docs: add project README

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I6a6a696411e599829afb123a5f3c241768470163

.editorconfig

@@ -0,0 +1,33 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+
+[*.c]
+indent_style = space
+indent_size = 2
+tab_width = 2
+
+[*.h]
+indent_style = space
+indent_size = 2
+tab_width = 2
+
+[Makefile]
+indent_style = tab
+tab_width = 4
+trim_trailing_whitespace = false
+
+[*.mk]
+indent_style = tab
+tab_width = 4
+trim_trailing_whitespace = false
+
+[*.sh]
+indent_style = space
+indent_size = 2
+tab_width = 2
+

.envrc

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+use flake

.gitattributes

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+# Vendored headers are vendored code, to the surprise of absolutely noone.
+# See:
+# <https://github.com/github-linguist/linguist/blob/main/docs/overrides.md#vendored-code>
+/include/chroma.h linguist-vendored
+
+# Don't think linguist can detect XML, but let's tell it that the protocols are
+# vendored *anyway*.
+/protocols/*.xml  linguist-vendored

.gitignore

@@ -0,0 +1,8 @@
+/bin
+/obj
+
+# Generated by wayland-scanner
+include/xdg-shell.h
+include/wlr-layer-shell-unstable-v1.h
+src/xdg-shell.c
+src/wlr-layer-shell-unstable-v1.c

LICENSE

@@ -0,0 +1,328 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+    1.1. “Contributor”
+    means each individual or legal entity that creates, contributes to the
+    creation of, or owns Covered Software.
+
+    1.2. “Contributor Version”
+    means the combination of the Contributions of others (if any) used by a
+    Contributor and that particular Contributor’s Contribution.
+
+    1.3. “Contribution”
+    means Covered Software of a particular Contributor.
+
+    1.4. “Covered Software”
+    means Source Code Form to which the initial Contributor has attached the
+    notice in Exhibit A, the Executable Form of such Source Code Form,
+    and Modifications of such Source Code Form, in each case
+    including portions thereof.
+
+    1.5. “Incompatible With Secondary Licenses”
+    means
+
+        a. that the initial Contributor has attached the notice described
+        in Exhibit B to the Covered Software; or
+
+        b. that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the terms
+        of a Secondary License.
+
+    1.6. “Executable Form”
+    means any form of the work other than Source Code Form.
+
+    1.7. “Larger Work”
+    means a work that combines Covered Software with other material,
+    in a separate file or files, that is not Covered Software.
+
+    1.8. “License”
+    means this document.
+
+    1.9. “Licensable”
+    means having the right to grant, to the maximum extent possible,
+    whether at the time of the initial grant or subsequently,
+    any and all of the rights conveyed by this License.
+
+    1.10. “Modifications”
+    means any of the following:
+
+        a. any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered Software; or
+
+        b. any new file in Source Code Form that contains any Covered Software.
+
+    1.11. “Patent Claims” of a Contributor
+    means any patent claim(s), including without limitation, method, process,
+    and apparatus claims, in any patent Licensable by such Contributor that
+    would be infringed, but for the grant of the License, by the making,
+    using, selling, offering for sale, having made, import, or transfer of
+    either its Contributions or its Contributor Version.
+
+    1.12. “Secondary License”
+    means either the GNU General Public License, Version 2.0, the
+    GNU Lesser General Public License, Version 2.1, the GNU Affero General
+    Public License, Version 3.0, or any later versions of those licenses.
+
+    1.13. “Source Code Form”
+    means the form of the work preferred for making modifications.
+
+    1.14. “You” (or “Your”)
+    means an individual or a legal entity exercising rights under this License.
+    For legal entities, “You” includes any entity that controls,
+    is controlled by, or is under common control with You. For purposes of
+    this definition, “control” means (a) the power, direct or indirect,
+    to cause the direction or management of such entity, whether by contract
+    or otherwise, or (b) ownership of more than fifty percent (50%) of the
+    outstanding shares or beneficial ownership of such entity.
+
+2. License Grants and Conditions
+
+    2.1. Grants
+    Each Contributor hereby grants You a world-wide, royalty-free,
+    non-exclusive license:
+
+        a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications,
+        or as part of a Larger Work; and
+
+        b. under Patent Claims of such Contributor to make, use, sell,
+        offer for sale, have made, import, and otherwise transfer either
+        its Contributions or its Contributor Version.
+
+    2.2. Effective Date
+    The licenses granted in Section 2.1 with respect to any Contribution
+    become effective for each Contribution on the date the Contributor
+    first distributes such Contribution.
+
+    2.3. Limitations on Grant Scope
+    The licenses granted in this Section 2 are the only rights granted
+    under this License. No additional rights or licenses will be implied
+    from the distribution or licensing of Covered Software under this License.
+    Notwithstanding Section 2.1(b) above, no patent license is granted
+    by a Contributor:
+
+        a. for any code that a Contributor has removed from
+        Covered Software; or
+
+        b. for infringements caused by: (i) Your and any other third party’s
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its
+        Contributor Version); or
+
+        c. under Patent Claims infringed by Covered Software in the
+        absence of its Contributions.
+
+    This License does not grant any rights in the trademarks, service marks,
+    or logos of any Contributor (except as may be necessary to comply with
+    the notice requirements in Section 3.4).
+
+    2.4. Subsequent Licenses
+    No Contributor makes additional grants as a result of Your choice to
+    distribute the Covered Software under a subsequent version of this
+    License (see Section 10.2) or under the terms of a Secondary License
+    (if permitted under the terms of Section 3.3).
+
+    2.5. Representation
+    Each Contributor represents that the Contributor believes its
+    Contributions are its original creation(s) or it has sufficient rights
+    to grant the rights to its Contributions conveyed by this License.
+
+    2.6. Fair Use
+    This License is not intended to limit any rights You have under
+    applicable copyright doctrines of fair use, fair dealing,
+    or other equivalents.
+
+    2.7. Conditions
+    Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the
+    licenses granted in Section 2.1.
+
+3. Responsibilities
+
+    3.1. Distribution of Source Form
+    All distribution of Covered Software in Source Code Form, including
+    any Modifications that You create or to which You contribute, must be
+    under the terms of this License. You must inform recipients that the
+    Source Code Form of the Covered Software is governed by the terms
+    of this License, and how they can obtain a copy of this License.
+    You may not attempt to alter or restrict the recipients’ rights
+    in the Source Code Form.
+
+    3.2. Distribution of Executable Form
+    If You distribute Covered Software in Executable Form then:
+
+        a. such Covered Software must also be made available in Source Code
+        Form, as described in Section 3.1, and You must inform recipients of
+        the Executable Form how they can obtain a copy of such Source Code
+        Form by reasonable means in a timely manner, at a charge no more than
+        the cost of distribution to the recipient; and
+
+        b. You may distribute such Executable Form under the terms of this
+        License, or sublicense it under different terms, provided that the
+        license for the Executable Form does not attempt to limit or alter
+        the recipients’ rights in the Source Code Form under this License.
+
+    3.3. Distribution of a Larger Work
+    You may create and distribute a Larger Work under terms of Your choice,
+    provided that You also comply with the requirements of this License for
+    the Covered Software. If the Larger Work is a combination of
+    Covered Software with a work governed by one or more Secondary Licenses,
+    and the Covered Software is not Incompatible With Secondary Licenses,
+    this License permits You to additionally distribute such Covered Software
+    under the terms of such Secondary License(s), so that the recipient of
+    the Larger Work may, at their option, further distribute the
+    Covered Software under the terms of either this License or such
+    Secondary License(s).
+
+    3.4. Notices
+    You may not remove or alter the substance of any license notices
+    (including copyright notices, patent notices, disclaimers of warranty,
+    or limitations of liability) contained within the Source Code Form of
+    the Covered Software, except that You may alter any license notices to
+    the extent required to remedy known factual inaccuracies.
+
+    3.5. Application of Additional Terms
+    You may choose to offer, and to charge a fee for, warranty, support,
+    indemnity or liability obligations to one or more recipients of
+    Covered Software. However, You may do so only on Your own behalf,
+    and not on behalf of any Contributor. You must make it absolutely clear
+    that any such warranty, support, indemnity, or liability obligation is
+    offered by You alone, and You hereby agree to indemnify every Contributor
+    for any liability incurred by such Contributor as a result of warranty,
+    support, indemnity or liability terms You offer. You may include
+    additional disclaimers of warranty and limitations of liability
+    specific to any jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+If it is impossible for You to comply with any of the terms of this License
+with respect to some or all of the Covered Software due to statute,
+judicial order, or regulation then You must: (a) comply with the terms of
+this License to the maximum extent possible; and (b) describe the limitations
+and the code they affect. Such description must be placed in a text file
+included with all distributions of the Covered Software under this License.
+Except to the extent prohibited by statute or regulation, such description
+must be sufficiently detailed for a recipient of ordinary skill
+to be able to understand it.
+
+5. Termination
+
+    5.1. The rights granted under this License will terminate automatically
+    if You fail to comply with any of its terms. However, if You become
+    compliant, then the rights granted under this License from a particular
+    Contributor are reinstated (a) provisionally, unless and until such
+    Contributor explicitly and finally terminates Your grants, and (b) on an
+    ongoing basis, if such Contributor fails to notify You of the
+    non-compliance by some reasonable means prior to 60 days after You have
+    come back into compliance. Moreover, Your grants from a particular
+    Contributor are reinstated on an ongoing basis if such Contributor
+    notifies You of the non-compliance by some reasonable means,
+    this is the first time You have received notice of non-compliance with
+    this License from such Contributor, and You become compliant prior to
+    30 days after Your receipt of the notice.
+
+    5.2. If You initiate litigation against any entity by asserting a patent
+    infringement claim (excluding declaratory judgment actions,
+    counter-claims, and cross-claims) alleging that a Contributor Version
+    directly or indirectly infringes any patent, then the rights granted
+    to You by any and all Contributors for the Covered Software under
+    Section 2.1 of this License shall terminate.
+
+    5.3. In the event of termination under Sections 5.1 or 5.2 above, all
+    end user license agreements (excluding distributors and resellers) which
+    have been validly granted by You or Your distributors under this License
+    prior to termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+Covered Software is provided under this License on an “as is” basis, without
+warranty of any kind, either expressed, implied, or statutory, including,
+without limitation, warranties that the Covered Software is free of defects,
+merchantable, fit for a particular purpose or non-infringing. The entire risk
+as to the quality and performance of the Covered Software is with You.
+Should any Covered Software prove defective in any respect, You
+(not any Contributor) assume the cost of any necessary servicing, repair,
+or correction. This disclaimer of warranty constitutes an essential part of
+this License. No use of any Covered Software is authorized under this
+License except under this disclaimer.
+
+7. Limitation of Liability
+
+Under no circumstances and under no legal theory, whether tort
+(including negligence), contract, or otherwise, shall any Contributor, or
+anyone who distributes Covered Software as permitted above, be liable to
+You for any direct, indirect, special, incidental, or consequential damages
+of any character including, without limitation, damages for lost profits,
+loss of goodwill, work stoppage, computer failure or malfunction, or any and
+all other commercial damages or losses, even if such party shall have been
+informed of the possibility of such damages. This limitation of liability
+shall not apply to liability for death or personal injury resulting from
+such party’s negligence to the extent applicable law prohibits such
+limitation. Some jurisdictions do not allow the exclusion or limitation of
+incidental or consequential damages, so this exclusion and limitation may
+not apply to You.
+
+8. Litigation
+
+Any litigation relating to this License may be brought only in the courts of
+a jurisdiction where the defendant maintains its principal place of business
+and such litigation shall be governed by laws of that jurisdiction, without
+reference to its conflict-of-law provisions. Nothing in this Section shall
+prevent a party’s ability to bring cross-claims or counter-claims.
+
+9. Miscellaneous
+
+This License represents the complete agreement concerning the subject matter
+hereof. If any provision of this License is held to be unenforceable,
+such provision shall be reformed only to the extent necessary to make it
+enforceable. Any law or regulation which provides that the language of a
+contract shall be construed against the drafter shall not be used to construe
+this License against a Contributor.
+
+10. Versions of the License
+
+    10.1. New Versions
+    Mozilla Foundation is the license steward. Except as provided in
+    Section 10.3, no one other than the license steward has the right to
+    modify or publish new versions of this License. Each version will be
+    given a distinguishing version number.
+
+    10.2. Effect of New Versions
+    You may distribute the Covered Software under the terms of the version
+    of the License under which You originally received the Covered Software,
+    or under the terms of any subsequent version published
+    by the license steward.
+
+    10.3. Modified Versions
+    If you create software not governed by this License, and you want to
+    create a new license for such software, you may create and use a modified
+    version of this License if you rename the license and remove any
+    references to the name of the license steward (except to note that such
+    modified license differs from this License).
+
+    10.4. Distributing Source Code Form that is
+    Incompatible With Secondary Licenses
+    If You choose to distribute Source Code Form that is
+    Incompatible With Secondary Licenses under the terms of this version of
+    the License, the notice described in Exhibit B of this
+    License must be attached.
+
+Exhibit A - Source Code Form License Notice
+
+    This Source Code Form is subject to the terms of the
+    Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed
+    with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file,
+then You may include the notice in a location (such as a LICENSE file in a
+relevant directory) where a recipient would be likely to
+look for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - “Incompatible With Secondary Licenses” Notice
+
+    This Source Code Form is “Incompatible With Secondary Licenses”,
+    as defined by the Mozilla Public License, v. 2.0.

Makefile

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+PROJECT_NAME = chroma
+VERSION = 1.0.0
+
+# Directories
+SRCDIR = src
+INCDIR = include
+OBJDIR = obj
+BINDIR = bin
+SYSTEMD_DIR = systemd
+PROTOCOLDIR = protocols
+
+# Install directories
+PREFIX ?= /usr/local
+BINDIR_INSTALL = $(PREFIX)/bin
+SYSTEMD_INSTALL = $(HOME)/.config/systemd/user
+
+# Compiler and flags
+CC = gcc
+CFLAGS = -std=c11 -Wall -Wextra -Werror -pedantic -O2 -g
+CFLAGS += -D_GNU_SOURCE -DCHROMA_VERSION=\"$(VERSION)\"
+CPPFLAGS = -I$(INCDIR)
+
+# Debug build flags
+DEBUG_CFLAGS = -std=c11 -Wall -Wextra -Werror -pedantic -Og -g3 -DDEBUG
+DEBUG_CFLAGS += -D_GNU_SOURCE -DCHROMA_VERSION=\"$(VERSION)-debug\"
+DEBUG_CFLAGS += -fsanitize=address -fsanitize=undefined -fno-omit-frame-pointer
+
+# Libraries using pkg-config
+PKG_DEPS = wayland-client wayland-egl egl glesv2 wayland-protocols
+CFLAGS += $(shell pkg-config --cflags $(PKG_DEPS))
+LDFLAGS += $(shell pkg-config --libs $(PKG_DEPS))
+
+# Protocol files
+PROTOCOL_XML = $(PROTOCOLDIR)/xdg-shell.xml $(PROTOCOLDIR)/wlr-layer-shell-unstable-v1.xml
+PROTOCOL_HEADERS = $(PROTOCOL_XML:$(PROTOCOLDIR)/%.xml=$(INCDIR)/%.h)
+PROTOCOL_SOURCES = $(PROTOCOL_XML:$(PROTOCOLDIR)/%.xml=$(SRCDIR)/%.c)
+PROTOCOL_OBJECTS = $(PROTOCOL_SOURCES:$(SRCDIR)/%.c=$(OBJDIR)/%.o)
+
+# Additional libraries
+LDFLAGS += -lm -ldl
+
+# Source files (excluding generated protocol files)
+SOURCES = $(filter-out $(PROTOCOL_SOURCES), $(wildcard $(SRCDIR)/*.c))
+OBJECTS = $(SOURCES:$(SRCDIR)/%.c=$(OBJDIR)/%.o) $(PROTOCOL_OBJECTS)
+DEPENDS = $(OBJECTS:.o=.d)
+
+# Default target
+TARGET = $(BINDIR)/$(PROJECT_NAME)
+all: $(TARGET)
+
+# Create directories
+$(OBJDIR):
+	@mkdir -p $(OBJDIR)
+
+$(BINDIR):
+	@mkdir -p $(BINDIR)
+
+# Protocol generation
+$(INCDIR)/%.h: $(PROTOCOLDIR)/%.xml | $(INCDIR)
+	@echo "  PROTO $<"
+	@wayland-scanner client-header $< $@
+
+$(SRCDIR)/%.c: $(PROTOCOLDIR)/%.xml
+	@echo "  PROTO $<"
+	@wayland-scanner private-code $< $@
+
+# Make sure include directory exists
+$(INCDIR):
+	@mkdir -p $(INCDIR)
+
+# Build main executable
+$(TARGET): $(PROTOCOL_HEADERS) $(OBJECTS) | $(BINDIR)
+	@echo "  LINK  $@"
+	@$(CC) $(OBJECTS) -o $@ $(LDFLAGS)
+
+# Compile source files
+$(OBJDIR)/%.o: $(SRCDIR)/%.c $(PROTOCOL_HEADERS) | $(OBJDIR)
+	@echo "  CC    $<"
+	@$(CC) $(CPPFLAGS) $(CFLAGS) -MMD -MP -c $< -o $@
+
+# Debug build
+debug: CFLAGS = $(DEBUG_CFLAGS)
+debug: $(TARGET)
+
+# Static build (for distribution)
+static: LDFLAGS += -static
+static: $(TARGET)
+
+# Check if required dependencies are available
+check-deps:
+	@echo "Checking dependencies..."
+	@pkg-config --exists $(PKG_DEPS) || (echo "Missing dependencies. Install: wayland-protocols libwayland-dev libegl1-mesa-dev libgl1-mesa-dev wayland-scanner" && exit 1)
+	@which wayland-scanner >/dev/null || (echo "wayland-scanner not found. Please install wayland-scanner." && exit 1)
+	@echo "All dependencies found."
+
+# Install
+install: $(TARGET)
+	@echo "Installing $(PROJECT_NAME)..."
+	install -Dm755 $(TARGET) $(DESTDIR)$(BINDIR_INSTALL)/$(PROJECT_NAME)
+	@if [ -f $(SYSTEMD_DIR)/$(PROJECT_NAME).service ]; then \
+		echo "Installing systemd service..."; \
+		install -Dm644 $(SYSTEMD_DIR)/$(PROJECT_NAME).service $(DESTDIR)$(SYSTEMD_INSTALL)/$(PROJECT_NAME).service; \
+	fi
+	@echo "Installation complete."
+
+# Uninstall
+uninstall:
+	@echo "Uninstalling $(PROJECT_NAME)..."
+	rm -f $(DESTDIR)$(BINDIR_INSTALL)/$(PROJECT_NAME)
+	rm -f $(DESTDIR)$(SYSTEMD_INSTALL)/$(PROJECT_NAME).service
+	@echo "Uninstall complete."
+
+# Create systemd service file
+systemd-service: $(SYSTEMD_DIR)/$(PROJECT_NAME).service
+
+
+# Clean build artifacts
+clean:
+	@echo "Cleaning build artifacts..."
+	rm -rf $(OBJDIR) $(BINDIR)
+	rm -f $(PROTOCOL_HEADERS) $(PROTOCOL_SOURCES)
+
+# Format source code (requires clang-format)
+format:
+	@echo "Formatting source code..."
+	@find $(SRCDIR) $(INCDIR) -name "*.c" -o -name "*.h" | xargs clang-format -i
+
+# Static analysis (requires cppcheck)
+analyze:
+	@echo "Running static analysis..."
+	@cppcheck --enable=all --std=c11 --language=c \
+		--include=$(INCDIR) \
+		--suppress=missingIncludeSystem \
+		--quiet \
+		$(SRCDIR)
+
+# Run tests
+# FIXME: add tests
+test: $(TARGET)
+	@echo "Running tests..."
+	@echo "Tests not implemented yet."
+
+# Help target
+help:
+	@echo "Available targets:"
+	@echo "  all             - Build the main executable (default)"
+	@echo "  debug           - Build with debug symbols and sanitizers"
+	@echo "  static          - Build statically linked executable"
+	@echo "  check-deps      - Check if all dependencies are available"
+	@echo "  install         - Install the executable and systemd service"
+	@echo "  uninstall       - Remove installed files"
+	@echo "  clean           - Remove build artifacts"
+	@echo "  distclean       - Remove all generated files"
+	@echo "  format          - Format source code (requires clang-format)"
+	@echo "  analyze         - Run static analysis (requires cppcheck)"
+	@echo "  test            - Run tests"
+	@echo "  help            - Show this help message"
+	@echo ""
+	@echo "Examples:"
+	@echo "  make                    # Build with default settings"
+	@echo "  make debug              # Build debug version"
+	@echo "  make PREFIX=/usr install # Install to /usr instead of /usr/local"
+	@echo "  make CC=clang           # Use clang instead of gcc"
+
+# Include dependency files
+-include $(DEPENDS)
+
+# Phony targets
+.PHONY: all debug static check-deps install uninstall systemd-service sample-config clean distclean format analyze test help
+
+# Print variables
+print-%:
+	@echo '$*=$($*)'

README.md

@@ -0,0 +1,211 @@
+# Chroma
+
+A simple, lightweight and efficientt wallpaper daeemon for Wayland compositors
+with multi-monitor & automatic hotplugging support. Born from my woes with
+Hyprpaper, swaybg and most ironically SWWW, which turned out to be NOT a
+solution to my Wayland wallpaper woes.
+
+## Features
+
+I did not expect to be writing something too feature-rich, but I still ended up
+with something relatively convoluted. Chroma (mostly) reliably supports:
+
+- **Multi-monitors**: Automatically detects and manages wallpapers for all
+  connected displays
+- **Hotplugging**: Dynamically handles monitor connection/disconnection events
+- **Per-output configuration**: Set different wallpapers for each monitor
+- **Multiple image formats**: Supports JPEG, PNG, BMP, TGA, PSD, GIF, HDR, PIC,
+  PPM, PGM
+- **EGL/OpenGL rendering**: Hardware-accelerated wallpaper rendering
+- **Configuration file support**: Easy setup with INI-style config files
+- **Signal handling**: Graceful shutdown and configuration reload (SIGHUP)
+
+## Usage
+
+### Requirements
+
+#### Dependencies
+
+- **Wayland**: wayland-client, wayland-egl
+- **Graphics**: EGL, OpenGL
+- **System**: glibc, libm, libdl
+
+#### Development Dependencies
+
+- GCC or Clang compiler
+- Make
+- pkg-config
+- Wayland development headers
+- EGL/OpenGL development headers
+
+### Building
+
+#### Quick Build
+
+```bash
+# Check dependencies
+make check-deps
+
+# Build the daemon
+make
+
+# Or build debug version
+make debug
+```
+
+### Installation
+
+```bash
+# Install to /usr/local (default)
+sudo make install
+
+# Install to /usr
+sudo make PREFIX=/usr install
+
+# Create systemd service file
+make systemd-service
+
+# Create sample configuration
+make sample-config
+```
+
+### Configuration
+
+#### Configuration File
+
+Chroma looks for configuration files in this order:
+
+1. `~/.config/chroma/chroma.conf`
+2. `$XDG_CONFIG_HOME/chroma/chroma.conf`
+3. `./chroma.conf` (current directory)
+
+#### Sample Configuration
+
+```ini
+# Default wallpaper for outputs without specific mapping
+default_image = ~/.config/chroma/default.jpg
+
+# Output-specific wallpapers
+# Format: output.OUTPUT_NAME = /path/to/image.jpg
+output.DP-1 = ~/Pictures/monitor1.jpg
+output.DP-2 = ~/Pictures/monitor2.png
+output.HDMI-A-1 = ~/Pictures/hdmi_wallpaper.jpg
+```
+
+### Finding Output Names
+
+Use `wlr-randr` or similar tools to find your output names:
+
+```bash
+wlr-randr
+```
+
+### Command Line Options
+
+```plaintext
+Usage: chroma [OPTIONS]
+
+Options:
+  -c, --config FILE    Configuration file path
+  -d, --daemon         Run as daemon
+  -v, --verbose        Verbose logging
+  -h, --help          Show help
+  --version           Show version information
+
+Examples:
+  chroma -c ~/.config/chroma/chroma.conf
+  chroma --daemon
+```
+
+### Running Manually
+
+```bash
+# Run in foreground
+chroma
+
+# Run as daemon
+chroma --daemon
+
+# Use custom config
+chroma -c /path/to/config.conf
+```
+
+### Systemd Service
+
+```bash
+# Enable and start the service
+systemctl --user enable chroma.service
+systemctl --user start chroma.service
+
+# Check status
+systemctl --user status chroma.service
+
+# View logs
+journalctl --user -u chroma.service -f
+
+# Reload configuration
+systemctl --user reload chroma.service
+```
+
+### Auto-start with Desktop Session
+
+```bash
+# Enable the service for auto-start
+systemctl --user enable chroma.service
+
+# The service will start automatically with your graphical session
+```
+
+### Supported Wayland Compositors
+
+Chroma works with any Wayland compositor that supports:
+
+- `wl_compositor` interface
+- `wl_output` interface
+- EGL window surface creation
+
+Tested only on Hyprland.
+
+## Development
+
+### Building Debug Version
+
+```bash
+make debug
+```
+
+### Code Formatting
+
+```bash
+make format  # requires clang-format
+```
+
+### Static Analysis
+
+```bash
+make analyze  # requires cppcheck
+```
+
+## Contributing
+
+1. Fork the repository
+2. Create a feature branch
+3. Make your changes
+4. Test thoroughly
+5. Submit a pull request
+
+### Code Style
+
+- C11 standard
+- 2-space indentation
+- No tabs
+- Function names: `chroma_function_name`
+- Constants: `CHROMA_CONSTANT_NAME`
+
+## License
+
+<!--markdownlint-disable MD059 -->
+
+This project is made available under Mozilla Public License (MPL) version 2.0.
+See [LICENSE](LICENSE) for more details on the exact conditions. An online copy
+is provided [here](https://www.mozilla.org/en-US/MPL/2.0/).

chroma.conf.sample

@@ -0,0 +1,48 @@
+# This is a sample configuration file for the Chroma wallpaper daemon.
+# Lines starting with # are comments and are ignored.
+#
+# Configuration file locations (checked in order):
+#   1. ~/.config/chroma/chroma.conf
+#   2. $XDG_CONFIG_HOME/chroma/chroma.conf
+#   3. ./chroma.conf (current directory)
+#
+# To get started:
+#   1. Copy this file to ~/.config/chroma/chroma.conf
+#   2. Modify the paths to point to your wallpaper images
+#   3. Use 'wlr-randr' or similar tools to find your output names
+#   4. Restart chroma or send SIGHUP to reload configuration
+
+# This image will be used for any output that doesn't have a specific mapping.
+# Supports: JPEG, PNG, BMP, TGA, PSD, GIF, HDR, PIC, PPM, PGM
+# Paths can be absolute or relative, ~ expansion is supported.
+#
+# Alternative examples:
+# default_image = ~/Pictures/wallpapers/default.png
+# default_image = /usr/share/wallpapers/default.jpg
+# default_image = ./wallpapers/fallback.jpg
+default_image = ~/.config/chroma/default.jpg
+
+
+# Whether to run as a background daemon
+# Usually set via command line option --daemon, but can be set here too
+daemon_mode = false
+
+# Output-specific wallpaper mappings
+# ==================================
+# Format: output.OUTPUT_NAME = /path/to/image.ext
+#
+# To find your output names, run one of these commands:
+#   - wlr-randr (for wlroots-based compositors like Sway, Hyprland)
+#   - wayland-info | grep wl_output
+#   - kanshi list-outputs
+#
+# Common output name patterns:
+#   - DP-1, DP-2, DP-3, etc. (DisplayPort)
+#   - HDMI-A-1, HDMI-A-2, etc. (HDMI)
+#   - eDP-1 (embedded DisplayPort, laptops)
+#   - DVI-D-1, DVI-I-1 (DVI)
+#   - VGA-1 (VGA, legacy)
+#
+#  Example:
+#  output.HDMI-A-1 = ~/Pictures/wallpaper.jpg
+

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1759155593,
+        "narHash": "sha256-potIJyEY7ExgfiMzr44/KBODFednyzRUAE2vs4aThHs=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "13ca7febc86978bdb67c0ae94f568b189ae84eef",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,22 @@
+{
+  description = "Wayland Wallpaper Daemon";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs?ref?nixos-unstable";
+  outputs = {nixpkgs, ...}: let
+    systems = ["x86_64-linux" "aarch64-linux"];
+    forAllSystems = f:
+      builtins.listToAttrs (map (system: {
+          name = system;
+          value = f system;
+        })
+        systems);
+
+    pkgsFor = system: nixpkgs.legacyPackages.${system};
+  in {
+    devShells = forAllSystems (system: let
+      pkgs = pkgsFor system;
+    in {
+      default = pkgs.callPackage ./shell.nix {};
+    });
+  };
+}

include/chroma.h

@@ -62,6 +62,14 @@ typedef struct {
 
   // Associated wallpaper
   chroma_image_t *image;
+
+  // OpenGL resource cache
+  GLuint texture_id;
+  GLuint shader_program;
+  GLuint vbo;
+  GLuint ebo;
+  bool gl_resources_initialized;
+  bool texture_uploaded;
 } chroma_output_t;
 
 // Config mapping structure
@@ -150,6 +158,7 @@ void chroma_egl_cleanup(chroma_state_t *state);
 int chroma_surface_create(chroma_state_t *state, chroma_output_t *output);
 void chroma_surface_destroy(chroma_output_t *output);
 int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output);
+void chroma_output_invalidate_texture(chroma_output_t *output);
 
 // Layer shell functions
 void chroma_layer_surface_configure(void *data,

shell.nix

@@ -0,0 +1,51 @@
+{pkgs ? import <nixpkgs> {}}:
+pkgs.mkShell {
+  name = "chroma";
+  buildInputs = with pkgs; [
+    gnumake
+
+    # Optional development tools
+    gdb
+    valgrind
+    strace
+
+    # Code formatting and analysis
+    clang-tools # includes clang-format
+    cppcheck
+
+    # Wayland libraries
+    wayland.dev
+    wayland-protocols
+    wayland-scanner
+    libxkbcommon
+
+    # EGL/OpenGL libraries
+    libGL
+    mesa
+
+    # System libraries
+    glibc.dev
+  ];
+
+  nativeBuildInputs = with pkgs; [
+    pkg-config
+  ];
+
+  shellHook = ''
+    echo "Available commands:"
+    echo "  make          - Build the project"
+    echo "  make debug    - Build with debug symbols"
+    echo "  make clean    - Clean build artifacts"
+    echo "  make install  - Install to ~/.local"
+    echo "  make help     - Show all available targets"
+    echo
+    echo "Run 'make check-deps' to verify all dependencies are available."
+    echo
+  '';
+
+  # Environment variables for the build system
+  env = {
+    CHROMA_VERSION = "1.0.0";
+    WAYLAND_DEBUG = 1;
+  };
+}

src/core.c

@@ -87,6 +87,14 @@ static int assign_wallpaper_to_output(chroma_state_t *state,
     return CHROMA_ERROR_IMAGE;
   }
 
+  // Check if image changed and invalidate texture cache if neceessary
+  bool image_changed = (output->image != image);
+  if (image_changed && output->image) {
+    chroma_output_invalidate_texture(output);
+    chroma_log("DEBUG", "Image changed for output %u, invalidated texture",
+               output->id);
+  }
+
   // Assign image to output
   output->image = image;
 

src/image.c

@@ -49,11 +49,12 @@ int chroma_image_load(chroma_image_t *image, const char *path) {
                (double)file_size / (1024.0 * 1024.0));
   }
 
-  // Load image data using stb_image
-  stbi_set_flip_vertically_on_load(0); // Keep images right-side up
+  // Load image data using stb_image, force RGBA format to avoid conversion
+  stbi_set_flip_vertically_on_load(0); // keep images right-side up
 
   image->data =
-      stbi_load(path, &image->width, &image->height, &image->channels, 0);
+      stbi_load(path, &image->width, &image->height, &image->channels, 4);
+  image->channels = 4; // always RGBA after forced conversion
   if (!image->data) {
     chroma_log("ERROR", "Failed to load image %s: %s", path,
                stbi_failure_reason());
@@ -68,39 +69,14 @@ int chroma_image_load(chroma_image_t *image, const char *path) {
     return CHROMA_ERROR_IMAGE;
   }
 
-  // Check supported formats
-  if (image->channels < 3 || image->channels > 4) {
-    chroma_log("ERROR",
-               "Unsupported image format: %d channels (need RGB or RGBA)",
+  // Validate we have RGBA data (should always be true with forced conversion)
+  if (image->channels != 4) {
+    chroma_log("ERROR", "Failed to load image as RGBA: got %d channels",
                image->channels);
     chroma_image_free(image);
     return CHROMA_ERROR_IMAGE;
   }
 
-  // Convert RGB to RGBA if necessary for consistent handling
-  if (image->channels == 3) {
-    int pixel_count = image->width * image->height;
-    unsigned char *rgba_data = malloc(pixel_count * 4);
-    if (!rgba_data) {
-      chroma_log("ERROR", "Failed to allocate memory for RGBA conversion");
-      chroma_image_free(image);
-      return CHROMA_ERROR_MEMORY;
-    }
-
-    // Convert RGB to RGBA
-    for (int i = 0; i < pixel_count; i++) {
-      rgba_data[i * 4 + 0] = image->data[i * 3 + 0]; // R
-      rgba_data[i * 4 + 1] = image->data[i * 3 + 1]; // G
-      rgba_data[i * 4 + 2] = image->data[i * 3 + 2]; // B
-      rgba_data[i * 4 + 3] = 255;                    // A
-    }
-
-    // Replace original data
-    stbi_image_free(image->data);
-    image->data = rgba_data;
-    image->channels = 4;
-  }
-
   image->loaded = true;
 
   chroma_log("INFO", "Loaded image: %s (%dx%d, %d channels, %.2f MB)", path,
@@ -118,13 +94,8 @@ void chroma_image_free(chroma_image_t *image) {
   }
 
   if (image->data) {
-    if (image->channels == 4 && strlen(image->path) > 0) {
-      // If we converted from RGB to RGBA, use regular free()
-      free(image->data);
-    } else {
-      // If loaded directly by stb_image, use stbi_image_free()
-      stbi_image_free(image->data);
-    }
+    // Always use stbi_image_free since we load directly with stbi_load
+    stbi_image_free(image->data);
     image->data = NULL;
   }
 

src/render.c

@@ -1,4 +1,3 @@
-#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -7,6 +6,7 @@
 #include <GLES2/gl2.h>
 
 #include "../include/chroma.h"
+#include "../include/stb_image.h"
 
 // Vertex shader for simple texture rendering
 static const char *vertex_shader_source =
@@ -31,18 +31,17 @@ static const char *fragment_shader_source =
 // Vertices for a fullscreen quad
 static const float vertices[] = {
     // Position  Texcoord
-    -1.0f, -1.0f, 0.0f, 1.0f, // Bottom left
-    1.0f,  -1.0f, 1.0f, 1.0f, // Bottom right
-    1.0f,  1.0f,  1.0f, 0.0f, // Top right
-    -1.0f, 1.0f,  0.0f, 0.0f, // Top left
+    -1.0f, -1.0f, 0.0f, 1.0f, // bottom left
+    1.0f,  -1.0f, 1.0f, 1.0f, // bottom right
+    1.0f,  1.0f,  1.0f, 0.0f, // top right
+    -1.0f, 1.0f,  0.0f, 0.0f, // top left
 };
 
 static const unsigned int indices[] = {
-    0, 1, 2, // First triangle
-    2, 3, 0  // Second triangle
+    0, 1, 2, // first triangle
+    2, 3, 0  // second triangle
 };
 
-// Shader compilation helper
 static GLuint compile_shader(GLenum type, const char *source) {
   GLuint shader = glCreateShader(type);
   if (!shader) {
@@ -66,7 +65,6 @@ static GLuint compile_shader(GLenum type, const char *source) {
   return shader;
 }
 
-// Shader program creation helper
 static GLuint create_shader_program(void) {
   GLuint vertex_shader = compile_shader(GL_VERTEX_SHADER, vertex_shader_source);
   if (!vertex_shader) {
@@ -108,6 +106,145 @@ static GLuint create_shader_program(void) {
   return program;
 }
 
+// Initialize OpenGL resources for output
+static int init_gl_resources(chroma_output_t *output) {
+  if (!output || output->gl_resources_initialized) {
+    return CHROMA_OK;
+  }
+
+  // Create shader prog
+  output->shader_program = create_shader_program();
+  if (!output->shader_program) {
+    chroma_log("ERROR", "Failed to create shader program for output %u",
+               output->id);
+    return CHROMA_ERROR_EGL;
+  }
+
+  // Create and setup VBO/EBO
+  glGenBuffers(1, &output->vbo);
+  glGenBuffers(1, &output->ebo);
+
+  glBindBuffer(GL_ARRAY_BUFFER, output->vbo);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, output->ebo);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
+               GL_STATIC_DRAW);
+
+  output->texture_id = 0; // will be created when image is assigned
+  output->gl_resources_initialized = true;
+
+  chroma_log("DEBUG", "Initialized GL resources for output %u", output->id);
+  return CHROMA_OK;
+}
+
+// Create or update texture from image data
+static int update_texture_from_image(chroma_output_t *output,
+                                     chroma_image_t *image) {
+  if (!output || !image || !image->loaded) {
+    return CHROMA_ERROR_INIT;
+  }
+
+  // If image data was already freed after previous GPU upload, we can't upload
+  // again
+  if (!image->data) {
+    chroma_log("ERROR",
+               "Cannot create texture: image data already freed for %s",
+               image->path);
+    return CHROMA_ERROR_IMAGE;
+  }
+
+  // Delete existing texture if it exists
+  if (output->texture_id != 0) {
+    glDeleteTextures(1, &output->texture_id);
+    output->texture_id = 0;
+  }
+
+  // Create new texture
+  glGenTextures(1, &output->texture_id);
+  glBindTexture(GL_TEXTURE_2D, output->texture_id);
+
+  // Set texture parameters
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+  // Upload texture data (always RGBA now)
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image->width, image->height, 0,
+               GL_RGBA, GL_UNSIGNED_BYTE, image->data);
+
+  glBindTexture(GL_TEXTURE_2D, 0);
+
+  // Mark this output as having uploaded its texture
+  output->texture_uploaded = true;
+
+  // Free system RAM copy only when ALL outputs using this image have uploaded
+  // to GPU
+  if (image->data) {
+    // Count total outputs using this image and how many have uploaded
+    int total_using = 0;
+    int uploaded_count = 0;
+
+    chroma_state_t *state = output->state;
+    for (int i = 0; i < state->output_count; i++) {
+      if (state->outputs[i].active && state->outputs[i].image == image) {
+        total_using++;
+        if (state->outputs[i].texture_uploaded) {
+          uploaded_count++;
+        }
+      }
+    }
+
+    // Only free image data when ALL outputs using it have uploaded
+    if (total_using > 0 && uploaded_count >= total_using) {
+      size_t freed_bytes =
+          (size_t)image->width * image->height * image->channels;
+      stbi_image_free(image->data);
+      image->data = NULL;
+      chroma_log("INFO",
+                 "Freed %.2f MB of image data after all %d outputs uploaded to "
+                 "GPU: %s",
+                 (double)freed_bytes / (1024.0 * 1024.0), total_using,
+                 image->path);
+    }
+  }
+
+  chroma_log("DEBUG", "Updated texture for output %u (%dx%d)", output->id,
+             image->width, image->height);
+  return CHROMA_OK;
+}
+
+// Cleanup OpenGL resources for output
+static void cleanup_gl_resources(chroma_output_t *output) {
+  if (!output || !output->gl_resources_initialized) {
+    return;
+  }
+
+  if (output->texture_id != 0) {
+    glDeleteTextures(1, &output->texture_id);
+    output->texture_id = 0;
+  }
+
+  if (output->shader_program != 0) {
+    glDeleteProgram(output->shader_program);
+    output->shader_program = 0;
+  }
+
+  if (output->vbo != 0) {
+    glDeleteBuffers(1, &output->vbo);
+    output->vbo = 0;
+  }
+
+  if (output->ebo != 0) {
+    glDeleteBuffers(1, &output->ebo);
+    output->ebo = 0;
+  }
+
+  output->gl_resources_initialized = false;
+  chroma_log("DEBUG", "Cleaned up GL resources for output %u", output->id);
+}
+
 // EGL configuration selection
 static int choose_egl_config(EGLDisplay display, EGLConfig *config) {
   EGLint attributes[] = {EGL_SURFACE_TYPE,
@@ -292,6 +429,9 @@ void chroma_surface_destroy(chroma_output_t *output) {
     return;
   }
 
+  // Clean up OpenGL resources first
+  cleanup_gl_resources(output);
+
   if (output->egl_surface != EGL_NO_SURFACE) {
     eglDestroySurface(eglGetCurrentDisplay(), output->egl_surface);
     output->egl_surface = EGL_NO_SURFACE;
@@ -315,33 +455,7 @@ void chroma_surface_destroy(chroma_output_t *output) {
   chroma_log("DEBUG", "Destroyed surface for output %u", output->id);
 }
 
-// Create texture from image data
-static GLuint create_texture_from_image(chroma_image_t *image) {
-  if (!image || !image->loaded || !image->data) {
-    return 0;
-  }
-
-  GLuint texture;
-  glGenTextures(1, &texture);
-  glBindTexture(GL_TEXTURE_2D, texture);
-
-  // Set texture parameters
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-  // Upload texture data
-  GLenum format = (image->channels == 4) ? GL_RGBA : GL_RGB;
-  glTexImage2D(GL_TEXTURE_2D, 0, format, image->width, image->height, 0, format,
-               GL_UNSIGNED_BYTE, image->data);
-
-  glBindTexture(GL_TEXTURE_2D, 0);
-
-  return texture;
-}
-
-// Render wallpaper to output
+// Render wallpaper to output using cached resources
 int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
   if (!state || !output || !output->image || !output->image->loaded) {
     return CHROMA_ERROR_INIT;
@@ -355,6 +469,17 @@ int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
     return CHROMA_ERROR_EGL;
   }
 
+  if (init_gl_resources(output) != CHROMA_OK) {
+    return CHROMA_ERROR_EGL;
+  }
+
+  if (output->texture_id == 0) {
+    if (update_texture_from_image(output, output->image) != CHROMA_OK) {
+      chroma_log("ERROR", "Failed to update texture for output %u", output->id);
+      return CHROMA_ERROR_EGL;
+    }
+  }
+
   // Set viewport
   glViewport(0, 0, output->width, output->height);
 
@@ -362,42 +487,21 @@ int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
   glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
   glClear(GL_COLOR_BUFFER_BIT);
 
-  // Create shader program (should be cached in real implementation)
-  GLuint program = create_shader_program();
-  if (!program) {
-    return CHROMA_ERROR_EGL;
-  }
-
-  // Use shader program
-  glUseProgram(program);
-
-  // Create and bind texture
-  GLuint texture = create_texture_from_image(output->image);
-  if (!texture) {
-    chroma_log("ERROR", "Failed to create texture for output %u", output->id);
-    glDeleteProgram(program);
-    return CHROMA_ERROR_EGL;
-  }
+  // Use cached shader program
+  glUseProgram(output->shader_program);
 
+  // Bind cached texture
   glActiveTexture(GL_TEXTURE0);
-  glBindTexture(GL_TEXTURE_2D, texture);
-  glUniform1i(glGetUniformLocation(program, "texture"), 0);
+  glBindTexture(GL_TEXTURE_2D, output->texture_id);
+  glUniform1i(glGetUniformLocation(output->shader_program, "texture"), 0);
 
-  // Create vertex buffer objects (should be cached in real implementation)
-  GLuint vbo, ebo;
-  glGenBuffers(1, &vbo);
-  glGenBuffers(1, &ebo);
-
-  glBindBuffer(GL_ARRAY_BUFFER, vbo);
-  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
-  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
-               GL_STATIC_DRAW);
+  // Use cached VBO/EBO
+  glBindBuffer(GL_ARRAY_BUFFER, output->vbo);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, output->ebo);
 
   // Set vertex attributes
-  GLint position_attr = glGetAttribLocation(program, "position");
-  GLint texcoord_attr = glGetAttribLocation(program, "texcoord");
+  GLint position_attr = glGetAttribLocation(output->shader_program, "position");
+  GLint texcoord_attr = glGetAttribLocation(output->shader_program, "texcoord");
 
   glEnableVertexAttribArray(position_attr);
   glVertexAttribPointer(position_attr, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float),
@@ -410,11 +514,11 @@ int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
   // Draw
   glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 
-  // Cleanup
-  glDeleteBuffers(1, &vbo);
-  glDeleteBuffers(1, &ebo);
-  glDeleteTextures(1, &texture);
-  glDeleteProgram(program);
+  // Unbind resources
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+  glBindTexture(GL_TEXTURE_2D, 0);
+  glUseProgram(0);
 
   // Swap buffers
   if (!eglSwapBuffers(state->egl_display, output->egl_surface)) {
@@ -426,6 +530,21 @@ int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
   // Commit surface
   wl_surface_commit(output->surface);
 
-  chroma_log("DEBUG", "Rendered wallpaper to output %u", output->id);
+  chroma_log("DEBUG", "Rendered wallpaper to output %u (cached resources)",
+             output->id);
   return CHROMA_OK;
 }
+
+// Invalidate texture cache for output
+void chroma_output_invalidate_texture(chroma_output_t *output) {
+  if (!output || !output->gl_resources_initialized) {
+    return;
+  }
+
+  if (output->texture_id != 0) {
+    glDeleteTextures(1, &output->texture_id);
+    output->texture_id = 0;
+    output->texture_uploaded = false; // reset upload flag
+    chroma_log("DEBUG", "Invalidated texture cache for output %u", output->id);
+  }
+}

systemd/chroma.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=Chroma Wallpaper Daemon
+After=graphical-session.target
+Wants=graphical-session.target
+PartOf=graphical-session.target
+
+[Service]
+Type=simple
+ExecStart=chroma
+ExecReload=kill -HUP $MAINPID
+Restart=on-failure
+RestartSec=1
+KillMode=mixed
+TimeoutStopSec=5
+
+# Security
+NoNewPrivileges=true
+PrivateDevices=true
+ProtectSystem=strict
+ProtectHome=read-only
+ReadWritePaths=%h/.config/chroma
+
+[Install]
+WantedBy=multi-useer.target