添加壁纸功能

src/renderer/image.c

@@ -0,0 +1,95 @@
+#include <Imlib2.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "renderer.h"
+#include "types.h"
+#include "utils.h"
+
+/**
+ * @brief 生成需要由 xcb 绘制的壁纸数据
+ * @returns 壁纸数据，使用后记得释放
+ */
+uint32_t *generate_wallpaper(const wallpaper_config_t *wallpaper_config,
+                             const monitor_t *monitors, const uint32_t index,
+                             const uint32_t screen_width,
+                             const uint32_t screen_height) {
+  if (!wallpaper_config || !monitors) return NULL;
+
+  Imlib_Image final_image = imlib_create_image(screen_width, screen_height);
+  if (!final_image) return NULL;
+
+  imlib_context_set_image(final_image);
+  imlib_image_set_has_alpha(false);
+
+  /* 填充背景色 */
+  imlib_context_set_color(0, 0, 0, 255);
+  imlib_image_fill_rectangle(0, 0, screen_width, screen_height);
+
+  const monitor_t *monitor = monitors;
+  uint32_t monitor_index = 0;
+  while (monitor) {
+    uint32_t img_index = (index + monitor_index) % wallpaper_config->count;
+
+    Imlib_Image wallpaper_img =
+      imlib_load_image(wallpaper_config->path_list[img_index]);
+    if (!wallpaper_img) {
+      monitor = monitor->next;
+      monitor_index++;
+      continue;
+    }
+
+    uint32_t dst_width = monitor->monitor_width;
+    uint32_t dst_height = monitor->monitor_height;
+
+    /* 获取图片原始尺寸 */
+    imlib_context_set_image(wallpaper_img);
+    uint32_t img_width = imlib_image_get_width();
+    uint32_t img_height = imlib_image_get_height();
+
+    /* 计算缩放比例，保持原始宽高比 */
+    float width_ratio = (float)dst_width / img_width;
+    float height_ratio = (float)dst_height / img_height;
+    float scale = MAX(width_ratio, height_ratio);
+
+    uint32_t scaled_width = img_width * scale;
+    uint32_t scaled_height = img_height * scale;
+
+    /* 图片居中显示，计算原图绘制区域 */
+    int src_x = (scaled_width - dst_width) / (2 * scale);
+    int src_y = (scaled_height - dst_height) / (2 * scale);
+    int src_width = dst_width / scale;
+    int src_height = dst_height / scale;
+
+    /* 绘制图片到最终图像上 */
+    imlib_context_set_image(final_image);
+    imlib_blend_image_onto_image(wallpaper_img, 1, src_x, src_y, src_width,
+                                 src_height, monitor->monitor_x,
+                                 monitor->monitor_y, dst_width, dst_height);
+
+    /* 释放图片资源 */
+    imlib_context_set_image(wallpaper_img);
+    imlib_free_image();
+
+    monitor = monitor->next;
+    monitor_index++;
+  }
+
+  /* 获取最终图像数据 */
+  imlib_context_set_image(final_image);
+  uint32_t *data = imlib_image_get_data_for_reading_only();
+
+  /* 复制数据到自己分配的内存中（原数据会在图像释放后无效） */
+  size_t data_size = screen_width * screen_height * sizeof(uint32_t);
+  uint32_t *result = malloc(data_size);
+  if (result) memcpy(result, data, data_size);
+
+  /* 释放图像 */
+  imlib_context_set_image(final_image);
+  imlib_free_image();
+
+  return result;
+}