docs: update README with 'new' features

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ic45f39e98b73a0ec2e2ec8cbdcc2f5d66a6a6964

.gitignore

@@ -8,6 +8,7 @@ src/xdg-shell.c
 src/wlr-layer-shell-unstable-v1.c
 
 # Ignore test stuff that I create to... test stuff.
-test_*
+test_memory
+test_config
 *.jpg
 *.conf

Makefile

@@ -116,7 +116,9 @@ version-header:
 	@echo "#ifndef CHROMA_VERSION_H" > $(INCDIR)/chroma_version.h
 	@echo "#define CHROMA_VERSION_H" >> $(INCDIR)/chroma_version.h
 	@echo "" >> $(INCDIR)/chroma_version.h
+	@echo "#ifndef CHROMA_VERSION" >> $(INCDIR)/chroma_version.h
 	@echo "#define CHROMA_VERSION \"$(VERSION)\"" >> $(INCDIR)/chroma_version.h
+	@echo "#endif" >> $(INCDIR)/chroma_version.h
 	@echo "" >> $(INCDIR)/chroma_version.h
 	@echo "#endif // CHROMA_VERSION_H" >> $(INCDIR)/chroma_version.h
 

README.md

@@ -1,24 +1,39 @@
 # Chroma
 
-A simple, lightweight and efficientt wallpaper daeemon for Wayland compositors
+Super-fast, lightweight and efficient wallpaper daemon for Wayland compositors
-with multi-monitor & automatic hotplugging support. Born from my woes with
+with multi-monitor & hotplugging support. Born from my woes with Hyprpaper,
-Hyprpaper, swaybg and most ironically SWWW, which turned out to be NOT a
+swaybg and most ironically _SWWW_ (now called AWWW for some awful reason), which
-solution to my Wayland wallpaper woes.
+turned out to be NOT a solution to my Wayland wallpaper woes. Smaller, faster,
+cleaner and somehow still more feature-rich...
 
 ## Features
 
-I did not expect to be writing something too feature-rich, but I still ended up
+Chroma combines simplicity with powerful performance optimizations and
-with something relatively convoluted. Chroma (mostly) reliably supports:
+comprehensive monitor management. Here's what makes Chroma stand out:
 
-- **Multi-monitors**: Automatically detects and manages wallpapers for all
+### Core Functionality
-  connected displays
+
+- **Memory-efficient**: Smart caching and resource management
+  - **Optimized rendering**: VBO dirty flagging and reduced GPU overhead
+- **Multi-monitor support**: Automatically detects and manages wallpapers for
+  all connected displays
+  - **Configurable scaling modes**: Fill, fit, stretch, and center options per
+    monitor
 - **Hotplugging**: Dynamically handles monitor connection/disconnection events
-- **Per-output configuration**: Set different wallpapers for each monitor
+- **Per-output configuration**: Set different wallpapers and settings for each
+  monitor
+  - **Global and per-output settings**: Override defaults for specific monitors
+  - **Performance tuning**: Adjustable downsampling limits and quality
+    thresholds
 - **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)
+- **Intelligent downsampling**: Automatically reduces large image resolution to
+  save memory (up to 94% memory savings for 8K images)
+- **Advanced filtering**: Nearest, linear, bilinear, and trilinear filtering
+  options
 
 ## Usage
 
@@ -198,7 +213,7 @@ make analyze  # requires cppcheck
 
 - C11 standard
 - 2-space indentation
-- No tabs
+- No tabs (except for the Makefile, obviously)
 - Function names: `chroma_function_name`
 - Constants: `CHROMA_CONSTANT_NAME`
 
@@ -209,3 +224,5 @@ make analyze  # requires cppcheck
 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/).
+
+<!--markdownlint-enable MD059 -->

chroma.conf.sample

@@ -27,15 +27,59 @@ default_image = ~/.config/chroma/default.jpg
 # Usually set via command line option --daemon, but can be set here too
 daemon_mode = false
 
+# Global scaling mode for wallpapers (used as default for all outputs)
+# Options: fill, fit, stretch, center
+#   fill    - Fill entire output, crop if necessary (default)
+#   fit     - Fit image within output, add borders if needed
+#   stretch - Stretch to fill output, may distort aspect ratio
+#   center  - Center image at original size
+scale_mode = fill
+
+# Global image filtering quality (used as default for all outputs)
+# Options: nearest, linear, bilinear, trilinear
+#   nearest   - Nearest neighbor filtering (pixelated, fast)
+#   linear    - Linear filtering (smooth, default)
+#   bilinear  - Bilinear filtering (smoother)
+#   trilinear - Trilinear filtering (smoothest)
+filter_quality = linear
+
+# Image downsampling settings for performance optimization
+# ===================================================
+# Enable automatic downsampling of large images to save memory and improve performance
+# Set to false to keep original resolution for all images (uses more memory!)
+enable_downsampling = true
+
+# Maximum expected output resolution
+# Images larger than these dimensions may be automatically downsampled
+# Adjust based on your actual monitor setup
+max_output_width = 3840   # 4K width (change to 2560 for 1440p, 1920 for 1080p)
+max_output_height = 2160  # 4K height (change to 1440 for 1440p, 1080 for 1080p)
+
+# Minimum scale factor
+# Prevents images from being scaled below this percentage of original size
+# Useful to preserve detail on very high-resolution images
+# Range: 0.1 to 1.0 (10% to 100%)
+min_scale_factor = 0.25  # Don't scale below 25% of original size
+
 # Output-specific wallpaper mappings
 # ==================================
-# Format: output.OUTPUT_NAME = /path/to/image.ext
+# Basic format: output.OUTPUT_NAME = /path/to/image.ext
+#
+# Extended format with per-output settings:
+#   output.OUTPUT_NAME = /path/to/image.ext
+#   output.OUTPUT_NAME.scale = fill|fit|stretch|center
+#   output.OUTPUT_NAME.filter = nearest|linear|bilinear|trilinear
 #
 # To find your output names, run one of these commands:
-#   - wlr-randr (for wlroots-based compositors like Sway, Hyprland)
+#
+#   Compositor Agnostic:
+#   - wlr-randr (for wlroots-based compositors)
 #   - wayland-info | grep wl_output
 #   - kanshi list-outputs
 #
+#   Compositor Specific
+#   - hyprctl monitors -j | jq .[].name (Hyprland specific)
+#
 # Common output name patterns:
 #   - DP-1, DP-2, DP-3, etc. (DisplayPort)
 #   - HDMI-A-1, HDMI-A-2, etc. (HDMI)
@@ -43,6 +87,14 @@ daemon_mode = false
 #   - DVI-D-1, DVI-I-1 (DVI)
 #   - VGA-1 (VGA, legacy)
 #
-#  Example:
+#  Examples:
 #  output.HDMI-A-1 = ~/Pictures/wallpaper.jpg
+#  output.DP-1 = ~/Pictures/monitor1.png
+#  output.DP-1.scale = fit
+#  output.DP-1.filter = bilinear
+#  output.DP-2 = ~/Pictures/monitor2.jpg
+#  output.DP-2.scale = stretch
+#  output.eDP-1 = ~/Pictures/laptop-wallpaper.jpg
+#  output.eDP-1.scale = center
+#  output.eDP-1.filter = trilinear
 

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1759155593,
+        "lastModified": 1768665130,
-        "narHash": "sha256-potIJyEY7ExgfiMzr44/KBODFednyzRUAE2vs4aThHs=",
+        "narHash": "sha256-N9eZwqdrubgKRDICaJ92Q5UMghBR1nbHnokSgZ21EJI=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "13ca7febc86978bdb67c0ae94f568b189ae84eef",
+        "rev": "c444f4a39d8efbf5e07d678ffde3e661735e1d7e",
         "type": "github"
       },
       "original": {

flake.nix

@@ -1,8 +1,11 @@
 {
-  description = "Wayland Wallpaper Daemon";
+  description = "Super-fast, lightweight and efficient wallpaper daemon for Wayland compositors";
-
   inputs.nixpkgs.url = "github:NixOS/nixpkgs?ref?nixos-unstable";
-  outputs = {nixpkgs, ...}: let
+  outputs = {
+    nixpkgs,
+    self,
+    ...
+  }: let
     systems = ["x86_64-linux" "aarch64-linux"];
     forAllSystems = f:
       builtins.listToAttrs (map (system: {
@@ -18,5 +21,12 @@
     in {
       default = pkgs.callPackage ./shell.nix {};
     });
+
+    packages = forAllSystems (system: let
+      pkgs = pkgsFor system;
+    in {
+      chroma = pkgs.callPackage ./nix/package.nix {};
+      default = self.packages.${system}.chroma;
+    });
   };
 }

include/chroma.h

@@ -99,6 +99,7 @@ typedef struct {
   GLuint ebo;
   bool gl_resources_initialized;
   bool texture_uploaded;
+  bool vbo_dirty; // track VBO needs update
 } chroma_output_t;
 
 // Config mapping structure
@@ -119,6 +120,12 @@ typedef struct {
   // Global scaling and filtering settings (used as defaults)
   chroma_scale_mode_t default_scale_mode;
   chroma_filter_quality_t default_filter_quality;
+
+  // Image downsampling settings
+  bool enable_downsampling; // enable automatic downsampling
+  int max_output_width;     // maximum expected output width
+  int max_output_height;    // maximum expected output height
+  float min_scale_factor;   // minimum scale factor (don't scale below this)
 } chroma_config_t;
 
 // Main application state
@@ -205,7 +212,8 @@ void chroma_layer_surface_closed(void *data,
 
 // Image loading
 void chroma_image_init_stb(void);
-int chroma_image_load(chroma_image_t *image, const char *path);
+int chroma_image_load(chroma_image_t *image, const char *path,
+                      const chroma_config_t *config);
 void chroma_image_free(chroma_image_t *image);
 chroma_image_t *chroma_image_find_by_path(chroma_state_t *state,
                                           const char *path);
@@ -224,7 +232,7 @@ const char *chroma_config_get_image_for_output(chroma_config_t *config,
 int chroma_config_get_mapping_for_output(
     chroma_config_t *config, const char *output_name,
     chroma_scale_mode_t *scale_mode, chroma_filter_quality_t *filter_quality);
-int chroma_config_create_sample(const char *config_file);
+
 void chroma_config_print(const chroma_config_t *config);
 
 // Main loop and events

nix/package.nix

@@ -0,0 +1,65 @@
+{
+  lib,
+  stdenv,
+  wayland,
+  wayland-protocols,
+  wayland-scanner,
+  libxkbcommon,
+  libGL,
+  mesa,
+  glibc,
+  pkg-config,
+}: let
+  fs = lib.fileset;
+  s = ../.;
+in
+  stdenv.mkDerivation {
+    pname = "chroma";
+    version = "1.0.0";
+
+    src = fs.toSource {
+      root = s;
+      fileset = fs.unions [
+        (s + /include)
+        (s + /protocols)
+        (s + /src)
+
+        (s + /Makefile)
+      ];
+    };
+
+    buildInputs = [
+      # Wayland libraries
+      wayland.dev
+      wayland-protocols
+      wayland-scanner
+      libxkbcommon
+
+      # EGL/OpenGL libraries
+      libGL
+      mesa
+
+      # System libraries
+      glibc.dev
+    ];
+
+    nativeBuildInputs = [
+      pkg-config
+    ];
+
+    makeFlags = [
+      "PREFIX=$(out)"
+      "SYSTEMD_DIR=$(out)/lib/systemd/system"
+    ];
+
+    postInstall = ''
+      install -Dm755 ${../chroma.conf.sample} $out/share/chroma.conf.sample
+    '';
+
+    meta = {
+      description = "Super-fast, lightweight and efficient wallpaper daemon for Wayland compositors";
+      license = lib.licenses.mpl20;
+      mainProgram = "chroma";
+      maintainers = with lib.maitainers; [NotAShelf];
+    };
+  }

shell.nix

@@ -25,6 +25,9 @@ pkgs.mkShell {
 
     # System libraries
     glibc.dev
+
+    # For Tests
+    (python313.withPackages (ps: with ps; [matplotlib numpy]))
   ];
 
   nativeBuildInputs = with pkgs; [
@@ -44,8 +47,5 @@ pkgs.mkShell {
   '';
 
   # Environment variables for the build system
-  env = {
+  env.WAYLAND_DEBUG = 1;
-    CHROMA_VERSION = "1.0.0";
-    WAYLAND_DEBUG = 1;
-  };
 }

src/config.c

@@ -184,6 +184,12 @@ static void init_default_config(chroma_config_t *config) {
   config->default_scale_mode = CHROMA_SCALE_FILL;
   config->default_filter_quality = CHROMA_FILTER_LINEAR;
 
+  // Set default downsampling settings
+  config->enable_downsampling = true; // enable by default, performance etc.
+  config->max_output_width = 3840;    // 4K width
+  config->max_output_height = 2160;   // 4K height
+  config->min_scale_factor = 0.25f;   // don't scale below 25%
+
   // Set default image path (can be overridden)
   const char *home = getenv("HOME");
   if (home) {
@@ -276,6 +282,34 @@ static int parse_config_line(chroma_config_t *config, char *line,
                "Filter quality configuration: key='%s', value='%s', parsed=%s",
                key, value,
                filter_quality_to_string(config->default_filter_quality));
+  } else if (strcasecmp(key, "enable_downsampling") == 0) {
+    config->enable_downsampling = parse_bool(value);
+    chroma_log("DEBUG", "Set downsampling: %s",
+               config->enable_downsampling ? "enabled" : "disabled");
+  } else if (strcasecmp(key, "max_output_width") == 0) {
+    int width = atoi(value);
+    if (width > 0 && width <= 16384) { // Reasonable limits
+      config->max_output_width = width;
+      chroma_log("DEBUG", "Set max output width: %d", width);
+    } else {
+      chroma_log("WARN", "Invalid max_output_width: %s (using 3840)", value);
+    }
+  } else if (strcasecmp(key, "max_output_height") == 0) {
+    int height = atoi(value);
+    if (height > 0 && height <= 16384) { // Reasonable limits
+      config->max_output_height = height;
+      chroma_log("DEBUG", "Set max output height: %d", height);
+    } else {
+      chroma_log("WARN", "Invalid max_output_height: %s (using 2160)", value);
+    }
+  } else if (strcasecmp(key, "min_scale_factor") == 0) {
+    float factor = atof(value);
+    if (factor > 0.0f && factor <= 1.0f) { // Valid range
+      config->min_scale_factor = factor;
+      chroma_log("DEBUG", "Set minimum scale factor: %.2f", factor);
+    } else {
+      chroma_log("WARN", "Invalid min_scale_factor: %s (using 0.25)", value);
+    }
   } else if (strncasecmp(key, "output.", 7) == 0) {
     // Output-specific mapping: e.g., output.DP-1=/path/to/image.jpg
     const char *output_name = key + 7;
@@ -515,39 +549,7 @@ int chroma_config_get_mapping_for_output(
   return CHROMA_OK;
 }
 
-// Create a sample configuration file
-int chroma_config_create_sample(const char *config_file) {
-  if (!config_file) {
-    return CHROMA_ERROR_INIT;
-  }
 
-  FILE *file = fopen(config_file, "w");
-  if (!file) {
-    chroma_log("ERROR", "Failed to create sample config file %s: %s",
-               config_file, strerror(errno));
-    return CHROMA_ERROR_CONFIG;
-  }
-
-  fprintf(file, "# Chroma Wallpaper Daemon Configuration\n");
-  fprintf(file, "# Lines starting with # are comments\n\n");
-
-  fprintf(file, "# Default wallpaper for outputs without specific mapping\n");
-  fprintf(file, "default_image = ~/.config/chroma/default.jpg\n\n");
-
-  fprintf(file, "# Output-specific wallpapers\n");
-  fprintf(file, "# Format: output.OUTPUT_NAME = /path/to/image.jpg\n");
-  fprintf(file, "# You can find output names using: wlr-randr\n");
-  fprintf(file, "\n");
-  fprintf(file, "# Examples:\n");
-  fprintf(file, "# output.DP-1 = ~/.config/chroma/monitor1.jpg\n");
-  fprintf(file, "# output.DP-2 = ~/.config/chroma/monitor2.png\n");
-  fprintf(file, "# output.HDMI-A-1 = ~/.config/chroma/hdmi.jpg\n");
-
-  fclose(file);
-
-  chroma_log("INFO", "Created sample configuration file: %s", config_file);
-  return CHROMA_OK;
-}
 
 // Print current configuration for debugging
 void chroma_config_print(const chroma_config_t *config) {
@@ -562,6 +564,13 @@ void chroma_config_print(const chroma_config_t *config) {
              scale_mode_to_string(config->default_scale_mode));
   chroma_log("INFO", "Default filter quality: %s",
              filter_quality_to_string(config->default_filter_quality));
+  chroma_log("INFO", "Downsampling: %s",
+             config->enable_downsampling ? "enabled" : "disabled");
+  if (config->enable_downsampling) {
+    chroma_log("INFO", "Max output size: %dx%d", config->max_output_width,
+               config->max_output_height);
+    chroma_log("INFO", "Min scale factor: %.2f", config->min_scale_factor);
+  }
   chroma_log("INFO", "Output mappings: %d", config->mapping_count);
 
   for (int i = 0; i < config->mapping_count; i++) {

src/core.c

@@ -96,6 +96,7 @@ static int assign_wallpaper_to_output(chroma_state_t *state,
   bool image_changed = (output->image != image);
   if (image_changed && output->image) {
     chroma_output_invalidate_texture(output);
+    output->vbo_dirty = true; // VBO needs update for new image
     chroma_log("DEBUG", "Image changed for output %u, invalidated texture",
                output->id);
   }
@@ -103,6 +104,11 @@ static int assign_wallpaper_to_output(chroma_state_t *state,
   // Assign image to output
   output->image = image;
 
+  // Mark VBO as dirty if image changed
+  if (image_changed) {
+    output->vbo_dirty = true;
+  }
+
   // Store old configuration values for comparison
   chroma_scale_mode_t old_scale_mode = output->scale_mode;
   chroma_filter_quality_t old_filter_quality = output->filter_quality;
@@ -120,6 +126,7 @@ static int assign_wallpaper_to_output(chroma_state_t *state,
     if (had_config && (old_scale_mode != output->scale_mode ||
                        old_filter_quality != output->filter_quality)) {
       chroma_output_invalidate_texture(output);
+      output->vbo_dirty = true; // VBO needs update for new scale mode
       chroma_log("DEBUG",
                  "Configuration changed for output %u, invalidated texture",
                  output->id);
@@ -273,14 +280,14 @@ int chroma_run(chroma_state_t *state) {
       break;
     }
 
-    // Use select() to wait for events with timeout
+    // Use `select()` to wait for events with longer timeout to reduce CPU usage
     fd_set readfds;
     struct timeval timeout;
 
     FD_ZERO(&readfds);
     FD_SET(fd, &readfds);
 
-    timeout.tv_sec = 1; // 1s timeout
+    timeout.tv_sec = 10;
     timeout.tv_usec = 0;
 
     int select_result = select(fd + 1, &readfds, NULL, NULL, &timeout);

src/image.c

@@ -24,8 +24,76 @@ static long get_file_size(const char *path) {
   return st.st_size;
 }
 
-// Load image from file
+// Calculate optimal image size based on output dimensions
-int chroma_image_load(chroma_image_t *image, const char *path) {
+static void calculate_optimal_size(int original_width, int original_height,
+                                   int max_output_width, int max_output_height,
+                                   int *optimal_width, int *optimal_height) {
+  // If image is smaller than outputs, keep original size
+  if (original_width <= max_output_width &&
+      original_height <= max_output_height) {
+    *optimal_width = original_width;
+    *optimal_height = original_height;
+    return;
+  }
+
+  // Calculate scale factor to fit within max output dimensions
+  float scale_x = (float)max_output_width / original_width;
+  float scale_y = (float)max_output_height / original_height;
+  float scale = (scale_x < scale_y) ? scale_x : scale_y;
+
+  // Apply scale factor with minimum size to avoid too small images
+  scale = (scale > 1.0f) ? 1.0f : scale;
+  scale = (scale < 0.25f) ? 0.25f : scale; // XXX: don't scale below 25%
+
+  *optimal_width = (int)(original_width * scale);
+  *optimal_height = (int)(original_height * scale);
+
+  // Ensure even dimensions for better GPU alignment
+  *optimal_width = (*optimal_width / 2) * 2;
+  *optimal_height = (*optimal_height / 2) * 2;
+}
+
+// FIXME: this is a very simple way of implementing box filter downsampling for
+// memory efficiency Could be better, but this is good enough *for the time
+// being*. Must be revisited in the future to see how it stands as the program
+// evolves.
+static int downsample_image(unsigned char *src_data, int src_width,
+                            int src_height, unsigned char *dst_data,
+                            int dst_width, int dst_height) {
+  if (!src_data || !dst_data) {
+    return -1;
+  }
+
+  float x_ratio = (float)src_width / dst_width;
+  float y_ratio = (float)src_height / dst_height;
+
+  for (int y = 0; y < dst_height; y++) {
+    for (int x = 0; x < dst_width; x++) {
+      // Calculate corresponding source pixel
+      int src_x = (int)(x * x_ratio);
+      int src_y = (int)(y * y_ratio);
+
+      // Ensure we're within bounds
+      src_x = (src_x >= src_width) ? src_width - 1 : src_x;
+      src_y = (src_y >= src_height) ? src_height - 1 : src_y;
+
+      // Copy pixel (RGBA)
+      int src_idx = (src_y * src_width + src_x) * 4;
+      int dst_idx = (y * dst_width + x) * 4;
+
+      dst_data[dst_idx + 0] = src_data[src_idx + 0]; // R
+      dst_data[dst_idx + 1] = src_data[src_idx + 1]; // G
+      dst_data[dst_idx + 2] = src_data[src_idx + 2]; // B
+      dst_data[dst_idx + 3] = src_data[src_idx + 3]; // A
+    }
+  }
+
+  return 0;
+}
+
+// Load image from file with configurable downsampling
+int chroma_image_load(chroma_image_t *image, const char *path,
+                      const chroma_config_t *config) {
   if (!image || !path) {
     chroma_log("ERROR", "Invalid parameters for image loading");
     return CHROMA_ERROR_INIT;
@@ -77,15 +145,87 @@ int chroma_image_load(chroma_image_t *image, const char *path) {
     return CHROMA_ERROR_IMAGE;
   }
 
+  // Store original dimensions before potential downsampling
+  int original_width = image->width;
+  int original_height = image->height;
+
+  // Apply intelligent downsampling if enabled
+  bool should_downsample = false;
+  int optimal_width = original_width;
+  int optimal_height = original_height;
+
+  if (config && config->enable_downsampling) {
+    calculate_optimal_size(original_width, original_height,
+                           config->max_output_width, config->max_output_height,
+                           &optimal_width, &optimal_height);
+
+    // Apply minimum scale factor constraint
+    float scale_x = (float)optimal_width / original_width;
+    float scale_y = (float)optimal_height / original_height;
+    float scale = (scale_x < scale_y) ? scale_x : scale_y;
+
+    if (scale < config->min_scale_factor) {
+      scale = config->min_scale_factor;
+      optimal_width = (int)(original_width * scale);
+      optimal_height = (int)(original_height * scale);
+
+      // Ensure even dimensions
+      optimal_width = (optimal_width / 2) * 2;
+      optimal_height = (optimal_height / 2) * 2;
+    }
+
+    should_downsample =
+        (optimal_width < original_width || optimal_height < original_height);
+  }
+
+  // Downsamp if needed and enabled
+  if (should_downsample) {
+    chroma_log("INFO",
+               "Downsampling image from %dx%d to %dx%d (%.1f%% of original)",
+               original_width, original_height, optimal_width, optimal_height,
+               (float)(optimal_width * optimal_height) /
+                   (original_width * original_height) * 100.0f);
+
+    size_t optimal_size = (size_t)optimal_width * optimal_height * 4;
+    unsigned char *downsampled_data = malloc(optimal_size);
+    if (!downsampled_data) {
+      chroma_log("ERROR", "Failed to allocate memory for downsampled image");
+      chroma_image_free(image);
+      return CHROMA_ERROR_MEMORY;
+    }
+
+    if (downsample_image(image->data, original_width, original_height,
+                         downsampled_data, optimal_width,
+                         optimal_height) != 0) {
+      chroma_log("ERROR", "Failed to downsample image");
+      free(downsampled_data);
+      chroma_image_free(image);
+      return CHROMA_ERROR_IMAGE;
+    }
+
+    stbi_image_free(image->data);
+    image->data = downsampled_data;
+    image->width = optimal_width;
+    image->height = optimal_height;
+
+    chroma_log("DEBUG", "Successfully downsampled image to %dx%d",
+               optimal_width, optimal_height);
+  } else if (config && !config->enable_downsampling) {
+    chroma_log("DEBUG",
+               "Downsampling disabled, keeping original resolution %dx%d",
+               original_width, original_height);
+  }
+
   image->loaded = true;
 
   // Calculate and log memory allocation
   size_t image_size = (size_t)image->width * image->height * image->channels;
   chroma_log_resource_allocation("image_data", image_size, path);
 
-  chroma_log("INFO", "Loaded image: %s (%dx%d, %d channels, %.2f MB)", path,
+  chroma_log("INFO", "Loaded image: %s (%dx%d, %d channels, %.2f MB)%s", path,
              image->width, image->height, image->channels,
-             (double)image_size / (1024.0 * 1024.0));
+             (double)image_size / (1024.0 * 1024.0),
+             should_downsample ? " (downsampled)" : "");
 
   return CHROMA_OK;
 }
@@ -159,8 +299,8 @@ chroma_image_t *chroma_image_get_or_load(chroma_state_t *state,
     state->image_count++;
   }
 
-  // Load the image
+  // Load the image with configuration
-  if (chroma_image_load(image, path) != CHROMA_OK) {
+  if (chroma_image_load(image, path, &state->config) != CHROMA_OK) {
     // If this was a new slot, decrement count
     if (!existing) {
       state->image_count--;
@@ -241,7 +381,7 @@ void chroma_image_init_stb(void) {
   // Set stb_image options
   stbi_set_flip_vertically_on_load(0);
 
-  // These could be made configurable
+  // FIXME: these could be made configurable
   stbi_ldr_to_hdr_gamma(2.2f);
   stbi_ldr_to_hdr_scale(1.0f);
 

src/render.c

@@ -10,27 +10,33 @@
 
 // Convert filter quality enum to OpenGL parameters
 static void get_gl_filter_params(chroma_filter_quality_t quality,
-                                 GLint *min_filter, GLint *mag_filter) {
+                                 GLint *min_filter, GLint *mag_filter,
+                                 bool *needs_mipmaps) {
   switch (quality) {
   case CHROMA_FILTER_NEAREST:
     *min_filter = GL_NEAREST;
     *mag_filter = GL_NEAREST;
+    *needs_mipmaps = false;
     break;
   case CHROMA_FILTER_LINEAR:
     *min_filter = GL_LINEAR;
     *mag_filter = GL_LINEAR;
+    *needs_mipmaps = false;
     break;
   case CHROMA_FILTER_BILINEAR:
-    *min_filter = GL_LINEAR_MIPMAP_LINEAR;
+    *min_filter = GL_LINEAR;
     *mag_filter = GL_LINEAR;
+    *needs_mipmaps = false;
     break;
   case CHROMA_FILTER_TRILINEAR:
     *min_filter = GL_LINEAR_MIPMAP_LINEAR;
     *mag_filter = GL_LINEAR;
+    *needs_mipmaps = true;
     break;
   default:
     *min_filter = GL_LINEAR;
     *mag_filter = GL_LINEAR;
+    *needs_mipmaps = false;
     break;
   }
 }
@@ -271,7 +277,8 @@ static int init_gl_resources(chroma_output_t *output) {
   glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
                GL_STATIC_DRAW);
 
-  output->texture_id = 0; // will be created when image is assigned
+  output->texture_id = 0;   // will be created when image is assigned
+  output->vbo_dirty = true; // VBO needs initial update
   output->gl_resources_initialized = true;
 
   chroma_log("DEBUG", "Initialized GL resources for output %u", output->id);
@@ -324,7 +331,9 @@ static int update_texture_from_image(chroma_output_t *output,
 
   // Use configured filter quality
   GLint min_filter, mag_filter;
-  get_gl_filter_params(filter_quality, &min_filter, &mag_filter);
+  bool needs_mipmaps;
+  get_gl_filter_params(filter_quality, &min_filter, &mag_filter,
+                       &needs_mipmaps);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filter);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter);
 
@@ -332,6 +341,12 @@ static int update_texture_from_image(chroma_output_t *output,
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image->width, image->height, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, image->data);
 
+  // Generate mipmaps for trilinear filtering if they're needed
+  if (needs_mipmaps) {
+    glGenerateMipmap(GL_TEXTURE_2D);
+    chroma_log("DEBUG", "Generated mipmaps for trilinear filtering");
+  }
+
   glBindTexture(GL_TEXTURE_2D, 0);
 
   // Mark this output as having uploaded its texture
@@ -670,26 +685,36 @@ int chroma_render_wallpaper(chroma_state_t *state, chroma_output_t *output) {
   glBindTexture(GL_TEXTURE_2D, output->texture_id);
   glUniform1i(glGetUniformLocation(output->shader_program, "texture"), 0);
 
-  // Calculate texture coordinates based on scaling mode
+  // Update VBO only if needed. E.g, image changed, scale mode changed, or first
-  float tex_coords[8];
+  // render
-  calculate_texture_coords(output->scale_mode, output->image->width,
+  if (output->vbo_dirty) {
-                           output->image->height, output->width, output->height,
+    // Calculate texture coordinates based on scaling mode
-                           tex_coords);
+    float tex_coords[8];
+    calculate_texture_coords(output->scale_mode, output->image->width,
+                             output->image->height, output->width,
+                             output->height, tex_coords);
 
-  // Create dynamic vertex data with calculated texture coordinates
+    // Create dynamic vertex data with calculated texture coordinates
-  float dynamic_vertices[] = {
+    float dynamic_vertices[] = {
-      // Position  Texcoord
+        // Position  Texcoord
-      -1.0f, -1.0f, tex_coords[0], tex_coords[1], // bottom-left
+        -1.0f, -1.0f, tex_coords[0], tex_coords[1], // bottom-left
-      1.0f,  -1.0f, tex_coords[2], tex_coords[3], // bottom-right
+        1.0f,  -1.0f, tex_coords[2], tex_coords[3], // bottom-right
-      1.0f,  1.0f,  tex_coords[4], tex_coords[5], // top-right
+        1.0f,  1.0f,  tex_coords[4], tex_coords[5], // top-right
-      -1.0f, 1.0f,  tex_coords[6], tex_coords[7]  // top-left
+        -1.0f, 1.0f,  tex_coords[6], tex_coords[7]  // top-left
-  };
+    };
 
-  // Update VBO with dynamic texture coordinates
+    // Update VBO with dynamic texture coordinates
-  glBindBuffer(GL_ARRAY_BUFFER, output->vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, output->vbo);
-  glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(dynamic_vertices),
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(dynamic_vertices),
-                  dynamic_vertices);
+                    dynamic_vertices);
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, output->ebo);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, output->ebo);
+
+    output->vbo_dirty = false; // mark VBO as up to date
+  } else {
+    // Just bind the existing buffers
+    glBindBuffer(GL_ARRAY_BUFFER, output->vbo);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, output->ebo);
+  }
 
   // Set vertex attributes
   GLint position_attr = glGetAttribLocation(output->shader_program, "position");
@@ -739,4 +764,7 @@ void chroma_output_invalidate_texture(chroma_output_t *output) {
     output->texture_uploaded = false; // reset upload flag
     chroma_log("DEBUG", "Invalidated texture cache for output %u", output->id);
   }
+
+  // Mark VBO as dirty since texture coordinates may need recalculation
+  output->vbo_dirty = true;
 }