From be13d3c844a6623563ae4e74dbb3409baf16fc9c Mon Sep 17 00:00:00 2001

From: Pekka Paalanen <pekka.paalanen@collabora.com>

Date: Mon, 3 Dec 2018 14:34:41 +0200

Subject: [PATCH 07/12] cogl: Expose cogl_blit_framebuffer

The function will be used in copying from a primary GPU framebuffer to a

secondary GPU framebuffer using the primary GPU specifically when the

secondary GPU is not render-capable.

To allow falling back in case glBlitFramebuffer cannot be used, add boolean

return value, and GError argument for debugging purposes.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/615

(cherry picked from commit 6061abbf90cd1d62e262ebf3636470d2219e04a7)

---

 cogl/cogl/cogl-blit.c                | 11 ++---

 cogl/cogl/cogl-framebuffer-private.h | 55 -----------------------

 cogl/cogl/cogl-framebuffer.c         | 40 +++++++++++------

 cogl/cogl/cogl-framebuffer.h         | 66 +++++++++++++++++++++++++++-

 4 files changed, 98 insertions(+), 74 deletions(-)

diff --git a/cogl/cogl/cogl-blit.c b/cogl/cogl/cogl-blit.c

index c561b2e45..ae5a8a345 100644

--- a/cogl/cogl/cogl-blit.c

+++ b/cogl/cogl/cogl-blit.c

@@ -207,11 +207,12 @@ _cogl_blit_framebuffer_blit (CoglBlitData *data,

                              int width,

                              int height)

 {

-  _cogl_blit_framebuffer (data->src_fb,

-                          data->dest_fb,

-                          src_x, src_y,

-                          dst_x, dst_y,

-                          width, height);

+  cogl_blit_framebuffer (data->src_fb,

+                         data->dest_fb,

+                         src_x, src_y,

+                         dst_x, dst_y,

+                         width, height,

+                         NULL);

 }

 static void

diff --git a/cogl/cogl/cogl-framebuffer-private.h b/cogl/cogl/cogl-framebuffer-private.h

index cb1f87354..7d71fb1dc 100644

--- a/cogl/cogl/cogl-framebuffer-private.h

+++ b/cogl/cogl/cogl-framebuffer-private.h

@@ -367,61 +367,6 @@ void

 _cogl_push_framebuffers (CoglFramebuffer *draw_buffer,

                          CoglFramebuffer *read_buffer);

-/*

- * _cogl_blit_framebuffer:

- * @src: The source #CoglFramebuffer

- * @dest: The destination #CoglFramebuffer

- * @src_x: Source x position

- * @src_y: Source y position

- * @dst_x: Destination x position

- * @dst_y: Destination y position

- * @width: Width of region to copy

- * @height: Height of region to copy

- *

- * This blits a region of the color buffer of the source buffer

- * to the destination buffer. This function should only be

- * called if the COGL_PRIVATE_FEATURE_BLIT_FRAMEBUFFER feature is

- * advertised.

- *

- * The source and destination rectangles are defined in offscreen

- * framebuffer orientation. When copying between an offscreen and

- * onscreen framebuffers, the image is y-flipped accordingly.

- *

- * The two buffers must have the same value types (e.g. floating-point,

- * unsigned int, signed int, or fixed-point), but color formats do not

- * need to match. This limitation comes from OpenGL ES 3.0 definition

- * of glBlitFramebuffer.

- *

- * Note that this function differs a lot from the glBlitFramebuffer

- * function provided by the GL_EXT_framebuffer_blit extension. Notably

- * it doesn't support having different sizes for the source and

- * destination rectangle. This doesn't seem

- * like a particularly useful feature. If the application wanted to

- * scale the results it may make more sense to draw a primitive

- * instead.

- *

- * The GL function is documented to be affected by the scissor. This

- * function therefore ensure that an empty clip stack is flushed

- * before performing the blit which means the scissor is effectively

- * ignored.

- *

- * The function also doesn't support specifying the buffers to copy

- * and instead only the color buffer is copied. When copying the depth

- * or stencil buffers the extension on GLES2.0 only supports copying

- * the full buffer which would be awkward to document with this

- * API. If we wanted to support that feature it may be better to have

- * a separate function to copy the entire buffer for a given mask.

- */

-void

-_cogl_blit_framebuffer (CoglFramebuffer *src,

-                        CoglFramebuffer *dest,

-                        int src_x,

-                        int src_y,

-                        int dst_x,

-                        int dst_y,

-                        int width,

-                        int height);

-

 void

 _cogl_framebuffer_push_projection (CoglFramebuffer *framebuffer);

diff --git a/cogl/cogl/cogl-framebuffer.c b/cogl/cogl/cogl-framebuffer.c

index 5cc4eada4..6d35c6b13 100644

--- a/cogl/cogl/cogl-framebuffer.c

+++ b/cogl/cogl/cogl-framebuffer.c

@@ -1449,26 +1449,38 @@ cogl_framebuffer_read_pixels (CoglFramebuffer *framebuffer,

   return ret;

 }

-void

-_cogl_blit_framebuffer (CoglFramebuffer *src,

-                        CoglFramebuffer *dest,

-                        int src_x,

-                        int src_y,

-                        int dst_x,

-                        int dst_y,

-                        int width,

-                        int height)

+gboolean

+cogl_blit_framebuffer (CoglFramebuffer *src,

+                       CoglFramebuffer *dest,

+                       int src_x,

+                       int src_y,

+                       int dst_x,

+                       int dst_y,

+                       int width,

+                       int height,

+                       GError **error)

 {

   CoglContext *ctx = src->context;

   int src_x1, src_y1, src_x2, src_y2;

   int dst_x1, dst_y1, dst_x2, dst_y2;

-  _COGL_RETURN_IF_FAIL (_cogl_has_private_feature

-                        (ctx, COGL_PRIVATE_FEATURE_BLIT_FRAMEBUFFER));

+  if (!_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_BLIT_FRAMEBUFFER))

+    {

+      g_set_error_literal (error, COGL_SYSTEM_ERROR,

+                           COGL_SYSTEM_ERROR_UNSUPPORTED,

+                           "Cogl BLIT_FRAMEBUFFER is not supported by the system.");

+      return FALSE;

+    }

   /* The buffers must use the same premult convention */

-  _COGL_RETURN_IF_FAIL ((src->internal_format & COGL_PREMULT_BIT) ==

-                        (dest->internal_format & COGL_PREMULT_BIT));

+  if ((src->internal_format & COGL_PREMULT_BIT) !=

+      (dest->internal_format & COGL_PREMULT_BIT))

+    {

+      g_set_error_literal (error, COGL_SYSTEM_ERROR,

+                           COGL_SYSTEM_ERROR_UNSUPPORTED,

+                           "cogl_blit_framebuffer premult mismatch.");

+      return FALSE;

+    }

   /* Make sure the current framebuffers are bound. We explicitly avoid

      flushing the clip state so we can bind our own empty state */

@@ -1526,6 +1538,8 @@ _cogl_blit_framebuffer (CoglFramebuffer *src,

                           dst_x1, dst_y1, dst_x2, dst_y2,

                           GL_COLOR_BUFFER_BIT,

                           GL_NEAREST);

+

+  return TRUE;

 }

 void

diff --git a/cogl/cogl/cogl-framebuffer.h b/cogl/cogl/cogl-framebuffer.h

index 48a77e1ed..230a78627 100644

--- a/cogl/cogl/cogl-framebuffer.h

+++ b/cogl/cogl/cogl-framebuffer.h

@@ -3,7 +3,8 @@

  *

  * A Low Level GPU Graphics and Utilities API

  *

- * Copyright (C) 2011 Intel Corporation.

+ * Copyright (C) 2007,2008,2009,2011 Intel Corporation.

+ * Copyright (C) 2019 DisplayLink (UK) Ltd.

  *

  * Permission is hereby granted, free of charge, to any person

  * obtaining a copy of this software and associated documentation

@@ -1846,6 +1847,69 @@ typedef enum /*< prefix=COGL_FRAMEBUFFER_ERROR >*/

 gboolean

 cogl_is_framebuffer (void *object);

+/**

+ * cogl_blit_framebuffer:

+ * @src: The source #CoglFramebuffer

+ * @dest: The destination #CoglFramebuffer

+ * @src_x: Source x position

+ * @src_y: Source y position

+ * @dst_x: Destination x position

+ * @dst_y: Destination y position

+ * @width: Width of region to copy

+ * @height: Height of region to copy

+ * @error: optional error object

+ *

+ * @return FALSE for an immediately detected error, TRUE otherwise.

+ *

+ * This blits a region of the color buffer of the source buffer

+ * to the destination buffer. This function should only be

+ * called if the COGL_PRIVATE_FEATURE_BLIT_FRAMEBUFFER feature is

+ * advertised.

+ *

+ * The source and destination rectangles are defined in offscreen

+ * framebuffer orientation. When copying between an offscreen and

+ * onscreen framebuffers, the image is y-flipped accordingly.

+ *

+ * The two buffers must have the same value types (e.g. floating-point,

+ * unsigned int, signed int, or fixed-point), but color formats do not

+ * need to match. This limitation comes from OpenGL ES 3.0 definition

+ * of glBlitFramebuffer.

+ *

+ * Note that this function differs a lot from the glBlitFramebuffer

+ * function provided by the GL_EXT_framebuffer_blit extension. Notably

+ * it doesn't support having different sizes for the source and

+ * destination rectangle. This doesn't seem

+ * like a particularly useful feature. If the application wanted to

+ * scale the results it may make more sense to draw a primitive

+ * instead.

+ *

+ * The GL function is documented to be affected by the scissor. This

+ * function therefore ensure that an empty clip stack is flushed

+ * before performing the blit which means the scissor is effectively

+ * ignored.

+ *

+ * The function also doesn't support specifying the buffers to copy

+ * and instead only the color buffer is copied. When copying the depth

+ * or stencil buffers the extension on GLES2.0 only supports copying

+ * the full buffer which would be awkward to document with this

+ * API. If we wanted to support that feature it may be better to have

+ * a separate function to copy the entire buffer for a given mask.

+ *

+ * The @c error argument is optional, it can be NULL. If it is not NULL

+ * and this function returns FALSE, an error object with a code from

+ * COGL_SYSTEM_ERROR will be created.

+ */

+gboolean

+cogl_blit_framebuffer (CoglFramebuffer *src,

+                       CoglFramebuffer *dest,

+                       int src_x,

+                       int src_y,

+                       int dst_x,

+                       int dst_y,

+                       int width,

+                       int height,

+                       GError **error);

+

 G_END_DECLS

 #endif /* __COGL_FRAMEBUFFER_H */

-- 

2.21.0