hypr-dynamic-cursors/src/cursor.cpp

#include "globals.hpp"

#include <chrono>
#include <cmath>
#include <cstdlib>

#define private public
#include <hyprland/src/managers/PointerManager.hpp>
#include <hyprland/src/render/OpenGL.hpp>
#include <hyprland/src/Compositor.hpp>
#undef private

#include <hyprland/src/config/ConfigValue.hpp>
#include "hyprland/cursor.hpp"

#include <hyprland/wlr/interfaces/wlr_output.h>
#include <hyprland/wlr/render/interface.h>
#include <hyprland/wlr/render/wlr_renderer.h>

#include "cursor.hpp"
#include "renderer.hpp"

/*
Reimplements rendering of the software cursor.
Is also largely identical to hyprlands impl, but uses our custom rendering to rotate the cursor.
*/
void CDynamicCursors::renderSoftware(CPointerManager* pointers, SP<CMonitor> pMonitor, timespec* now, CRegion& damage, std::optional<Vector2D> overridePos) {

    if (!pointers->hasCursor())
        return;

    auto state = pointers->stateFor(pMonitor);

    if ((!state->hardwareFailed && state->softwareLocks == 0)) {
        return;
    }

    auto box = state->box.copy();
    if (overridePos.has_value()) {
        box.x = overridePos->x;
        box.y = overridePos->y;
    }

    if (box.intersection(CBox{{}, {pMonitor->vecSize}}).empty())
        return;

    auto texture = pointers->getCurrentCursorTexture();
    if (!texture)
        return;

    box.scale(pMonitor->scale);

    // we rotate the cursor by our calculated amount
    box.rot = this->calculate(&pointers->pointerPos);

    // now pass the hotspot to rotate around
    renderCursorTextureInternalWithDamage(texture, &box, &damage, 1.F, pointers->currentCursorImage.hotspot);
}

/*
This function implements damaging the screen such that the software cursor is drawn.
It is largely identical to hyprlands implementation, but expands the damage reagion, to accomodate various rotations.
*/
void CDynamicCursors::damageSoftware(CPointerManager* pointers) {

    // we damage a 3x3 area around the cursor, to accomodate for all possible hotspots and rotations
    Vector2D size = pointers->currentCursorImage.size / pointers->currentCursorImage.scale;
    CBox b = CBox{pointers->pointerPos, size * 3}.translate(-(pointers->currentCursorImage.hotspot + size));

    static auto PNOHW = CConfigValue<Hyprlang::INT>("cursor:no_hardware_cursors");

    for (auto& mw : pointers->monitorStates) {
        if (mw->monitor.expired())
            continue;

        if ((mw->softwareLocks > 0 || mw->hardwareFailed || *PNOHW) && b.overlaps({mw->monitor->vecPosition, mw->monitor->vecSize})) {
            g_pHyprRenderer->damageBox(&b, mw->monitor->shouldSkipScheduleFrameOnMouseEvent());
            break;
        }
    }
}

/*
This function reimplements the hardware cursor buffer drawing.
It is largely copied from hyprland, but adjusted to allow the cursor to be rotated.
*/
wlr_buffer* CDynamicCursors::renderHardware(CPointerManager* pointers, SP<CPointerManager::SMonitorPointerState> state, SP<CTexture> texture) {
    static auto* const* PHW_DEBUG= (Hyprlang::INT* const*)HyprlandAPI::getConfigValue(PHANDLE, CONFIG_HW_DEBUG)->getDataStaticPtr();

    auto output = state->monitor->output;

    auto size = pointers->currentCursorImage.size;
    // we try to allocate a buffer that is thrice as big, see software rendering
    auto target = size * 3;

    if (output->impl->get_cursor_size) {
        int w, h;
        output->impl->get_cursor_size(output, &w, &h);

        if (w < target.x || h < target.y) {
            Debug::log(TRACE, "hardware cursor too big! {} > {}x{}", pointers->currentCursorImage.size, w, h);
            return nullptr;
        }

        target.x = w;
        target.y = h;
    }

    if (target.x <= 0 || target.y <= 0) {
        Debug::log(TRACE, "hw cursor for output {} failed the size checks ({}x{} is invalid)", state->monitor->szName, target.x, target.y);
        return nullptr;
    }

    if (!output->cursor_swapchain || target != Vector2D{output->cursor_swapchain->width, output->cursor_swapchain->height}) {
        wlr_drm_format fmt = {0};
        if (!output_pick_cursor_format(output, &fmt)) {
            Debug::log(TRACE, "Failed to pick cursor format");
            return nullptr;
        }

        wlr_swapchain_destroy(output->cursor_swapchain);
        output->cursor_swapchain = wlr_swapchain_create(output->allocator, target.x, target.y, &fmt);
        wlr_drm_format_finish(&fmt);

        if (!output->cursor_swapchain) {
            Debug::log(TRACE, "Failed to create cursor swapchain");
            return nullptr;
        }
    }

    wlr_buffer* buf = wlr_swapchain_acquire(output->cursor_swapchain, nullptr);
    if (!buf) {
        Debug::log(TRACE, "Failed to acquire a buffer from the cursor swapchain");
        return nullptr;
    }

    CRegion damage = {0, 0, INT16_MAX, INT16_MAX};

    g_pHyprRenderer->makeEGLCurrent();
    g_pHyprOpenGL->m_RenderData.pMonitor = state->monitor.get(); // has to be set cuz allocs

    const auto RBO = g_pHyprRenderer->getOrCreateRenderbuffer(buf, DRM_FORMAT_ARGB8888);
    RBO->bind();

    g_pHyprOpenGL->beginSimple(state->monitor.get(), damage, RBO);

    if (**PHW_DEBUG)
        g_pHyprOpenGL->clear(CColor{rand() / float(RAND_MAX), rand() / float(RAND_MAX), rand() / float(RAND_MAX), 1.F});
    else
        g_pHyprOpenGL->clear(CColor{0.F, 0.F, 0.F, 0.F});

    // the box should start in the middle portion, rotate by our calculated amount
    CBox xbox = {size, Vector2D{pointers->currentCursorImage.size / pointers->currentCursorImage.scale * state->monitor->scale}.round()};
    xbox.rot = this->calculate(&pointers->pointerPos);

    //  use our custom draw function
    renderCursorTextureInternalWithDamage(texture, &xbox, &damage, 1.F, pointers->currentCursorImage.hotspot);

    g_pHyprOpenGL->end();
    glFlush();
    g_pHyprOpenGL->m_RenderData.pMonitor = nullptr;

    wlr_buffer_unlock(buf);

    return buf;
}

/*
Implements the hardware cursor setting.
It is also mostly the same as stock hyprland, but with the hotspot translated more into the middle.
*/
bool CDynamicCursors::setHardware(CPointerManager* pointers, SP<CPointerManager::SMonitorPointerState> state, wlr_buffer* buf) {
    if (!state->monitor->output->impl->set_cursor)
        return false;

    const auto HOTSPOT = pointers->transformedHotspot(state->monitor.lock());

    Debug::log(TRACE, "[pointer] hw transformed hotspot for {}: {}", state->monitor->szName, HOTSPOT);

    if (!state->monitor->output->impl->set_cursor(state->monitor->output, buf, HOTSPOT.x + pointers->currentCursorImage.size.x, HOTSPOT.y + pointers->currentCursorImage.size.y))
        return false;

    wlr_buffer_unlock(state->cursorFrontBuffer);
    state->cursorFrontBuffer = buf;

    g_pCompositor->scheduleFrameForMonitor(state->monitor.get());

    if (buf)
        wlr_buffer_lock(buf);

    return true;
}

/*
Handles cursor move events.
*/
void CDynamicCursors::onCursorMoved(CPointerManager* pointers) {
    if (!pointers->hasCursor())
        return;

    for (auto& m : g_pCompositor->m_vMonitors) {
        auto state = pointers->stateFor(m);

        state->box = pointers->getCursorBoxLogicalForMonitor(state->monitor.lock());

        if (state->hardwareFailed || !state->entered)
            continue;

        // we set a new hardware cursor on every move
        pointers->attemptHardwareCursor(state);
    }
}

double CDynamicCursors::calculate(Vector2D* pos) {
    static auto* const* PLENGTH = (Hyprlang::INT* const*)HyprlandAPI::getConfigValue(PHANDLE, CONFIG_LENGTH)->getDataStaticPtr();

    // translate to origin
    end.x -= pos->x;
    end.y -= pos->y;

    // normalize
    double size = end.size();
    end.x /= size;
    end.y /= size;

    // scale to length
    end.x *= **PLENGTH;
    end.y *= **PLENGTH;

    // calculate angle
    double angle = -atan(end.x / end.y);
    if (end.y > 0) angle += PI;
    angle += PI;

    // translate back
    end.x += pos->x;
    end.y += pos->y;

    return angle;
}