From fdc116e402e8691cf841eb9a26df673be36c9191 Mon Sep 17 00:00:00 2001
From: Scott Moreau <oreaus@gmail.com>
Date: Tue, 16 Dec 2025 07:37:01 -0700
Subject: [PATCH] extra-animations: Add magic carpet animation

---
 metadata/extra-animations.xml   |  29 +++
 src/extra-animations/carpet.hpp | 439 ++++++++++++++++++++++++++++++++
 src/extra-animations/plugin.cpp |   7 +
 3 files changed, 475 insertions(+)
 create mode 100644 src/extra-animations/carpet.hpp

diff --git a/metadata/extra-animations.xml b/metadata/extra-animations.xml
index 272800a..86e49c8 100644
--- a/metadata/extra-animations.xml
+++ b/metadata/extra-animations.xml
@@ -126,6 +126,35 @@
 				<default>1.00 0.33 0.16 1.00</default>
 			</option>
 		</group>
+		<group>
+			<_short>Magic Carpet Settings</_short>
+			<option name="carpet_duration" type="animation">
+				<_short>Magic carpet duration</_short>
+				<_long>Sets the duration for the magic carpet animation in milliseconds.</_long>
+				<default>1000ms linear</default>
+			</option>
+			<option name="carpet_direction" type="int">
+				<_short>Carpet Direction</_short>
+				<_long>From which side to unroll the carpet for the open animation. The opposite direction will be used on close animation.</_long>
+				<default>0</default>
+				<desc>
+					<value>0</value>
+					<_name>Left</_name>
+				</desc>
+				<desc>
+					<value>1</value>
+					<_name>Right</_name>
+				</desc>
+				<desc>
+					<value>2</value>
+					<_name>Top</_name>
+				</desc>
+				<desc>
+					<value>3</value>
+					<_name>Bottom</_name>
+				</desc>
+			</option>
+		</group>
 		<group>
 			<_short>Dodge Settings</_short>
 			<option name="dodge_toggle" type="bool">
diff --git a/src/extra-animations/carpet.hpp b/src/extra-animations/carpet.hpp
new file mode 100644
index 0000000..07d3c95
--- /dev/null
+++ b/src/extra-animations/carpet.hpp
@@ -0,0 +1,439 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Scott Moreau <oreaus@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <wayfire/core.hpp>
+#include <wayfire/opengl.hpp>
+#include <wayfire/view-transform.hpp>
+#include <wayfire/util/duration.hpp>
+#include <wayfire/plugins/animate/animate.hpp>
+
+
+static const char *carpet_vert_source =
+    R"(
+#version 100
+
+attribute highp vec2 position;
+attribute highp vec2 uv_in;
+
+varying highp vec2 uvpos_var;
+
+void main() {
+
+    gl_Position = vec4(position.xy, 0.0, 1.0);
+    uvpos_var = uv_in;
+}
+)";
+
+static const char *carpet_frag_source =
+    R"(
+#version 100
+@builtin_ext@
+@builtin@
+
+precision highp float;
+
+varying highp vec2 uvpos_var;
+
+uniform float progress;
+uniform int direction;
+
+#define M_PI 3.1415926535897932384626433832795
+
+void main()
+{
+    vec4 wfrag;
+    vec2 uv;
+    vec2 uvpos;
+    if (direction == 1) // right
+    {
+        uvpos = vec2(1.0 - uvpos_var.x, uvpos_var.y);
+    } else if (direction == 2) // top
+    {
+        uvpos = vec2(1.0 - uvpos_var.y, uvpos_var.x);
+    } else if (direction == 3) // bottom
+    {
+        uvpos = vec2(uvpos_var.y, uvpos_var.x);
+    } else // left
+    {
+        uvpos = uvpos_var;
+    }
+    float offset = 0.1;
+    float p = progress * 1.2 - 0.2;
+
+    // initial color (transparent)
+    wfrag = vec4(0.0);
+    // get pixel from default position if left of peel line
+    if (uvpos.x < p + offset + 0.05)
+    {
+        if (uvpos_var.x >= 0.0 && uvpos_var.x <= 1.0 &&
+            uvpos_var.y >= 0.0 && uvpos_var.y <= 1.0)
+        {
+            // sample the texture, but only if within 0-1 range to avoid clamping
+            wfrag = get_pixel(uvpos_var);
+        }
+    }
+    // back of roll
+    if (uvpos.x > p + offset + 0.05 && uvpos.x < p + offset + 0.1)
+    {
+        // trigonometric sine
+        float tsin = (uvpos.x - (p + offset + 0.05)) * 20.0;
+        // angle from arcsine
+        float angle = asin(tsin);
+        // compute x sampling coordinate
+        if (direction == 0 || direction == 1)
+        {
+            uv.x = (angle / (M_PI)) * 0.15 + p + offset + 0.05;
+        } else
+        {
+            uv.x = (uvpos.y - 0.5) * pow(cos(angle), 0.02) + 0.5;
+        }
+        // compute y sampling coordinate
+        if (direction == 2 || direction == 3)
+        {
+            uv.y = (angle / (M_PI)) * 0.15 + p + offset + 0.05;
+        } else
+        {
+            uv.y = (uvpos.y - 0.5) * pow(cos(angle), 0.02) + 0.5;
+        }
+        vec4 pfrag = vec4(0.0);
+        if (uv.x >= 0.0 && uv.x <= 1.0 &&
+            uv.y >= 0.0 && uv.y <= 1.0)
+        {
+            // sample the texture, but only if within 0-1 range to avoid clamping
+            if (direction == 1)
+            {
+                pfrag = get_pixel(vec2(1.0 - uv.x, uv.y));
+			} else if (direction == 2)
+            {
+                pfrag = get_pixel(vec2(uv.x, 1.0 - uv.y));
+			} else
+            {
+                pfrag = get_pixel(uv);
+			}
+        }
+        // store color for fragment mixing with current fragment if translucent
+        wfrag = mix(pfrag, wfrag, wfrag.a);
+    }
+    // front of roll
+    if (uvpos.x > p + offset && uvpos.x < p + offset + 0.1)
+    {
+        // trigonometric sine
+        float tsin = (uvpos.x - (p + offset + 0.1)) * 20.0 + 1.0;
+        // angle from arcsine
+        float angle = asin(tsin);
+        // compute x sampling coordinate
+        if (direction == 0 || direction == 1)
+        {
+            uv.x = (angle / (-M_PI)) * 0.1 + p + offset + 0.2;
+        } else
+        {
+            uv.x = (uvpos.y - 0.5) * 0.9 * pow(cos(angle), -0.04) + 0.5;
+        }
+        // compute y sampling coordinate
+        if (direction == 2 || direction == 3)
+        {
+            uv.y = (angle / (-M_PI)) * 0.1 + p + offset + 0.2;
+        } else
+        {
+            uv.y = (uvpos.y - 0.5) * 0.9 * pow(cos(angle), -0.04) + 0.5;
+        }
+        vec4 pfrag = vec4(0.0);
+        if (uv.x >= 0.0 && uv.x <= 1.0 &&
+            uv.y >= 0.0 && uv.y <= 1.0)
+        {
+            // sample the texture, but only if within 0-1 range to avoid clamping
+            if (direction == 1)
+            {
+                pfrag = get_pixel(vec2(1.0 - uv.x, uv.y));
+			} else if (direction == 2)
+            {
+                pfrag = get_pixel(vec2(uv.x, 1.0 - uv.y));
+			} else
+            {
+                pfrag = get_pixel(uv);
+			}
+        }
+        // compute lighting
+        pfrag = vec4(clamp(pfrag.rgb + (angle / -M_PI), 0.0, 1.0), pfrag.a);
+        // store color for fragment mixing with current fragment if translucent
+        wfrag = mix(wfrag, pfrag, pfrag.a);
+    }
+
+    gl_FragColor = wfrag;
+}
+)";
+
+namespace wf
+{
+namespace carpet
+{
+using namespace wf::scene;
+using namespace wf::animate;
+using namespace wf::animation;
+
+static std::string carpet_transformer_name = "animation-carpet";
+
+wf::option_wrapper_t<int> carpet_direction{"extra-animations/carpet_direction"};
+
+class carpet_transformer : public wf::scene::view_2d_transformer_t
+{
+  public:
+    wayfire_view view;
+    wf::output_t *output;
+    OpenGL::program_t program;
+    wf::auxilliary_buffer_t buffer;
+    duration_t progression;
+
+    class simple_node_render_instance_t : public wf::scene::transformer_render_instance_t<transformer_base_node_t>
+    {
+        wf::signal::connection_t<node_damage_signal> on_node_damaged =
+            [=] (node_damage_signal *ev)
+        {
+            push_to_parent(ev->region);
+        };
+
+        carpet_transformer *self;
+        wayfire_view view;
+        damage_callback push_to_parent;
+
+      public:
+        simple_node_render_instance_t(carpet_transformer *self, damage_callback push_damage,
+            wayfire_view view) : wf::scene::transformer_render_instance_t<transformer_base_node_t>(self,
+                push_damage,
+                view->get_output())
+        {
+            this->self = self;
+            this->view = view;
+            this->push_to_parent = push_damage;
+            self->connect(&on_node_damaged);
+        }
+
+        ~simple_node_render_instance_t()
+        {}
+
+        void schedule_instructions(
+            std::vector<render_instruction_t>& instructions,
+            const wf::render_target_t& target, wf::region_t& damage) override
+        {
+            instructions.push_back(render_instruction_t{
+                        .instance = this,
+                        .target   = target,
+                        .damage   = damage & self->get_bounding_box(),
+                    });
+        }
+
+        void transform_damage_region(wf::region_t& damage) override
+        {
+            damage |= self->get_bounding_box();
+        }
+
+        void render(const wf::scene::render_instruction_t& data) override
+        {
+            auto bb  = self->get_children_bounding_box();
+            auto pbb = self->get_padded_bounding_box();
+            auto tex = wf::gles_texture_t{get_texture(1.0)};
+
+            const float vertices[] = {
+                -1.0, -1.0,
+                1.0f, -1.0,
+                1.0f, 1.0f,
+                -1.0, 1.0f
+            };
+            wf::pointf_t offset1{-float(bb.x - pbb.x) / bb.width,
+                -float(pbb.height - ((bb.y - pbb.y) + bb.height)) / bb.height};
+            wf::pointf_t offset2{float(pbb.width) / bb.width + offset1.x,
+                float(pbb.height) / bb.height + offset1.y};
+            const float uv[] = {
+                float(offset1.x), float(offset2.y),
+                float(offset2.x), float(offset2.y),
+                float(offset2.x), float(offset1.y),
+                float(offset1.x), float(offset1.y),
+            };
+            auto progress = self->progression.progress();
+
+            data.pass->custom_gles_subpass([&]
+            {
+                self->buffer.allocate({pbb.width, pbb.height});
+                wf::gles::bind_render_buffer(self->buffer.get_renderbuffer());
+                wf::gles_texture_t final_tex{self->buffer.get_texture()};
+                OpenGL::clear(wf::color_t{0.0, 0.0, 0.0, 0.0}, GL_COLOR_BUFFER_BIT);
+                self->program.use(wf::TEXTURE_TYPE_RGBA);
+                self->program.attrib_pointer("position", 2, 0, vertices);
+                self->program.attrib_pointer("uv_in", 2, 0, uv);
+                self->program.uniform1f("progress", progress);
+                self->program.uniform1i("direction", carpet_direction);
+
+                self->program.set_active_texture(tex);
+                GL_CALL(glDrawArrays(GL_TRIANGLE_FAN, 0, 4));
+
+                wf::gles::bind_render_buffer(data.target);
+                for (auto box : data.damage)
+                {
+                    wf::gles::render_target_logic_scissor(data.target, wlr_box_from_pixman_box(box));
+                    OpenGL::render_transformed_texture(final_tex, pbb,
+                        wf::gles::render_target_orthographic_projection(data.target),
+                        glm::vec4(1.0, 1.0, 1.0, 1.0), 0);
+                }
+
+                GL_CALL(glBindTexture(GL_TEXTURE_2D, 0));
+                self->program.deactivate();
+                self->buffer.free();
+            });
+        }
+    };
+
+    carpet_transformer(wayfire_view view, wf::geometry_t bbox,
+        wf::animation_description_t duration) : wf::scene::view_2d_transformer_t(view)
+    {
+        this->view = view;
+        this->progression = duration_t{wf::create_option(duration)};
+        if (view->get_output())
+        {
+            output = view->get_output();
+            output->render->add_effect(&pre_hook, wf::OUTPUT_EFFECT_PRE);
+        }
+
+        wf::gles::run_in_context([&]
+        {
+            program.compile(carpet_vert_source, carpet_frag_source);
+        });
+    }
+
+    wf::geometry_t get_padded_bounding_box()
+    {
+        auto box     = this->get_children_bounding_box();
+        auto padding = (box.width > box.height ? box.width : box.height) * 0.07;
+        box.x     -= padding;
+        box.y     -= padding;
+        box.width += padding * 2;
+        box.height += padding * 2;
+        return box;
+    }
+
+    wf::geometry_t get_bounding_box() override
+    {
+        return get_padded_bounding_box();
+    }
+
+    wf::effect_hook_t pre_hook = [=] ()
+    {
+        output->render->damage(this->get_bounding_box());
+    };
+
+    void gen_render_instances(std::vector<render_instance_uptr>& instances,
+        damage_callback push_damage, wf::output_t *shown_on) override
+    {
+        instances.push_back(std::make_unique<simple_node_render_instance_t>(
+            this, push_damage, view));
+    }
+
+    void init_animation(bool carpet)
+    {
+        if (carpet)
+        {
+            this->progression.reverse();
+        }
+
+        this->progression.start();
+    }
+
+    virtual ~carpet_transformer()
+    {
+        if (output)
+        {
+            output->render->rem_effect(&pre_hook);
+        }
+
+        wf::gles::run_in_context_if_gles([&]
+        {
+            program.free_resources();
+        });
+    }
+};
+
+class carpet_animation : public animation_base_t
+{
+    wayfire_view view;
+
+  public:
+    void init(wayfire_view view, wf::animation_description_t dur, animation_type type) override
+    {
+        this->view = view;
+        pop_transformer(view);
+        auto bbox = view->get_transformed_node()->get_bounding_box();
+        auto tmgr = view->get_transformed_node();
+        auto node = std::make_shared<carpet_transformer>(view, bbox, dur);
+        tmgr->add_transformer(node, wf::TRANSFORMER_HIGHLEVEL + 1, carpet_transformer_name);
+        node->init_animation(type & WF_ANIMATE_HIDING_ANIMATION);
+    }
+
+    void pop_transformer(wayfire_view view)
+    {
+        if (view->get_transformed_node()->get_transformer(carpet_transformer_name))
+        {
+            view->get_transformed_node()->rem_transformer(carpet_transformer_name);
+        }
+    }
+
+    bool step() override
+    {
+        if (!view)
+        {
+            return false;
+        }
+
+        auto tmgr = view->get_transformed_node();
+        if (!tmgr)
+        {
+            return false;
+        }
+
+        if (auto tr =
+                tmgr->get_transformer<wf::carpet::carpet_transformer>(carpet_transformer_name))
+        {
+            auto running = tr->progression.running();
+            if (!running)
+            {
+                pop_transformer(view);
+                return false;
+            }
+
+            return running;
+        }
+
+        return false;
+    }
+
+    void reverse() override
+    {
+        if (auto tr =
+                view->get_transformed_node()->get_transformer<wf::carpet::carpet_transformer>(
+                    carpet_transformer_name))
+        {
+            tr->progression.reverse();
+        }
+    }
+};
+}
+}
diff --git a/src/extra-animations/plugin.cpp b/src/extra-animations/plugin.cpp
index f5dcc28..8ad8625 100644
--- a/src/extra-animations/plugin.cpp
+++ b/src/extra-animations/plugin.cpp
@@ -34,6 +34,7 @@
 #include "melt.hpp"
 #include "dodge.hpp"
 #include "burn.hpp"
+#include "carpet.hpp"
 
 class wayfire_extra_animations : public wf::plugin_interface_t
 {
@@ -45,6 +46,7 @@ class wayfire_extra_animations : public wf::plugin_interface_t
     wf::option_wrapper_t<wf::animation_description_t> vortex_duration{"extra-animations/vortex_duration"};
     wf::option_wrapper_t<wf::animation_description_t> melt_duration{"extra-animations/melt_duration"};
     wf::option_wrapper_t<wf::animation_description_t> burn_duration{"extra-animations/burn_duration"};
+    wf::option_wrapper_t<wf::animation_description_t> carpet_duration{"extra-animations/carpet_duration"};
     std::unique_ptr<wf::dodge::wayfire_dodge> dodge_plugin;
 
   public:
@@ -80,6 +82,10 @@ class wayfire_extra_animations : public wf::plugin_interface_t
             .generator = [] { return std::make_unique<wf::burn::burn_animation>(); },
             .default_duration = [=] { return burn_duration.value(); },
         });
+        effects_registry->register_effect("carpet", wf::animate::effect_description_t{
+            .generator = [] { return std::make_unique<wf::carpet::carpet_animation>(); },
+            .default_duration = [=] { return carpet_duration.value(); },
+        });
         dodge_toggle.set_callback([=] {dodge_option_changed();});
         dodge_option_changed();
     }
@@ -105,6 +111,7 @@ class wayfire_extra_animations : public wf::plugin_interface_t
         effects_registry->unregister_effect("vortex");
         effects_registry->unregister_effect("melt");
         effects_registry->unregister_effect("burn");
+        effects_registry->unregister_effect("carpet");
 
         if (dodge_plugin)
         {