wp-fractional-scaling-v1 impl (#1373)

* Initial fractional scaling impl

* apply UV after geom calcs

* fix scaling -> scale

* meson: add fractional scale proto

Co-authored-by: Mihai Fufezan <fufexan@protonmail.com>

src/protocols/FractionalScale.cpp

@@ -0,0 +1,102 @@
+#include "FractionalScale.hpp"
+
+#include "../Compositor.hpp"
+
+#define FRACTIONAL_SCALE_VERSION 1
+
+static void bindManagerInt(wl_client* client, void* data, uint32_t version, uint32_t id) {
+    g_pProtocolManager->m_pFractionalScaleProtocolManager->bindManager(client, data, version, id);
+}
+
+static void handleDisplayDestroy(struct wl_listener* listener, void* data) {
+    g_pProtocolManager->m_pFractionalScaleProtocolManager->displayDestroy();
+}
+
+void CFractionalScaleProtocolManager::displayDestroy() {
+    wl_global_destroy(m_pGlobal);
+}
+
+static void handleDestroy(wl_client* client, wl_resource* resource) {
+    wl_resource_destroy(resource);
+}
+
+void handleGetFractionalScale(wl_client* client, wl_resource* resource, uint32_t id, wl_resource* surface) {
+    g_pProtocolManager->m_pFractionalScaleProtocolManager->getFractionalScale(client, resource, id, surface);
+}
+
+CFractionalScaleProtocolManager::CFractionalScaleProtocolManager() {
+    m_pGlobal = wl_global_create(g_pCompositor->m_sWLDisplay, &wp_fractional_scale_manager_v1_interface, FRACTIONAL_SCALE_VERSION, this, bindManagerInt);
+
+    if (!m_pGlobal) {
+        Debug::log(ERR, "FractionalScaleManager could not start! Fractional scaling will not work!");
+        return;
+    }
+
+    m_liDisplayDestroy.notify = handleDisplayDestroy;
+    wl_display_add_destroy_listener(g_pCompositor->m_sWLDisplay, &m_liDisplayDestroy);
+
+    Debug::log(LOG, "FractionalScaleManager started successfully!");
+}
+
+static const struct wp_fractional_scale_manager_v1_interface fractionalScaleManagerImpl = {
+    .destroy              = handleDestroy,
+    .get_fractional_scale = handleGetFractionalScale,
+};
+
+void CFractionalScaleProtocolManager::bindManager(wl_client* client, void* data, uint32_t version, uint32_t id) {
+    const auto RESOURCE = wl_resource_create(client, &wp_fractional_scale_manager_v1_interface, version, id);
+    wl_resource_set_implementation(RESOURCE, &fractionalScaleManagerImpl, this, nullptr);
+
+    Debug::log(LOG, "FractionalScaleManager bound successfully!");
+}
+
+void handleDestroyScaleAddon(wl_client* client, wl_resource* resource);
+//
+
+static const struct wp_fractional_scale_v1_interface fractionalScaleAddonImpl { .destroy = handleDestroyScaleAddon };
+
+//
+SFractionalScaleAddon* addonFromResource(wl_resource* resource) {
+    ASSERT(wl_resource_instance_of(resource, &wp_fractional_scale_v1_interface, &fractionalScaleAddonImpl));
+    return (SFractionalScaleAddon*)wl_resource_get_user_data(resource);
+}
+
+void handleDestroyScaleAddon(wl_client* client, wl_resource* resource) {
+    g_pProtocolManager->m_pFractionalScaleProtocolManager->removeAddon(addonFromResource(resource)->pSurface);
+    wl_resource_destroy(resource);
+}
+
+void CFractionalScaleProtocolManager::getFractionalScale(wl_client* client, wl_resource* resource, uint32_t id, wl_resource* surface) {
+    const auto PSURFACE = wlr_surface_from_resource(surface);
+    const auto PADDON   = getAddonForSurface(PSURFACE);
+
+    PADDON->pResource = wl_resource_create(client, &wp_fractional_scale_v1_interface, wl_resource_get_version(resource), id);
+
+    wp_fractional_scale_v1_send_preferred_scale(PADDON->pResource, (uint32_t)std::round(PADDON->preferredScale * 120.0));
+}
+
+SFractionalScaleAddon* CFractionalScaleProtocolManager::getAddonForSurface(wlr_surface* surface) {
+    const auto IT = std::find_if(m_vFractionalScaleAddons.begin(), m_vFractionalScaleAddons.end(), [&](const auto& other) { return other->pSurface == surface; });
+
+    if (IT != m_vFractionalScaleAddons.end())
+        return IT->get();
+
+    m_vFractionalScaleAddons.emplace_back(std::make_unique<SFractionalScaleAddon>());
+
+    m_vFractionalScaleAddons.back()->pSurface = surface;
+
+    return m_vFractionalScaleAddons.back().get();
+}
+
+void CFractionalScaleProtocolManager::setPreferredScaleForSurface(wlr_surface* surface, double scale) {
+    const auto PADDON = getAddonForSurface(surface);
+
+    PADDON->preferredScale = scale;
+
+    if (PADDON->pResource)
+        wp_fractional_scale_v1_send_preferred_scale(PADDON->pResource, (uint32_t)std::round(scale * 120.0));
+}
+
+void CFractionalScaleProtocolManager::removeAddon(wlr_surface* surface) {
+    std::erase_if(m_vFractionalScaleAddons, [&](const auto& other) { return other->pSurface == surface; });
+}