spicec: add sw canvas diff check

Setting CHECKDIFF=1 environment variable will compare the rendering of
the selected canvas with a software canvas. This is useful for debugging
some rendering issues, however it is far from being perfect, since it's
not able to tell whether one or the other is actually faulty. It's a
strong indication though of which operations are incorrect.

Ideally, all operations should be checked, however, a few of them are
disabled by default because they fail all the time, and it looks like
pixman is not very accurate for blending/compositing (at least visually,
it seems gl has better rendering)

1 files changed, 64 insertions, 24 deletions

diff --git a/client/display_channel.cpp b/client/display_channel.cpp
index 9ba93c48..47076ad9 100644
--- a/client/display_channel.cpp
+++ b/client/display_channel.cpp
@@ -611,6 +611,7 @@ DisplayChannel::DisplayChannel(RedClient& client, uint32_t id,
 #endif
     , _interrupt_update (*this)
     , _mig_wait_primary (false)
+    , _check_diff (getenv("CHECKDIFF") != NULL)
 {
     DisplayHandler* handler = static_cast<DisplayHandler*>(get_message_handler());
 
@@ -1280,6 +1281,22 @@ void DisplayChannel::create_canvas(int surface_id, const std::vector<int>& canva
     // make sure to refresh the whole display
     SpiceRect rect = { 0, 0, width, height };
     invalidate(rect, true);
+
+    try {
+        if (!_check_diff)
+            return;
+
+        SCanvas *canvas = new SCanvas(surface_id == 0, width, height, format,
+                                      screen()->get_window(),
+                                      _pixmap_cache, _palette_cache, _glz_window,
+                                      _surfaces_cache);
+        _swsurfaces_cache[surface_id] = canvas;
+        if (surface_id == 0) {
+            LOG_INFO("display %d: check sw", get_id());
+        }
+    } catch (...) {
+        spice_warn_if_reached();
+    }
 }
 
 void DisplayChannel::handle_mode(RedPeer::InMessage* message)
@@ -1624,29 +1641,52 @@ void DisplayChannel::handle_surface_destroy(RedPeer::InMessage* message)
     }
 }
 
-#define PRE_DRAW
-#define POST_DRAW
+#define DRAW(type, can_diff) {                                          \
+    canvas->draw_##type(*type, message->size());                        \
+    if (type->base.surface_id == 0) {                                   \
+        invalidate(type->base.box, false);                              \
+    }                                                                   \
+    if ((can_diff) && _check_diff) {                                    \
+        Canvas *swcanvas = _swsurfaces_cache[type->base.surface_id];    \
+        swcanvas->draw_##type(*type, message->size());                  \
+        check_diff(swcanvas, canvas, type->base.box);                   \
+    }                                                                   \
+}
+
+#include "red_pixmap_sw.h"
+
+void check_diff(Canvas *a, Canvas *b, const SpiceRect& rect)
+{
+    QRegion region;
+    RedPixmapSw *ap = new RedPixmapSw(rect.right, rect.bottom, RedDrawable::RGB32, true, 0);
+    RedPixmapSw *bp = new RedPixmapSw(rect.right, rect.bottom, RedDrawable::RGB32, true, 0);
+
+    region_init(&region);
+    region_add(&region, &rect);
+    a->copy_pixels(region, *ap);
+    b->copy_pixels(region, *bp);
+    ap->equal(*bp, rect);
 
-#define DRAW(type) {                                \
-    PRE_DRAW;                                       \
-    canvas->draw_##type(*type, message->size());    \
-    POST_DRAW;                                      \
-    if (type->base.surface_id == 0) {               \
-        invalidate(type->base.box, false);          \
-    }                                               \
+    delete ap;
+    delete bp;
 }
 
 void DisplayChannel::handle_copy_bits(RedPeer::InMessage* message)
 {
     Canvas *canvas;
     SpiceMsgDisplayCopyBits* copy_bits = (SpiceMsgDisplayCopyBits*)message->data();
-    PRE_DRAW;
     canvas = _surfaces_cache[copy_bits->base.surface_id];
+    Canvas *swcanvas = _swsurfaces_cache[copy_bits->base.surface_id];
+
     canvas->copy_bits(*copy_bits, message->size());
-    POST_DRAW;
     if (copy_bits->base.surface_id == 0) {
         invalidate(copy_bits->base.box, false);
     }
+
+    if (_check_diff) {
+        swcanvas->copy_bits(*copy_bits, message->size());
+        check_diff(swcanvas, canvas, copy_bits->base.box);
+    }
 }
 
 void DisplayChannel::handle_draw_fill(RedPeer::InMessage* message)
@@ -1654,7 +1694,7 @@ void DisplayChannel::handle_draw_fill(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawFill* fill = (SpiceMsgDisplayDrawFill*)message->data();
     canvas = _surfaces_cache[fill->base.surface_id];
-    DRAW(fill);
+    DRAW(fill, FALSE);
 }
 
 void DisplayChannel::handle_draw_opaque(RedPeer::InMessage* message)
@@ -1662,7 +1702,7 @@ void DisplayChannel::handle_draw_opaque(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawOpaque* opaque = (SpiceMsgDisplayDrawOpaque*)message->data();
     canvas = _surfaces_cache[opaque->base.surface_id];
-    DRAW(opaque);
+    DRAW(opaque, TRUE);
 }
 
 void DisplayChannel::handle_draw_copy(RedPeer::InMessage* message)
@@ -1670,7 +1710,7 @@ void DisplayChannel::handle_draw_copy(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawCopy* copy = (SpiceMsgDisplayDrawCopy*)message->data();
     canvas = _surfaces_cache[copy->base.surface_id];
-    DRAW(copy);
+    DRAW(copy, TRUE);
 }
 
 void DisplayChannel::handle_draw_blend(RedPeer::InMessage* message)
@@ -1678,7 +1718,7 @@ void DisplayChannel::handle_draw_blend(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawBlend* blend = (SpiceMsgDisplayDrawBlend*)message->data();
     canvas = _surfaces_cache[blend->base.surface_id];
-    DRAW(blend);
+    DRAW(blend, TRUE);
 }
 
 void DisplayChannel::handle_draw_blackness(RedPeer::InMessage* message)
@@ -1686,7 +1726,7 @@ void DisplayChannel::handle_draw_blackness(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawBlackness* blackness = (SpiceMsgDisplayDrawBlackness*)message->data();
     canvas = _surfaces_cache[blackness->base.surface_id];
-    DRAW(blackness);
+    DRAW(blackness, TRUE);
 }
 
 void DisplayChannel::handle_draw_whiteness(RedPeer::InMessage* message)
@@ -1694,7 +1734,7 @@ void DisplayChannel::handle_draw_whiteness(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawWhiteness* whiteness = (SpiceMsgDisplayDrawWhiteness*)message->data();
     canvas = _surfaces_cache[whiteness->base.surface_id];
-    DRAW(whiteness);
+    DRAW(whiteness, TRUE);
 }
 
 void DisplayChannel::handle_draw_invers(RedPeer::InMessage* message)
@@ -1702,7 +1742,7 @@ void DisplayChannel::handle_draw_invers(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawInvers* invers = (SpiceMsgDisplayDrawInvers*)message->data();
     canvas = _surfaces_cache[invers->base.surface_id];
-    DRAW(invers);
+    DRAW(invers, TRUE);
 }
 
 void DisplayChannel::handle_draw_rop3(RedPeer::InMessage* message)
@@ -1710,7 +1750,7 @@ void DisplayChannel::handle_draw_rop3(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawRop3* rop3 = (SpiceMsgDisplayDrawRop3*)message->data();
     canvas = _surfaces_cache[rop3->base.surface_id];
-    DRAW(rop3);
+    DRAW(rop3, TRUE);
 }
 
 void DisplayChannel::handle_draw_stroke(RedPeer::InMessage* message)
@@ -1718,7 +1758,7 @@ void DisplayChannel::handle_draw_stroke(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawStroke* stroke = (SpiceMsgDisplayDrawStroke*)message->data();
     canvas = _surfaces_cache[stroke->base.surface_id];
-    DRAW(stroke);
+    DRAW(stroke, TRUE);
 }
 
 void DisplayChannel::handle_draw_text(RedPeer::InMessage* message)
@@ -1726,7 +1766,7 @@ void DisplayChannel::handle_draw_text(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawText* text = (SpiceMsgDisplayDrawText*)message->data();
     canvas = _surfaces_cache[text->base.surface_id];
-    DRAW(text);
+    DRAW(text, FALSE);
 }
 
 void DisplayChannel::handle_draw_transparent(RedPeer::InMessage* message)
@@ -1734,7 +1774,7 @@ void DisplayChannel::handle_draw_transparent(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawTransparent* transparent = (SpiceMsgDisplayDrawTransparent*)message->data();
     canvas = _surfaces_cache[transparent->base.surface_id];
-    DRAW(transparent);
+    DRAW(transparent, TRUE);
 }
 
 void DisplayChannel::handle_draw_alpha_blend(RedPeer::InMessage* message)
@@ -1742,7 +1782,7 @@ void DisplayChannel::handle_draw_alpha_blend(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawAlphaBlend* alpha_blend = (SpiceMsgDisplayDrawAlphaBlend*)message->data();
     canvas = _surfaces_cache[alpha_blend->base.surface_id];
-    DRAW(alpha_blend);
+    DRAW(alpha_blend, FALSE);
 }
 
 void DisplayChannel::handle_draw_composite(RedPeer::InMessage* message)
@@ -1750,7 +1790,7 @@ void DisplayChannel::handle_draw_composite(RedPeer::InMessage* message)
     Canvas *canvas;
     SpiceMsgDisplayDrawComposite* composite = (SpiceMsgDisplayDrawComposite*)message->data();
     canvas = _surfaces_cache[composite->base.surface_id];
-    DRAW(composite);
+    DRAW(composite, TRUE);
 }
 
 void DisplayChannel::streams_time()