gallium/util: whitespace, formatting fixes in u_debug_stack.c
[mesa.git] / src / gallium / auxiliary / util / u_surface.c
index 7fd6b36753b54452d1f5abdf62e72d9b1eef7640..c150d92b967c8aa26849825a40b52edd652589a6 100644 (file)
  */
 void
 u_surface_default_template(struct pipe_surface *surf,
-                           const struct pipe_resource *texture,
-                           unsigned bind)
+                           const struct pipe_resource *texture)
 {
    memset(surf, 0, sizeof(*surf));
 
    surf->format = texture->format;
-   /* XXX should filter out all non-rt/ds bind flags ? */
-   surf->usage = bind;
 }
 
+
 /**
- * Helper to quickly create an RGBA rendering surface of a certain size.
- * \param textureOut  returns the new texture
- * \param surfaceOut  returns the new surface
- * \return TRUE for success, FALSE if failure
+ * Copy 2D rect from one place to another.
+ * Position and sizes are in pixels.
+ * src_stride may be negative to do vertical flip of pixels from source.
  */
-boolean
-util_create_rgba_texture(struct pipe_context *pipe,
-                         uint width, uint height, uint bind,
-                         struct pipe_resource **textureOut)
+void
+util_copy_rect(ubyte * dst,
+               enum pipe_format format,
+               unsigned dst_stride,
+               unsigned dst_x,
+               unsigned dst_y,
+               unsigned width,
+               unsigned height,
+               const ubyte * src,
+               int src_stride,
+               unsigned src_x,
+               unsigned src_y)
 {
-   static const enum pipe_format rgbaFormats[] = {
-      PIPE_FORMAT_B8G8R8A8_UNORM,
-      PIPE_FORMAT_A8R8G8B8_UNORM,
-      PIPE_FORMAT_A8B8G8R8_UNORM,
-      PIPE_FORMAT_NONE
-   };
-   const uint target = PIPE_TEXTURE_2D;
-   enum pipe_format format = PIPE_FORMAT_NONE;
-   struct pipe_resource templ;
-   struct pipe_surface surf_templ;
-   struct pipe_screen *screen = pipe->screen;
-   uint i;
-
-   /* Choose surface format */
-   for (i = 0; rgbaFormats[i]; i++) {
-      if (screen->is_format_supported(screen, rgbaFormats[i],
-                                      target, 0, bind)) {
-         format = rgbaFormats[i];
-         break;
+   unsigned i;
+   int src_stride_pos = src_stride < 0 ? -src_stride : src_stride;
+   int blocksize = util_format_get_blocksize(format);
+   int blockwidth = util_format_get_blockwidth(format);
+   int blockheight = util_format_get_blockheight(format);
+
+   assert(blocksize > 0);
+   assert(blockwidth > 0);
+   assert(blockheight > 0);
+
+   dst_x /= blockwidth;
+   dst_y /= blockheight;
+   width = (width + blockwidth - 1)/blockwidth;
+   height = (height + blockheight - 1)/blockheight;
+   src_x /= blockwidth;
+   src_y /= blockheight;
+
+   dst += dst_x * blocksize;
+   src += src_x * blocksize;
+   dst += dst_y * dst_stride;
+   src += src_y * src_stride_pos;
+   width *= blocksize;
+
+   if (width == dst_stride && width == src_stride)
+      memcpy(dst, src, height * width);
+   else {
+      for (i = 0; i < height; i++) {
+         memcpy(dst, src, width);
+         dst += dst_stride;
+         src += src_stride;
       }
    }
-   if (format == PIPE_FORMAT_NONE)
-      return FALSE;  /* unable to get an rgba format!?! */
-
-   /* create texture */
-   memset(&templ, 0, sizeof(templ));
-   templ.target = target;
-   templ.format = format;
-   templ.last_level = 0;
-   templ.width0 = width;
-   templ.height0 = height;
-   templ.depth0 = 1;
-   templ.array_size = 1;
-   templ.bind = bind;
-
-   *textureOut = screen->resource_create(screen, &templ);
-   if (!*textureOut)
-      return FALSE;
+}
 
-   /* create surface */
-   u_surface_default_template(&surf_templ, *textureOut, bind);
-   return TRUE;
+
+/**
+ * Copy 3D box from one place to another.
+ * Position and sizes are in pixels.
+ */
+void
+util_copy_box(ubyte * dst,
+              enum pipe_format format,
+              unsigned dst_stride, unsigned dst_slice_stride,
+              unsigned dst_x, unsigned dst_y, unsigned dst_z,
+              unsigned width, unsigned height, unsigned depth,
+              const ubyte * src,
+              int src_stride, unsigned src_slice_stride,
+              unsigned src_x, unsigned src_y, unsigned src_z)
+{
+   unsigned z;
+   dst += dst_z * dst_slice_stride;
+   src += src_z * src_slice_stride;
+   for (z = 0; z < depth; ++z) {
+      util_copy_rect(dst,
+                     format,
+                     dst_stride,
+                     dst_x, dst_y,
+                     width, height,
+                     src,
+                     src_stride,
+                     src_x, src_y);
+
+      dst += dst_slice_stride;
+      src += src_slice_stride;
+   }
+}
+
+
+void
+util_fill_rect(ubyte * dst,
+               enum pipe_format format,
+               unsigned dst_stride,
+               unsigned dst_x,
+               unsigned dst_y,
+               unsigned width,
+               unsigned height,
+               union util_color *uc)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   unsigned i, j;
+   unsigned width_size;
+   int blocksize = desc->block.bits / 8;
+   int blockwidth = desc->block.width;
+   int blockheight = desc->block.height;
+
+   assert(blocksize > 0);
+   assert(blockwidth > 0);
+   assert(blockheight > 0);
+
+   dst_x /= blockwidth;
+   dst_y /= blockheight;
+   width = (width + blockwidth - 1)/blockwidth;
+   height = (height + blockheight - 1)/blockheight;
+
+   dst += dst_x * blocksize;
+   dst += dst_y * dst_stride;
+   width_size = width * blocksize;
+
+   switch (blocksize) {
+   case 1:
+      if(dst_stride == width_size)
+         memset(dst, uc->ub, height * width_size);
+      else {
+         for (i = 0; i < height; i++) {
+            memset(dst, uc->ub, width_size);
+            dst += dst_stride;
+         }
+      }
+      break;
+   case 2:
+      for (i = 0; i < height; i++) {
+         uint16_t *row = (uint16_t *)dst;
+         for (j = 0; j < width; j++)
+            *row++ = uc->us;
+         dst += dst_stride;
+      }
+      break;
+   case 4:
+      for (i = 0; i < height; i++) {
+         uint32_t *row = (uint32_t *)dst;
+         for (j = 0; j < width; j++)
+            *row++ = uc->ui[0];
+         dst += dst_stride;
+      }
+      break;
+   default:
+      for (i = 0; i < height; i++) {
+         ubyte *row = dst;
+         for (j = 0; j < width; j++) {
+            memcpy(row, uc, blocksize);
+            row += blocksize;
+         }
+         dst += dst_stride;
+      }
+      break;
+   }
+}
+
+
+void
+util_fill_box(ubyte * dst,
+              enum pipe_format format,
+              unsigned stride,
+              unsigned layer_stride,
+              unsigned x,
+              unsigned y,
+              unsigned z,
+              unsigned width,
+              unsigned height,
+              unsigned depth,
+              union util_color *uc)
+{
+   unsigned layer;
+   dst += z * layer_stride;
+   for (layer = z; layer < depth; layer++) {
+      util_fill_rect(dst, format,
+                     stride,
+                     x, y, width, height, uc);
+      dst += layer_stride;
+   }
 }
 
 
@@ -129,11 +252,10 @@ util_resource_copy_region(struct pipe_context *pipe,
                           const struct pipe_box *src_box)
 {
    struct pipe_transfer *src_trans, *dst_trans;
-   void *dst_map;
-   const void *src_map;
+   uint8_t *dst_map;
+   const uint8_t *src_map;
    enum pipe_format src_format, dst_format;
-   unsigned w = src_box->width;
-   unsigned h = src_box->height;
+   struct pipe_box dst_box;
 
    assert(src && dst);
    if (!src || !dst)
@@ -145,51 +267,57 @@ util_resource_copy_region(struct pipe_context *pipe,
    src_format = src->format;
    dst_format = dst->format;
 
-   src_trans = pipe_get_transfer(pipe,
-                                 src,
-                                 src_level,
-                                 src_box->z,
-                                 PIPE_TRANSFER_READ,
-                                 src_box->x, src_box->y, w, h);
-
-   dst_trans = pipe_get_transfer(pipe,
-                                 dst,
-                                 dst_level,
-                                 dst_z,
-                                 PIPE_TRANSFER_WRITE,
-                                 dst_x, dst_y, w, h);
-
    assert(util_format_get_blocksize(dst_format) == util_format_get_blocksize(src_format));
    assert(util_format_get_blockwidth(dst_format) == util_format_get_blockwidth(src_format));
    assert(util_format_get_blockheight(dst_format) == util_format_get_blockheight(src_format));
 
-   src_map = pipe->transfer_map(pipe, src_trans);
-   dst_map = pipe->transfer_map(pipe, dst_trans);
-
+   src_map = pipe->transfer_map(pipe,
+                                src,
+                                src_level,
+                                PIPE_TRANSFER_READ,
+                                src_box, &src_trans);
    assert(src_map);
+   if (!src_map) {
+      goto no_src_map;
+   }
+
+   dst_box.x = dst_x;
+   dst_box.y = dst_y;
+   dst_box.z = dst_z;
+   dst_box.width  = src_box->width;
+   dst_box.height = src_box->height;
+   dst_box.depth  = src_box->depth;
+
+   dst_map = pipe->transfer_map(pipe,
+                                dst,
+                                dst_level,
+                                PIPE_TRANSFER_WRITE | PIPE_TRANSFER_DISCARD_RANGE,
+                                &dst_box, &dst_trans);
    assert(dst_map);
+   if (!dst_map) {
+      goto no_dst_map;
+   }
 
-   if (src_map && dst_map) {
-      if (dst->target == PIPE_BUFFER && src->target == PIPE_BUFFER) {
-         memcpy(dst_map, src_map, w);
-      } else {
-         util_copy_rect(dst_map,
-                        dst_format,
-                        dst_trans->stride,
-                        0, 0,
-                        w, h,
-                        src_map,
-                        src_trans->stride,
-                        0,
-                        0);
-      }
+   if (dst->target == PIPE_BUFFER && src->target == PIPE_BUFFER) {
+      assert(src_box->height == 1);
+      assert(src_box->depth == 1);
+      memcpy(dst_map, src_map, src_box->width);
+   } else {
+      util_copy_box(dst_map,
+                    dst_format,
+                    dst_trans->stride, dst_trans->layer_stride,
+                    0, 0, 0,
+                    src_box->width, src_box->height, src_box->depth,
+                    src_map,
+                    src_trans->stride, src_trans->layer_stride,
+                    0, 0, 0);
    }
 
-   pipe->transfer_unmap(pipe, src_trans);
    pipe->transfer_unmap(pipe, dst_trans);
-
-   pipe->transfer_destroy(pipe, src_trans);
-   pipe->transfer_destroy(pipe, dst_trans);
+no_dst_map:
+   pipe->transfer_unmap(pipe, src_trans);
+no_src_map:
+   ;
 }
 
 
@@ -203,6 +331,7 @@ util_resource_copy_region(struct pipe_context *pipe,
  * cpp > 4 looks like a gross hack at best...
  * Plus can't use these transfer fallbacks when clearing
  * multisampled surfaces for instance.
+ * Clears all bound layers.
  */
 void
 util_clear_render_target(struct pipe_context *pipe,
@@ -212,35 +341,71 @@ util_clear_render_target(struct pipe_context *pipe,
                          unsigned width, unsigned height)
 {
    struct pipe_transfer *dst_trans;
-   void *dst_map;
+   ubyte *dst_map;
    union util_color uc;
+   unsigned max_layer;
 
    assert(dst->texture);
    if (!dst->texture)
       return;
-   /* XXX: should handle multiple layers */
-   dst_trans = pipe_get_transfer(pipe,
-                                 dst->texture,
-                                 dst->u.tex.level,
-                                 dst->u.tex.first_layer,
-                                 PIPE_TRANSFER_WRITE,
-                                 dstx, dsty, width, height);
 
-   dst_map = pipe->transfer_map(pipe, dst_trans);
+   if (dst->texture->target == PIPE_BUFFER) {
+      /*
+       * The fill naturally works on the surface format, however
+       * the transfer uses resource format which is just bytes for buffers.
+       */
+      unsigned dx, w;
+      unsigned pixstride = util_format_get_blocksize(dst->format);
+      dx = (dst->u.buf.first_element + dstx) * pixstride;
+      w = width * pixstride;
+      max_layer = 0;
+      dst_map = pipe_transfer_map(pipe,
+                                  dst->texture,
+                                  0, 0,
+                                  PIPE_TRANSFER_WRITE,
+                                  dx, 0, w, 1,
+                                  &dst_trans);
+   }
+   else {
+      max_layer = dst->u.tex.last_layer - dst->u.tex.first_layer;
+      dst_map = pipe_transfer_map_3d(pipe,
+                                     dst->texture,
+                                     dst->u.tex.level,
+                                     PIPE_TRANSFER_WRITE,
+                                     dstx, dsty, dst->u.tex.first_layer,
+                                     width, height, max_layer + 1, &dst_trans);
+   }
 
    assert(dst_map);
 
    if (dst_map) {
+      enum pipe_format format = dst->format;
       assert(dst_trans->stride > 0);
 
-      util_pack_color(color->f, dst->texture->format, &uc);
-      util_fill_rect(dst_map, dst->texture->format,
-                     dst_trans->stride,
-                     0, 0, width, height, &uc);
-   }
+      if (util_format_is_pure_integer(format)) {
+         /*
+          * We expect int/uint clear values here, though some APIs
+          * might disagree (but in any case util_pack_color()
+          * couldn't handle it)...
+          */
+         if (util_format_is_pure_sint(format)) {
+            util_format_write_4i(format, color->i, 0, &uc, 0, 0, 0, 1, 1);
+         }
+         else {
+            assert(util_format_is_pure_uint(format));
+            util_format_write_4ui(format, color->ui, 0, &uc, 0, 0, 0, 1, 1);
+         }
+      }
+      else {
+         util_pack_color(color->f, format, &uc);
+      }
 
-   pipe->transfer_unmap(pipe, dst_trans);
-   pipe->transfer_destroy(pipe, dst_trans);
+      util_fill_box(dst_map, dst->format,
+                    dst_trans->stride, dst_trans->layer_stride,
+                    0, 0, 0, width, height, max_layer + 1, &uc);
+
+      pipe->transfer_unmap(pipe, dst_trans);
+   }
 }
 
 /**
@@ -248,6 +413,7 @@ util_clear_render_target(struct pipe_context *pipe,
  * sw fallback doesn't look terribly useful here.
  * Plus can't use these transfer fallbacks when clearing
  * multisampled surfaces for instance.
+ * Clears all bound layers.
  */
 void
 util_clear_depth_stencil(struct pipe_context *pipe,
@@ -258,126 +424,265 @@ util_clear_depth_stencil(struct pipe_context *pipe,
                          unsigned dstx, unsigned dsty,
                          unsigned width, unsigned height)
 {
+   enum pipe_format format = dst->format;
    struct pipe_transfer *dst_trans;
    ubyte *dst_map;
    boolean need_rmw = FALSE;
+   unsigned max_layer, layer;
 
    if ((clear_flags & PIPE_CLEAR_DEPTHSTENCIL) &&
        ((clear_flags & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&
-       util_format_is_depth_and_stencil(dst->format))
+       util_format_is_depth_and_stencil(format))
       need_rmw = TRUE;
 
    assert(dst->texture);
    if (!dst->texture)
       return;
-   dst_trans = pipe_get_transfer(pipe,
-                                 dst->texture,
-                                 dst->u.tex.level,
-                                 dst->u.tex.first_layer,
-                                 (need_rmw ? PIPE_TRANSFER_READ_WRITE :
-                                     PIPE_TRANSFER_WRITE),
-                                 dstx, dsty, width, height);
-
-   dst_map = pipe->transfer_map(pipe, dst_trans);
 
+   max_layer = dst->u.tex.last_layer - dst->u.tex.first_layer;
+   dst_map = pipe_transfer_map_3d(pipe,
+                                  dst->texture,
+                                  dst->u.tex.level,
+                                  (need_rmw ? PIPE_TRANSFER_READ_WRITE :
+                                              PIPE_TRANSFER_WRITE),
+                                  dstx, dsty, dst->u.tex.first_layer,
+                                  width, height, max_layer + 1, &dst_trans);
    assert(dst_map);
 
    if (dst_map) {
       unsigned dst_stride = dst_trans->stride;
-      unsigned zstencil = util_pack_z_stencil(dst->texture->format, depth, stencil);
+      uint64_t zstencil = util_pack64_z_stencil(format, depth, stencil);
+      ubyte *dst_layer = dst_map;
       unsigned i, j;
       assert(dst_trans->stride > 0);
 
-      switch (util_format_get_blocksize(dst->format)) {
-      case 1:
-         assert(dst->format == PIPE_FORMAT_S8_UINT);
-         if(dst_stride == width)
-            memset(dst_map, (ubyte) zstencil, height * width);
-         else {
-            for (i = 0; i < height; i++) {
-               memset(dst_map, (ubyte) zstencil, width);
-               dst_map += dst_stride;
-            }
-         }
-         break;
-      case 2:
-         assert(dst->format == PIPE_FORMAT_Z16_UNORM);
-         for (i = 0; i < height; i++) {
-            uint16_t *row = (uint16_t *)dst_map;
-            for (j = 0; j < width; j++)
-               *row++ = (uint16_t) zstencil;
-            dst_map += dst_stride;
+      for (layer = 0; layer <= max_layer; layer++) {
+         dst_map = dst_layer;
+
+         switch (util_format_get_blocksize(format)) {
+         case 1:
+            assert(format == PIPE_FORMAT_S8_UINT);
+            if(dst_stride == width)
+               memset(dst_map, (uint8_t) zstencil, height * width);
+            else {
+               for (i = 0; i < height; i++) {
+                  memset(dst_map, (uint8_t) zstencil, width);
+                  dst_map += dst_stride;
+               }
             }
-         break;
-      case 4:
-         if (!need_rmw) {
+            break;
+         case 2:
+            assert(format == PIPE_FORMAT_Z16_UNORM);
             for (i = 0; i < height; i++) {
-               uint32_t *row = (uint32_t *)dst_map;
+               uint16_t *row = (uint16_t *)dst_map;
                for (j = 0; j < width; j++)
-                  *row++ = zstencil;
+                  *row++ = (uint16_t) zstencil;
                dst_map += dst_stride;
+               }
+            break;
+         case 4:
+            if (!need_rmw) {
+               for (i = 0; i < height; i++) {
+                  uint32_t *row = (uint32_t *)dst_map;
+                  for (j = 0; j < width; j++)
+                     *row++ = (uint32_t) zstencil;
+                  dst_map += dst_stride;
+               }
             }
-         }
-         else {
-            uint32_t dst_mask;
-            if (dst->format == PIPE_FORMAT_Z24_UNORM_S8_UINT)
-               dst_mask = 0xffffff00;
             else {
-               assert(dst->format == PIPE_FORMAT_S8_UINT_Z24_UNORM);
-               dst_mask = 0xffffff;
+               uint32_t dst_mask;
+               if (format == PIPE_FORMAT_Z24_UNORM_S8_UINT)
+                  dst_mask = 0x00ffffff;
+               else {
+                  assert(format == PIPE_FORMAT_S8_UINT_Z24_UNORM);
+                  dst_mask = 0xffffff00;
+               }
+               if (clear_flags & PIPE_CLEAR_DEPTH)
+                  dst_mask = ~dst_mask;
+               for (i = 0; i < height; i++) {
+                  uint32_t *row = (uint32_t *)dst_map;
+                  for (j = 0; j < width; j++) {
+                     uint32_t tmp = *row & dst_mask;
+                     *row++ = tmp | ((uint32_t) zstencil & ~dst_mask);
+                  }
+                  dst_map += dst_stride;
+               }
             }
-            if (clear_flags & PIPE_CLEAR_DEPTH)
-               dst_mask = ~dst_mask;
-            for (i = 0; i < height; i++) {
-               uint32_t *row = (uint32_t *)dst_map;
-               for (j = 0; j < width; j++) {
-                  uint32_t tmp = *row & dst_mask;
-                  *row++ = tmp | (zstencil & ~dst_mask);
+            break;
+         case 8:
+            if (!need_rmw) {
+               for (i = 0; i < height; i++) {
+                  uint64_t *row = (uint64_t *)dst_map;
+                  for (j = 0; j < width; j++)
+                     *row++ = zstencil;
+                  dst_map += dst_stride;
+               }
+            }
+            else {
+               uint64_t src_mask;
+
+               if (clear_flags & PIPE_CLEAR_DEPTH)
+                  src_mask = 0x00000000ffffffffull;
+               else
+                  src_mask = 0x000000ff00000000ull;
+
+               for (i = 0; i < height; i++) {
+                  uint64_t *row = (uint64_t *)dst_map;
+                  for (j = 0; j < width; j++) {
+                     uint64_t tmp = *row & ~src_mask;
+                     *row++ = tmp | (zstencil & src_mask);
+                  }
+                  dst_map += dst_stride;
                }
-               dst_map += dst_stride;
             }
+            break;
+         default:
+            assert(0);
+            break;
          }
-         break;
-      case 8:
-      {
-         uint64_t zstencil = util_pack64_z_stencil(dst->texture->format,
-                                                   depth, stencil);
+         dst_layer += dst_trans->layer_stride;
+      }
 
-         assert(dst->format == PIPE_FORMAT_Z32_FLOAT_S8X24_UINT);
+      pipe->transfer_unmap(pipe, dst_trans);
+   }
+}
 
-         if (!need_rmw) {
-            for (i = 0; i < height; i++) {
-               uint64_t *row = (uint64_t *)dst_map;
-               for (j = 0; j < width; j++)
-                  *row++ = zstencil;
-               dst_map += dst_stride;
-            }
-         }
-         else {
-            uint64_t src_mask;
 
-            if (clear_flags & PIPE_CLEAR_DEPTH)
-               src_mask = 0x00000000ffffffffull;
-            else
-               src_mask = 0x000000ff00000000ull;
+/* Return if the box is totally inside the resource.
+ */
+static boolean
+is_box_inside_resource(const struct pipe_resource *res,
+                       const struct pipe_box *box,
+                       unsigned level)
+{
+   unsigned width = 1, height = 1, depth = 1;
+
+   switch (res->target) {
+   case PIPE_BUFFER:
+      width = res->width0;
+      height = 1;
+      depth = 1;
+      break;
+   case PIPE_TEXTURE_1D:
+      width = u_minify(res->width0, level);
+      height = 1;
+      depth = 1;
+      break;
+   case PIPE_TEXTURE_2D:
+   case PIPE_TEXTURE_RECT:
+      width = u_minify(res->width0, level);
+      height = u_minify(res->height0, level);
+      depth = 1;
+      break;
+   case PIPE_TEXTURE_3D:
+      width = u_minify(res->width0, level);
+      height = u_minify(res->height0, level);
+      depth = u_minify(res->depth0, level);
+      break;
+   case PIPE_TEXTURE_CUBE:
+      width = u_minify(res->width0, level);
+      height = u_minify(res->height0, level);
+      depth = 6;
+      break;
+   case PIPE_TEXTURE_1D_ARRAY:
+      width = u_minify(res->width0, level);
+      height = 1;
+      depth = res->array_size;
+      break;
+   case PIPE_TEXTURE_2D_ARRAY:
+      width = u_minify(res->width0, level);
+      height = u_minify(res->height0, level);
+      depth = res->array_size;
+      break;
+   case PIPE_TEXTURE_CUBE_ARRAY:
+      width = u_minify(res->width0, level);
+      height = u_minify(res->height0, level);
+      depth = res->array_size;
+      assert(res->array_size % 6 == 0);
+      break;
+   case PIPE_MAX_TEXTURE_TYPES:
+      break;
+   }
 
-            for (i = 0; i < height; i++) {
-               uint64_t *row = (uint64_t *)dst_map;
-               for (j = 0; j < width; j++) {
-                  uint64_t tmp = *row & ~src_mask;
-                  *row++ = tmp | (zstencil & src_mask);
-               }
-               dst_map += dst_stride;
-            }
-         }
-         break;
-      }
-      default:
-         assert(0);
-         break;
-      }
+   return box->x >= 0 &&
+          box->x + box->width <= (int) width &&
+          box->y >= 0 &&
+          box->y + box->height <= (int) height &&
+          box->z >= 0 &&
+          box->z + box->depth <= (int) depth;
+}
+
+static unsigned
+get_sample_count(const struct pipe_resource *res)
+{
+   return res->nr_samples ? res->nr_samples : 1;
+}
+
+/**
+ * Try to do a blit using resource_copy_region. The function calls
+ * resource_copy_region if the blit description is compatible with it.
+ *
+ * It returns TRUE if the blit was done using resource_copy_region.
+ *
+ * It returns FALSE otherwise and the caller must fall back to a more generic
+ * codepath for the blit operation. (e.g. by using u_blitter)
+ */
+boolean
+util_try_blit_via_copy_region(struct pipe_context *ctx,
+                              const struct pipe_blit_info *blit)
+{
+   unsigned mask = util_format_get_mask(blit->dst.format);
+
+   /* No format conversions. */
+   if (blit->src.resource->format != blit->src.format ||
+       blit->dst.resource->format != blit->dst.format ||
+       !util_is_format_compatible(
+          util_format_description(blit->src.resource->format),
+          util_format_description(blit->dst.resource->format))) {
+      return FALSE;
    }
 
-   pipe->transfer_unmap(pipe, dst_trans);
-   pipe->transfer_destroy(pipe, dst_trans);
+   /* No masks, no filtering, no scissor. */
+   if ((blit->mask & mask) != mask ||
+       blit->filter != PIPE_TEX_FILTER_NEAREST ||
+       blit->scissor_enable) {
+      return FALSE;
+   }
+
+   /* No flipping. */
+   if (blit->src.box.width < 0 ||
+       blit->src.box.height < 0 ||
+       blit->src.box.depth < 0) {
+      return FALSE;
+   }
+
+   /* No scaling. */
+   if (blit->src.box.width != blit->dst.box.width ||
+       blit->src.box.height != blit->dst.box.height ||
+       blit->src.box.depth != blit->dst.box.depth) {
+      return FALSE;
+   }
+
+   /* No out-of-bounds access. */
+   if (!is_box_inside_resource(blit->src.resource, &blit->src.box,
+                               blit->src.level) ||
+       !is_box_inside_resource(blit->dst.resource, &blit->dst.box,
+                               blit->dst.level)) {
+      return FALSE;
+   }
+
+   /* Sample counts must match. */
+   if (get_sample_count(blit->src.resource) !=
+       get_sample_count(blit->dst.resource)) {
+      return FALSE;
+   }
+
+   if (blit->alpha_blend)
+      return FALSE;
+
+   ctx->resource_copy_region(ctx, blit->dst.resource, blit->dst.level,
+                             blit->dst.box.x, blit->dst.box.y, blit->dst.box.z,
+                             blit->src.resource, blit->src.level,
+                             &blit->src.box);
+   return TRUE;
 }