RHI implementation of compressed texture atlasing

Automatic atlasing (which is enabled by default for normal textures)
was added as an experimental, opt-in feature in 5.11. This commit
redoes that implementation for RHI, and enables it by default.

[ChangeLog] Enable automatic atlasing of compressed textures (can be
disabled with QSG_DISABLE_COMPRESSED_ATLAS=1)

Fixes: QTBUG-78582
Change-Id: Ia8344fffdc8dd8fb476bf6a77057c359e4816487
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

9 files changed, 41 insertions, 0 deletions

diff --git a/tests/manual/scenegraph_lancelot/data/images/compressed_tex.qml b/tests/manual/scenegraph_lancelot/data/images/compressed_tex.qml
new file mode 100644
index 0000000000..3fdb54948a
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/images/compressed_tex.qml
@@ -0,0 +1,41 @@
+import QtQuick 2.14
+
+Rectangle {
+    height: 480
+    width: 320
+    color: "green"
+
+    Grid {
+        anchors.fill: parent
+        columns: 2
+        topPadding: 40
+        padding: 64
+        spacing: 64
+        rowSpacing: 48
+
+        Image {
+            source: "../shared/o1_bc1.ktx"
+        }
+        Image {
+            source: "../shared/o1.png"
+        }
+        Image {
+            source: "../shared/o2_bc1.ktx"
+        }
+        Image {
+            source: "../shared/o2.png"
+        }
+        Image {
+            source: "../shared/t1_bc2.ktx"
+        }
+        Image {
+            source: "../shared/t1.png"
+        }
+        Image {
+            source: "../shared/t2_bc2.ktx"
+        }
+        Image {
+            source: "../shared/t2.png"
+        }
+    }
+}
diff --git a/tests/manual/scenegraph_lancelot/data/shared/o1.png b/tests/manual/scenegraph_lancelot/data/shared/o1.png
new file mode 100644
index 0000000000..a122b5ac33
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/o1.png
diff --git a/tests/manual/scenegraph_lancelot/data/shared/o1_bc1.ktx b/tests/manual/scenegraph_lancelot/data/shared/o1_bc1.ktx
new file mode 100644
index 0000000000..d61194a745
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/o1_bc1.ktx
diff --git a/tests/manual/scenegraph_lancelot/data/shared/o2.png b/tests/manual/scenegraph_lancelot/data/shared/o2.png
new file mode 100644
index 0000000000..fe88b7d03c
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/o2.png
diff --git a/tests/manual/scenegraph_lancelot/data/shared/o2_bc1.ktx b/tests/manual/scenegraph_lancelot/data/shared/o2_bc1.ktx
new file mode 100644
index 0000000000..780bb1f3fe
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/o2_bc1.ktx
diff --git a/tests/manual/scenegraph_lancelot/data/shared/t1.png b/tests/manual/scenegraph_lancelot/data/shared/t1.png
new file mode 100644
index 0000000000..35e2168c0f
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/t1.png
diff --git a/tests/manual/scenegraph_lancelot/data/shared/t1_bc2.ktx b/tests/manual/scenegraph_lancelot/data/shared/t1_bc2.ktx
new file mode 100644
index 0000000000..bc109940e5
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/t1_bc2.ktx
diff --git a/tests/manual/scenegraph_lancelot/data/shared/t2.png b/tests/manual/scenegraph_lancelot/data/shared/t2.png
new file mode 100644
index 0000000000..59fca9eb58
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/t2.png
diff --git a/tests/manual/scenegraph_lancelot/data/shared/t2_bc2.ktx b/tests/manual/scenegraph_lancelot/data/shared/t2_bc2.ktx
new file mode 100644
index 0000000000..fc9ac0841b
--- /dev/null
+++ b/tests/manual/scenegraph_lancelot/data/shared/t2_bc2.ktx