D3D12: Fix 'ShaderEffect in a ShaderEffectSource as property value'

Import (and clean up) the dropshadow from the shadereffects example.
This is very useful since it tests a lot more paths and cases than
the wobble.

To overcome the issue of not having some of functionality available before
the item is added to a window, make QQuickGenericShaderEffect smarter and
enhance the documentation.

The handling of vertical mirroring is revised. The GLSL and HLSL version of
the dropshadow shaders produce correct, identical output now.

Change-Id: I94800997bfba781140d80720eb6f340cda480747
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

9 files changed, 155 insertions, 15 deletions

diff --git a/tests/manual/nodetypes/Effects.qml b/tests/manual/nodetypes/Effects.qml
index 8af9a5eb95..4503c49df1 100644
--- a/tests/manual/nodetypes/Effects.qml
+++ b/tests/manual/nodetypes/Effects.qml
@@ -47,26 +47,39 @@ Item {
         anchors.margins: 10
         anchors.fill: parent
         Image {
-            id: image
+            id: image1
             source: "qrc:/qt.png"
         }
         ShaderEffectSource {
-            id: effectSource
-            sourceItem: image
+            id: effectSource1
+            sourceItem: image1
             hideSource: true
         }
-        ShaderEffect {
-            width: image.width
-            height: image.height
+        ShaderEffect { // wobble
+            id: eff
+            width: image1.width
+            height: image1.height
             anchors.centerIn: parent
 
-            property variant source: effectSource
+            property variant source: effectSource1
             property real amplitude: 0.04 * 0.2
             property real frequency: 20
             property real time: 0
 
             NumberAnimation on time { loops: Animation.Infinite; from: 0; to: Math.PI * 2; duration: 600 }
 
+            property bool customVertexShader: false // the effect is fine with the default vs, but toggle this to test
+
+            property string glslVertexShader:
+                "uniform highp mat4 qt_Matrix;" +
+                "attribute highp vec4 qt_Vertex;" +
+                "attribute highp vec2 qt_MultiTexCoord0;" +
+                "varying highp vec2 qt_TexCoord0;" +
+                "void main() {" +
+                "   qt_TexCoord0 = qt_MultiTexCoord0;" +
+                "   gl_Position = qt_Matrix * qt_Vertex;" +
+                "}"
+
             property string glslFragmentShader:
                 "uniform sampler2D source;" +
                 "uniform highp float amplitude;" +
@@ -82,11 +95,93 @@ Item {
             property string hlslVertexShaderByteCode: "qrc:/vs_wobble.cso"
             property string hlslPixelShaderByteCode: "qrc:/ps_wobble.cso"
 
-            // This effect does not need a custom vertex shader but have one with HLSL just to test that path as well.
-            vertexShader: shaderType === ShaderEffect.GLSL ? ""
-                                                           : (shaderType === ShaderEffect.HLSL ? hlslVertexShaderByteCode : "")
-            fragmentShader: shaderType === ShaderEffect.GLSL ? glslFragmentShader
-                                                             : (shaderType === ShaderEffect.HLSL ? hlslPixelShaderByteCode : "")
+            vertexShader: customVertexShader ? (shaderType === ShaderEffect.HLSL ? hlslVertexShaderByteCode : (shaderType === ShaderEffect.GLSL ? glslVertexShader : "")) : ""
+
+            fragmentShader: shaderType === ShaderEffect.HLSL ? hlslPixelShaderByteCode : (shaderType === ShaderEffect.GLSL ? glslFragmentShader : "")
+        }
+
+        Image {
+            id: image2
+            source: "qrc:/face-smile.png"
+        }
+        ShaderEffectSource {
+            id: effectSource2
+            sourceItem: image2
+            hideSource: true
+        }
+        ShaderEffect { // dropshadow
+            id: eff2
+            width: image2.width
+            height: image2.height
+            scale: 2
+            x: 40
+            y: 40
+
+            property variant source: effectSource2
+
+            property string glslShaderPass1: "
+                uniform lowp float qt_Opacity;
+                uniform sampler2D source;
+                uniform highp vec2 delta;
+                varying highp vec2 qt_TexCoord0;
+                void main() {
+                    gl_FragColor = (0.0538 * texture2D(source, qt_TexCoord0 - 3.182 * delta)
+                        + 0.3229 * texture2D(source, qt_TexCoord0 - 1.364 * delta)
+                        + 0.2466 * texture2D(source, qt_TexCoord0)
+                        + 0.3229 * texture2D(source, qt_TexCoord0 + 1.364 * delta)
+                        + 0.0538 * texture2D(source, qt_TexCoord0 + 3.182 * delta)) * qt_Opacity;
+                }"
+            property string glslShaderPass2: "
+                uniform lowp float qt_Opacity;
+                uniform highp vec2 offset;
+                uniform sampler2D source;
+                uniform sampler2D shadow;
+                uniform highp float darkness;
+                uniform highp vec2 delta;
+                varying highp vec2 qt_TexCoord0;
+                void main() {
+                    lowp vec4 fg = texture2D(source, qt_TexCoord0);
+                    lowp vec4 bg = texture2D(shadow, qt_TexCoord0 + delta);
+                    gl_FragColor = (fg + vec4(0., 0., 0., darkness * bg.a) * (1. - fg.a)) * qt_Opacity;
+                }"
+
+            property variant shadow: ShaderEffectSource {
+                sourceItem: ShaderEffect {
+                    width: eff2.width
+                    height: eff2.height
+                    property variant delta: Qt.size(0.0, 1.0 / height)
+                    property variant source: ShaderEffectSource {
+                        sourceItem: ShaderEffect {
+                            id: innerEff
+                            width: eff2.width
+                            height: eff2.height
+                            property variant delta: Qt.size(1.0 / width, 0.0)
+                            property variant source: effectSource2
+                            fragmentShader: shaderType === ShaderEffect.HLSL ? "qrc:/ps_shadow1.cso" : (shaderType === ShaderEffect.GLSL ? eff2.glslShaderPass1 : "")
+                        }
+                    }
+                    fragmentShader: shaderType === ShaderEffect.HLSL ? "qrc:/ps_shadow1.cso" : (shaderType === ShaderEffect.GLSL ? eff2.glslShaderPass1: "")
+                }
+            }
+            property real angle: 0
+            property variant offset: Qt.point(5.0 * Math.cos(angle), 5.0 * Math.sin(angle))
+            NumberAnimation on angle { loops: Animation.Infinite; from: 0; to: Math.PI * 2; duration: 6000 }
+            property variant delta: Qt.size(offset.x / width, offset.y / height)
+            property real darkness: 0.5
+            fragmentShader: shaderType === ShaderEffect.HLSL ? "qrc:/ps_shadow2.cso" : (shaderType === ShaderEffect.GLSL ? glslShaderPass2 : "")
+        }
+
+        Column {
+            anchors.bottom: parent.bottom
+            Text {
+                color: "yellow"
+                font.pointSize: 24
+                text: "Shader effect is " + (eff.shaderType === ShaderEffect.HLSL ? "HLSL" : (eff.shaderType === ShaderEffect.GLSL ? "GLSL" : "UNKNOWN")) + " based";
+            }
+            Text {
+                // check the inner shader effect's properties as those only get updated later on, once a window gets associated
+                text: innerEff.shaderType + " " + innerEff.shaderCompilationType + " " + innerEff.shaderSourceType
+            }
         }
     }
 }
diff --git a/tests/manual/nodetypes/hlslcompile.bat b/tests/manual/nodetypes/hlslcompile.bat
index 8f7ca86069..b24824e324 100644
--- a/tests/manual/nodetypes/hlslcompile.bat
+++ b/tests/manual/nodetypes/hlslcompile.bat
@@ -1,2 +1,4 @@
-fxc /E VS_Wobble /T vs_5_0 /Fo vs_wobble.cso effects.hlsl
-fxc /E PS_Wobble /T ps_5_0 /Fo ps_wobble.cso effects.hlsl
+fxc /E VS_Wobble /T vs_5_0 /Fo vs_wobble.cso wobble.hlsl
+fxc /E PS_Wobble /T ps_5_0 /Fo ps_wobble.cso wobble.hlsl
+fxc /E PS_Shadow1 /T ps_5_0 /Fo ps_shadow1.cso shadow1.hlsl
+fxc /E PS_Shadow2 /T ps_5_0 /Fo ps_shadow2.cso shadow2.hlsl
diff --git a/tests/manual/nodetypes/nodetypes.pro b/tests/manual/nodetypes/nodetypes.pro
index 51a6ac3e5a..43b79323a8 100644
--- a/tests/manual/nodetypes/nodetypes.pro
+++ b/tests/manual/nodetypes/nodetypes.pro
@@ -5,4 +5,5 @@ SOURCES += nodetypes.cpp
 RESOURCES += nodetypes.qrc
 
 OTHER_FILES += main.qml Rects.qml LotsOfRects.qml \
-               Images.qml Text.qml Animators.qml Layers.qml Effects.qml effects.hlsl
+               Images.qml Text.qml Animators.qml Layers.qml Effects.qml \
+               wobble.hlsl shadow1.hlsl shadow2.hlsl
diff --git a/tests/manual/nodetypes/nodetypes.qrc b/tests/manual/nodetypes/nodetypes.qrc
index f6c007e3f3..64bd503319 100644
--- a/tests/manual/nodetypes/nodetypes.qrc
+++ b/tests/manual/nodetypes/nodetypes.qrc
@@ -13,5 +13,7 @@
         <file>shadow.png</file>
         <file>vs_wobble.cso</file>
         <file>ps_wobble.cso</file>
+        <file>ps_shadow1.cso</file>
+        <file>ps_shadow2.cso</file>
     </qresource>
 </RCC>
diff --git a/tests/manual/nodetypes/ps_shadow1.cso b/tests/manual/nodetypes/ps_shadow1.cso
new file mode 100644
index 0000000000..b6fbe3f3c2
--- /dev/null
+++ b/tests/manual/nodetypes/ps_shadow1.cso
diff --git a/tests/manual/nodetypes/ps_shadow2.cso b/tests/manual/nodetypes/ps_shadow2.cso
new file mode 100644
index 0000000000..ab8cb63f34
--- /dev/null
+++ b/tests/manual/nodetypes/ps_shadow2.cso
diff --git a/tests/manual/nodetypes/shadow1.hlsl b/tests/manual/nodetypes/shadow1.hlsl
new file mode 100644
index 0000000000..ff3f4b6fd5
--- /dev/null
+++ b/tests/manual/nodetypes/shadow1.hlsl
@@ -0,0 +1,18 @@
+cbuffer ConstantBuffer : register(b0)
+{
+    float4x4 qt_Matrix;
+    float qt_Opacity;
+    float2 delta;
+};
+
+Texture2D source : register(t0);
+SamplerState sourceSampler : register(s0);
+
+float4 PS_Shadow1(float4 position : SV_POSITION, float2 coord : TEXCOORD0) : SV_TARGET
+{
+    return (0.0538 * source.Sample(sourceSampler, coord - 3.182 * delta)
+        + 0.3229 * source.Sample(sourceSampler, coord - 1.364 * delta)
+        + 0.2466 * source.Sample(sourceSampler, coord)
+        + 0.3229 * source.Sample(sourceSampler, coord + 1.364 * delta)
+        + 0.0538 * source.Sample(sourceSampler, coord + 3.182 * delta)) * qt_Opacity;
+}
diff --git a/tests/manual/nodetypes/shadow2.hlsl b/tests/manual/nodetypes/shadow2.hlsl
new file mode 100644
index 0000000000..eaa30cd988
--- /dev/null
+++ b/tests/manual/nodetypes/shadow2.hlsl
@@ -0,0 +1,22 @@
+cbuffer ConstantBuffer : register(b0)
+{
+    float4x4 qt_Matrix;
+    float qt_Opacity;
+    float2 offset;
+    float darkness;
+    float2 delta;
+};
+
+Texture2D source : register(t0);
+Texture2D shadow : register(t1);
+SamplerState samp : register(s0);
+// Use the same sampler for both textures. In fact the engine will create an extra static sampler
+// in any case (to match the number of textures) due to some internals, but that won't hurt, the
+// shader works either way.
+
+float4 PS_Shadow2(float4 position : SV_POSITION, float2 coord : TEXCOORD0) : SV_TARGET
+{
+    float4 fg = source.Sample(samp, coord);
+    float4 bg = shadow.Sample(samp, coord + delta);
+    return (fg + float4(0.0, 0.0, 0.0, darkness * bg.a) * (1.0 - fg.a)) * qt_Opacity;
+}
diff --git a/tests/manual/nodetypes/effects.hlsl b/tests/manual/nodetypes/wobble.hlsl
index 203dbda7f2..203dbda7f2 100644
--- a/tests/manual/nodetypes/effects.hlsl
+++ b/tests/manual/nodetypes/wobble.hlsl