);
if (data->EventFlag == ImGuiInputTextFlags_CallbackHistory) {
if (console->commandHistory.empty()) return 0;
if (data->EventKey == ImGuiKey_UpArrow) {
if (console->historyIndex < 0) {
console->historyIndex = static_cast<int>(console->commandHistory.size()) - 1;
} else if (console->historyIndex > 0) {
console->historyIndex--;
}
} else if (data->EventKey == ImGuiKey_DownArrow) {
if (console->historyIndex >= 0) {
console->historyIndex++;
if (console->historyIndex >= static_cast<int>(console->commandHistory.size())) {
console->historyIndex = -1;
}
}
}
// Update input buffer
if (console->historyIndex >= 0 && console->historyIndex < static_cast<int>(console->commandHistory.size())) {
const std::string& historyEntry = console->commandHistory[console->historyIndex];
data->DeleteChars(0, data->BufTextLen);
data->InsertChars(0, historyEntry.c_str());
} else {
data->DeleteChars(0, data->BufTextLen);
}
}
return 0;
};
ImGui::PushItemWidth(-1); // Full width
if (ImGui::InputText("##Input", inputBuffer, sizeof(inputBuffer), inputFlags, callback, this)) {
std::string command(inputBuffer);
inputBuffer[0] = '\0';
executeCommand(command);
reclaimFocus = true;
}
ImGui::PopItemWidth();
// Keep focus on input
ImGui::SetItemDefaultFocus();
if (reclaimFocus || (visible && !ImGui::IsAnyItemActive())) {
ImGui::SetKeyboardFocusHere(-1);
}
ImGui::End();
}