rhi: Add render-to-cubemap manual test

What's more, demonstrate two types of rendering to a cubemap:
one by one to each face, and by attaching all faces as color
attachments in one go.

Both are used by Qt Quick 3D in connection with shadows, so this
proves that the same is possible to implement with QRhi.

Task-number: QTBUG-81261
Change-Id: I5c7077224d7cae0dd6ea02ac30a9e6f9f1f0c229
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/manual/rhi/cubemap_render/cubemap_mrt.frag b/tests/manual/rhi/cubemap_render/cubemap_mrt.frag
new file mode 100644
index 0000000000..06a08f6cd6
--- /dev/null
+++ b/tests/manual/rhi/cubemap_render/cubemap_mrt.frag
@@ -0,0 +1,28 @@
+#version 440
+
+layout(location = 0) out vec4 c0;
+layout(location = 1) out vec4 c1;
+layout(location = 2) out vec4 c2;
+layout(location = 3) out vec4 c3;
+layout(location = 4) out vec4 c4;
+layout(location = 5) out vec4 c5;
+
+layout(std140, binding = 0) uniform buf {
+    mat4 mvp;
+    vec3 color0;
+    vec3 color1;
+    vec3 color2;
+    vec3 color3;
+    vec3 color4;
+    vec3 color5;
+} ubuf;
+
+void main()
+{
+    c0 = vec4(ubuf.color0, 1.0);
+    c1 = vec4(ubuf.color1, 1.0);
+    c2 = vec4(ubuf.color2, 1.0);
+    c3 = vec4(ubuf.color3, 1.0);
+    c4 = vec4(ubuf.color4, 1.0);
+    c5 = vec4(ubuf.color5, 1.0);
+}