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Merged
merged 4 commits into from
May 6, 2025
Merged

speedy windows cursor position query #55

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5b0b556
refactor(win): console buf info will be used more than once
jarjk May 6, 2025
211347d
perf(win): cursor position query has a significantly faster alternati…
jarjk May 6, 2025
f737712
refactor(win): clangd suggestions
jarjk May 6, 2025
7f00693
misc(examples): add cursor position query speed test
jarjk May 6, 2025
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34 changes: 34 additions & 0 deletions examples/cursor-position-query.cpp
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Original file line number Diff line number Diff line change
@@ -0,0 +1,34 @@
#include "../tui.hpp"
#include <cassert>
#include <chrono>
#include <cstdint>
// #include <thread>

// returns how much the queries altogether took in ns
uint64_t get_cursor_pos_n(const unsigned n) {
auto start = std::chrono::high_resolution_clock::now();
for (auto i = 0; i < n; ++i) {
// std::cout << "getting cursor position...\n";
auto cursor_pos = tui::cursor::get_position();
// std::cout << "cursor @ {" << cursor_pos.first << ", " << cursor_pos.second << "}\n";
// assert(cursor_pos == cursor_pos_tty);
// std::this_thread::sleep_for(std::chrono::milliseconds(800));
}
auto end = std::chrono::high_resolution_clock::now();
return std::chrono::duration_cast<std::chrono::nanoseconds>(end - start).count();
}

int main(int argc, char** argv) {
tui::enable_raw_mode();

unsigned n = 8;
if (argc > 1) {
n = std::stoi(argv[1]);
}

auto query_t_sum = get_cursor_pos_n(n);
// std::this_thread::sleep_for(std::chrono::seconds(8));
tui::disable_raw_mode();
std::cout << "getting cursor " << n << " times took: " << query_t_sum / 1000000 << "ms, avg: " << query_t_sum / n <<"ns\n";
return 0;
}
61 changes: 39 additions & 22 deletions tui.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,6 @@

#ifdef _WIN32 // windows

#include <wchar.h>
#include <windows.h>

#else // not windows
Expand All @@ -20,7 +19,6 @@
#include <cassert>
#include <cstdint>
#include <iostream>
#include <ostream>
#include <sstream>
#include <string>
#include <utility> // for std::pair
Expand Down Expand Up @@ -60,7 +58,7 @@ namespace tui {
exit(1); \
} \
DWORD mode; \
if (!GetConsoleMode(hStdin, &mode)) { \
if (GetConsoleMode(hStdin, &mode) == 0) { \
std::cerr << "error getting the console mode\n"; \
exit(1); \
}
Expand All @@ -73,7 +71,7 @@ namespace tui {
DWORD newMode = mode;
newMode &= ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT | ENABLE_PROCESSED_INPUT);

if (!SetConsoleMode(hStdin, newMode)) {
if (SetConsoleMode(hStdin, newMode) == 0) {
std::cerr << "error setting the console to raw mode\n";
exit(1);
}
Expand Down Expand Up @@ -102,7 +100,7 @@ namespace tui {

// Restore original mode
mode |= (ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT | ENABLE_PROCESSED_INPUT);
if (!SetConsoleMode(hStdin, mode)) {
if (SetConsoleMode(hStdin, mode) == 0) {
std::cerr << "error restoring the console mode\n";
exit(1);
}
Expand All @@ -124,6 +122,27 @@ namespace tui {

#undef win_setup

#ifdef _WIN32
inline CONSOLE_SCREEN_BUFFER_INFO get_console_buf_info() {
HANDLE console = nullptr;
CONSOLE_SCREEN_BUFFER_INFO info;
// create a handle to the console screen
console = CreateFileW(L"CONOUT$", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
OPEN_EXISTING, 0, nullptr);
if (console == INVALID_HANDLE_VALUE) {
std::cerr << "couldn't get console handle\n";
exit(1);
}
// calculate the size of the console window
if (GetConsoleScreenBufferInfo(console, &info) == 0) {
std::cerr << "couldn't get console screen buffer info\n";
exit(1);
}
CloseHandle(console);
return info;
}
#endif

namespace cursor {
// template for moving cursor
// moves cursor `n` times to `dir`
Expand Down Expand Up @@ -161,8 +180,17 @@ namespace tui {
// tell the terminal to check where the cursor is
csi_fn(query_position, "6n");

#ifdef _WIN32
// returns: (rows;cols)
inline std::pair<unsigned, unsigned> get_position() {
auto info = get_console_buf_info();
auto rows = info.dwCursorPosition.X + 1;
auto cols = info.dwCursorPosition.Y + 1;
return {rows, cols};
}
#else
// returns: (rows;cols)
// WARN: can be quite slow, don't use on eg. every screen update!
// NOTE: can take a while (eg 16ms) on (relatively) slow terminals
inline std::pair<unsigned, unsigned> get_position() {
query_position();
std::flush(std::cout);
Expand All @@ -179,6 +207,8 @@ namespace tui {

return {rows, cols};
}
#endif

} // namespace cursor

namespace screen {
Expand All @@ -204,22 +234,9 @@ namespace tui {
// returns: (rows;cols)/(y;x)
inline std::pair<unsigned, unsigned> size() {
#ifdef _WIN32
HANDLE console;
CONSOLE_SCREEN_BUFFER_INFO info;
short rows;
short columns;
// create a handle to the console screen
console = CreateFileW(L"CONOUT$", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
OPEN_EXISTING, 0, NULL);
if (console == INVALID_HANDLE_VALUE)
return {0, 0};

// calculate the size of the console window
if (GetConsoleScreenBufferInfo(console, &info) == 0)
return {0, 0};
CloseHandle(console);
columns = info.srWindow.Right - info.srWindow.Left + 1;
rows = info.srWindow.Bottom - info.srWindow.Top + 1;
auto info = get_console_buf_info();
int columns = info.srWindow.Right - info.srWindow.Left + 1;
int rows = info.srWindow.Bottom - info.srWindow.Top + 1;

return {rows, columns};
#else
Expand Down