diff --git a/field.c b/field.c
index 84ba68f..6dd701a 100644
--- a/field.c
+++ b/field.c
@@ -1,5 +1,6 @@
 
 #include "field.h"
+#include "picture.h"
 #include <SDL3/SDL.h>
 
 #define SWAP(a, b) ({ \
@@ -8,54 +9,67 @@
     (b) = tmp; \
 })
 
-void Field_init(Field *f, SDL_Renderer *rend, int w, int h) {
-    f->tl = Picture_new(rend, 0, 0, w, h, 0xffffffff /*0xff7fffff*/);
-    f->tr = Picture_new(rend, w, 0, w, h, 0xffffffff /*0xffff7fff*/);
-    f->bl = Picture_new(rend, 0, h, w, h, 0xffffffff /*0xffffff7f*/);
-    f->br = Picture_new(rend, w, h, w, h, 0xffffffff /*0xff7fff7f*/);
-    f->offset = (struct int2){ 0,  0 };
+void Field_init(Field *f, int w, int h) {
+    f->tl = Picture_new(0, 0, w, h, 0xffffffff /*0xff7fffff*/);
+    f->tr = Picture_new(w, 0, w, h, 0xffffffff /*0xffff7fff*/);
+    f->bl = Picture_new(0, h, w, h, 0xffffffff /*0xffffff7f*/);
+    f->br = Picture_new(w, h, w, h, 0xffffffff /*0xff7fff7f*/);
+    f->offset = (struct int2) { 0,  0 };
+    f->size = (struct int2) { w, h };
 }
 
-void Field_scroll(Field *f, SDL_Renderer *rend) {
-    int w = f->pics[0]->w;
-    int h = f->pics[0]->h;
+void Field_scroll(Field *f) {
+    int w = f->size.x;
+    int h = f->size.y;
     if (f->offset.y < f->tl->y) {
         SWAP(f->tl, f->bl);
         SWAP(f->tr, f->br);
         Picture_move(f->tl, 0, -2*h);
         Picture_move(f->tr, 0, -2*h);
-        Picture_render(f->tl, rend);
-        Picture_render(f->tr, rend);
     }
     if (f->offset.x < f->tl->x) {
         SWAP(f->tl, f->tr);
         SWAP(f->bl, f->br);
         Picture_move(f->tl, -2*w, 0);
         Picture_move(f->bl, -2*w, 0);
-        Picture_render(f->tl, rend);
-        Picture_render(f->bl, rend);
     }
     if (f->offset.y >= f->br->y) {
         SWAP(f->tl, f->bl);
         SWAP(f->tr, f->br);
         Picture_move(f->bl, 0, 2*h);
         Picture_move(f->br, 0, 2*h);
-        Picture_render(f->bl, rend);
-        Picture_render(f->br, rend);
     }
     if (f->offset.x >= f->br->x) {
         SWAP(f->tl, f->tr);
         SWAP(f->bl, f->br);
         Picture_move(f->tr, 2*w, 0);
         Picture_move(f->br, 2*w, 0);
-        Picture_render(f->tr, rend);
-        Picture_render(f->br, rend);
     }
 }
 
+void Field_resize(Field *f, int w, int h) {
+
+    w = (w + 7) / 8 * 8;
+    h = (h + 7) / 8 * 8;
+
+    Picture_delete(f->tl);
+    Picture_delete(f->tr);
+    Picture_delete(f->bl);
+    Picture_delete(f->br);
+
+    f->tl = Picture_new(0, 0, w, h, 0xffffffff /*0xff7fffff*/);
+    f->tr = Picture_new(w, 0, w, h, 0xffffffff /*0xffff7fff*/);
+    f->bl = Picture_new(0, h, w, h, 0xffffffff /*0xffffff7f*/);
+    f->br = Picture_new(w, h, w, h, 0xffffffff /*0xff7fff7f*/);
+
+    f->size = (struct int2) { w, h };
+}
+
 void Field_draw(Field *f, SDL_Renderer *rend) {
     for (int i = 0; i < 4; i++) {
         Picture *p = f->pics[i];
+        Picture_render(p, rend);
+
         SDL_FRect dst = {
             p->x - f->offset.x, p->y - f->offset.y, p->w, p->h,
         };
diff --git a/field.h b/field.h
index 6381b3f..849b505 100644
--- a/field.h
+++ b/field.h
@@ -14,10 +14,13 @@ typedef struct {
         Picture *pics[4];
     };
     struct int2 offset;
+    struct int2 size;
 } Field;
 
-void Field_init(Field *f, SDL_Renderer *rend, int w, int h);
+void Field_init(Field *f, int w, int h);
 
-void Field_scroll(Field *f, SDL_Renderer *rend);
+void Field_scroll(Field *f);
+
+void Field_resize(Field *f, int w, int h);
 
 void Field_draw(Field *f, SDL_Renderer *rend);
diff --git a/picture.c b/picture.c
index 463fcc6..8172e1d 100644
--- a/picture.c
+++ b/picture.c
@@ -2,9 +2,9 @@
 #include <stdlib.h>
 
 #include "picture.h"
+#include "SDL3/SDL_render.h"
 
-Picture *Picture_new(SDL_Renderer *rend,
-    int x, int y, int w, int h, uint32_t color) {
+Picture *Picture_new(int x, int y, int w, int h, uint32_t color) {
     
     Picture *p = calloc(1, sizeof(Picture));
 
@@ -14,6 +14,7 @@ Picture *Picture_new(SDL_Renderer *rend,
     p->h = h;
     p->color = color;
     p->s = (w * sizeof(uint32_t) + 7) / 8 * 8;
+    p->dirty = 1;
 
     p->pixels = malloc(p->s * h);
     p->surface = SDL_CreateSurfaceFrom(w, h, SDL_PIXELFORMAT_RGBA32, p->pixels, p->s);
@@ -21,13 +22,21 @@ Picture *Picture_new(SDL_Renderer *rend,
         fprintf(stderr, "Can't create surface: %s\n", SDL_GetError());
         exit(-1);
     }
-    Picture_render(p, rend);
     return p;
 }
 
+void Picture_delete(Picture *p) {
+    if (p->texture != NULL) SDL_DestroyTexture(p->texture);
+    SDL_DestroySurface(p->surface);
+    free(p->pixels);
+    free(p);
+}
+
 typedef uint32_t uint32_8 __attribute__ ((vector_size (8 * sizeof(uint32_t))));
 
 void Picture_render(Picture *p, SDL_Renderer *rend) {
+    if (!p->dirty) return;
+
     int w = p->w, h = p->h;
     uint32_8 c = {
         p->color, p->color, p->color, p->color,
@@ -51,10 +60,12 @@ void Picture_render(Picture *p, SDL_Renderer *rend) {
         exit(-1);
     }
     SDL_SetTextureBlendMode(p->texture, SDL_BLENDMODE_NONE);
+    p->dirty = 0;
 }
 
 void Picture_move(Picture *p, int x, int y) {
     p->x += x;
     p->y += y;
+    p->dirty = 1;
 }
 
diff --git a/picture.h b/picture.h
index f434625..7961ffd 100644
--- a/picture.h
+++ b/picture.h
@@ -13,11 +13,12 @@ typedef struct {
     SDL_Texture *texture;
     uint32_t *pixels;
     uint32_t color;
+    int dirty;
 } Picture;
 
 void Picture_render(Picture *p, SDL_Renderer *rend);
-Picture *Picture_new(SDL_Renderer *rend,
-    int x, int y, int w, int h, uint32_t color);
+Picture *Picture_new(int x, int y, int w, int h, uint32_t color);
+void Picture_delete(Picture *p);
 
 void Picture_render(Picture *p, SDL_Renderer *rend);
 void Picture_move(Picture *p, int x, int y);
diff --git a/xormod.c b/xormod.c
index 51bf802..f18d1b2 100644
--- a/xormod.c
+++ b/xormod.c
@@ -18,7 +18,7 @@ int main() {
         return -1;
     }
 
-    SDL_Window *window = SDL_CreateWindow("xormod", w, h, ACCEL_PLATFORM);
+    SDL_Window *window = SDL_CreateWindow("xormod", w, h, ACCEL_PLATFORM | SDL_WINDOW_RESIZABLE);
     if (window == NULL) {
         fprintf(stderr, "Can't open window: %s\n", SDL_GetError());
         return -1;
@@ -29,7 +29,7 @@ int main() {
     SDL_Renderer *rend = SDL_CreateRenderer(window, NULL);
 
     Field f;
-    Field_init(&f, rend, w, h);
+    Field_init(&f, w, h);
 
     struct float2 mouse_prev = { -1, -1 };
     Uint64 last = SDL_GetTicks();
@@ -68,11 +68,14 @@ int main() {
             mouse_prev = (struct float2) { -1, -1 };
         }
 
-        Field_scroll(&f, rend);
+        SDL_SetRenderDrawColor(rend, 0, 0, 0, 255);
+        SDL_RenderFillRect(rend, &(SDL_FRect) { 0, 0, w, h});
+
+        Field_scroll(&f);
         Field_draw(&f, rend);
 
         if (debug) {
-            char buf[52];
+            char buf[72];
             SDL_SetRenderDrawColor(rend, 0, 0, 0, 255);
             SDL_RenderFillRect(rend, &(SDL_FRect) {
                 0, 0, sizeof(buf)*font_w, 8*font_h
@@ -81,13 +84,14 @@ int main() {
             draw_text(rend, ACCEL_PLATFORM_STR, sizeof(ACCEL_PLATFORM_STR), RC(1,1), 255, 255, 255);
 
             size_t len = snprintf(buf, sizeof(buf),
-                "off.x: %d, off.y: %d, \xEBT: %" PRIu64, f.offset.x, f.offset.y, delta);
+                "off.x: %d, off.y: %d, \xEBT: %02" PRIu64, f.offset.x, f.offset.y, delta);
             draw_text(rend, buf, len, RC(2, 1), 255, 255, 255);
 
             char *q[] = {"TL", "TR", "BL", "BR"};
             for (int i = 0; i < 4; i++) {
                 Picture *p = f.pics[i];
-                len = snprintf(buf, sizeof(buf), "%s \xB3 x: %05d, y: %05d, p: %p", q[i], p->x, p->y, p);
+                len = snprintf(buf, sizeof(buf), "%s \xB3 x: %05d, y: %05d, w: %d, h: %d, p: %p",
+                               q[i], p->x, p->y, p->w, p->h, p);
                 draw_text(rend, buf, len, RC(3+i, 1), 255, 255, 255);
             }
         }
@@ -99,7 +103,11 @@ int main() {
             switch (event.type) {
                 case SDL_EVENT_QUIT: running = 0; break;
                 case SDL_EVENT_WINDOW_RESIZED: {
-                } break;
+                    w = event.window.data1;
+                    h = event.window.data2;
+                    Field_resize(&f, w, h);
+                    break;
+                }
                 case SDL_EVENT_KEY_DOWN: {
                     if (event.key.repeat) break;
                     switch (event.key.key) {
@@ -107,7 +115,7 @@ int main() {
                         case SDLK_Q: running = 0; break;
                         case SDLK_G: debug ^= 1; break;
                     }
-                } break;
+                }
             }
         }