feat: rotate cursor around hotspot

src/cursor.cpp

@@ -0,0 +1,72 @@
+#include "globals.hpp"
+
+#include <cmath>
+
+#define private public
+#include <hyprland/src/managers/PointerManager.hpp>
+#include <hyprland/src/render/OpenGL.hpp>
+#undef private
+
+#include <hyprland/src/Compositor.hpp>
+#include <hyprland/src/config/ConfigValue.hpp>
+
+#include "cursor.hpp"
+#include "renderer.hpp"
+
+void CDynamicCursors::render(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);
+    box.rot = this->calculate(&pointers->pointerPos);
+
+    renderCursorTextureInternalWithDamage(texture, &box, &damage, 1.F, pointers->currentCursorImage.hotspot);
+}
+
+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;
+}