gallium: extend resource_resolve to accommodate BlitFramebuffer

Resolve via glBlitFramebuffer allows resolving a sub-region of a
renderbuffer to a different location in any mipmap level of some
other texture, and, with a new extension, even scaling. Therefore,
location and size parameters are needed.

The mask parameter was added because resolving only depth or only
stencil of a combined buffer is possible as well.

Full information about the blit operation allows the drivers to
take the most efficient path they possibly can.

4 files changed, 43 insertions, 6 deletions

diff --git a/src/gallium/docs/source/context.rst b/src/gallium/docs/source/context.rst
index 25a3245066c..3faf801b4b1 100644
--- a/src/gallium/docs/source/context.rst
+++ b/src/gallium/docs/source/context.rst
@@ -329,8 +329,15 @@ textured quad blitter.. The source and destination may be the same resource,
 but overlapping blits are not permitted.
 
 ``resource_resolve`` resolves a multisampled resource into a non-multisampled
-one. Formats and dimensions must match. This function must be present if a driver
+one. Their formats must match. This function must be present if a driver
 supports multisampling.
+The region that is to be resolved is described by ``pipe_resolve_info``, which
+provides a source and a destination rectangle.
+The source rectangle may be vertically flipped, but otherwise the dimensions
+of the rectangles must match, unless PIPE_CAP_SCALED_RESOLVE is supported,
+in which case scaling and horizontal flipping are allowed as well.
+The result of resolving depth/stencil values may be any function of the values at
+the sample points, but returning the value of the centermost sample is preferred.
 
 The interfaces to these calls are likely to change to make it easier
 for a driver to batch multiple blits with the same source and
diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index 3f6d90d1bf4..da3ee87515f 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -49,6 +49,7 @@ struct pipe_index_buffer;
 struct pipe_query;
 struct pipe_poly_stipple;
 struct pipe_rasterizer_state;
+struct pipe_resolve_info;
 struct pipe_resource;
 struct pipe_sampler_state;
 struct pipe_sampler_view;
@@ -268,13 +269,10 @@ struct pipe_context {
 
    /**
     * Resolve a multisampled resource into a non-multisampled one.
-    * Source and destination must have the same size and same format.
+    * Source and destination must be of the same format.
     */
    void (*resource_resolve)(struct pipe_context *pipe,
-                            struct pipe_resource *dst,
-                            unsigned dst_layer,
-                            struct pipe_resource *src,
-                            unsigned src_layer);
+                            const struct pipe_resolve_info *info);
 
    /*@}*/
 
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 79b89699566..7ffdf97fdfb 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -99,6 +99,9 @@ enum pipe_error {
 #define PIPE_MASK_B  0x4
 #define PIPE_MASK_A  0x8
 #define PIPE_MASK_RGBA 0xf
+#define PIPE_MASK_Z  0x10
+#define PIPE_MASK_S  0x20
+#define PIPE_MASK_ZS 0x30
 
 
 /**
@@ -468,6 +471,7 @@ enum pipe_cap {
    PIPE_CAP_MIXED_COLORBUFFER_FORMATS = 46,
    PIPE_CAP_SEAMLESS_CUBE_MAP = 47,
    PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE = 48,
+   PIPE_CAP_SCALED_RESOLVE = 49
 };
 
 /* Shader caps not specific to any single stage */
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index d442c15c02a..840b3ee0e37 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -483,6 +483,34 @@ struct pipe_draw_info
 };
 
 
+/**
+ * Information to describe a resource_resolve call.
+ */
+struct pipe_resolve_info
+{
+   struct {
+      struct pipe_resource *res;
+      unsigned level;
+      unsigned layer;
+      int x0; /**< always left */
+      int y0; /**< always top */
+      int x1; /**< determines scale if PIPE_CAP_SCALED_RESOLVE is supported */
+      int y1; /**< determines scale if PIPE_CAP_SCALED_RESOLVE is supported */
+   } dst;
+
+   struct {
+      struct pipe_resource *res;
+      unsigned layer;
+      int x0;
+      int y0;
+      int x1; /**< may be < x0 only if PIPE_CAP_SCALED_RESOLVE is supported */
+      int y1; /**< may be < y1 even if PIPE_CAP_SCALED_RESOLVE not supported */
+   } src;
+
+   unsigned mask; /**< PIPE_MASK_RGBA, Z, S or ZS */
+};
+
+
 #ifdef __cplusplus
 }
 #endif