再次优化全图刷新速度

common/device.c

@@ -369,26 +369,52 @@ unsigned int *bmp_load(const char *filename, int *w, int *h)
 
 void show_bmp(unsigned int *pixels, int w, int h, int x0, int y0)
 {
-    int y, x;
+    /* Clip X */
+    int x_start = 0, x_end = w;
+    if (x0 < 0) x_start = -x0;
+    if (x0 + w > fb_w) x_end = fb_w - x0;
+    if (x_start >= x_end) return;
+    int copy_bytes = (x_end - x_start) * 4;
+
+    /* Fast path: no clipping + matching stride → single memcpy */
+    if (x_start == 0 && x_end == w && y0 >= 0 && y0 + h <= fb_h && w * 4 == fb_line)
+    {
+        memcpy(fb_map + y0 * fb_line + x0 * 4, pixels, w * h * 4);
+        return;
+    }
+
+    /* Row-by-row fallback */
+    int y;
     for (y = 0; y < h; y++)
     {
-        for (x = 0; x < w; x++)
-        {
-            int sx = x0 + x;
-            int sy = y0 + y;
-            unsigned int c = pixels[y * w + x];
-            if ((c >> 24) == 0) continue;  /* skip fully transparent */
-            if (sx >= 0 && sx < fb_w && sy >= 0 && sy < fb_h)
-            {
-                fb_put(sx, sy, c & 0x00FFFFFF);
-            }
-        }
+        int sy = y0 + y;
+        if (sy < 0 || sy >= fb_h) continue;
+        memcpy(fb_map + sy * fb_line + (x0 + x_start) * 4,
+               pixels + y * w + x_start, copy_bytes);
     }
 }
 
 void bmp_display(unsigned int *pixels, int w, int h)
 {
-    show_bmp(pixels, w, h, (fb_w - w) / 2, (fb_h - h) / 2);
+    int x0 = (fb_w - w) / 2;
+    int y0 = (fb_h - h) / 2;
+
+    /* Fast path: full-screen BMP with matching stride → single memcpy */
+    if (x0 == 0 && y0 == 0 && w * 4 == fb_line)
+    {
+        memcpy(fb_map, pixels, w * h * 4);
+        return;
+    }
+
+    /* Row-by-row fallback (stride mismatch or partial placement) */
+    int y;
+    for (y = 0; y < h; y++)
+    {
+        int sy = y0 + y;
+        if (sy < 0 || sy >= fb_h) continue;
+        memcpy(fb_map + sy * fb_line + x0 * 4,
+               pixels + y * w, w * 4);
+    }
 }
 
 unsigned int *bmp_reshape(unsigned int *src, int sw, int sh, int dw, int dh)