Improve the custom material multiview strategy

Do not flood the user (and our implementation, when it comes to enums
and such) with the _ARRAY variants. The original idea, where
DEPTH_TEXTURE would remain a sampler2D even in multiview mode, and would
still be functional with the left eye texture, is not feasible to do for
all the 3D APIs. And with that out of the picture, we can just let
DEPTH_TEXTURE expand to qt_depthTexture or qt_depthTextureArray
depending on having multiview mode enabled.

The details do not change, the user still needs to be aware of the type
(sampler2D vs sampler2DArray) and write code such as. However, the name
does not need to be varied now (DEPTH_TEXTURE in both cases)

  #if QSHADER_VIEW_COUNT >= 2
    vec4 depthSample = texture(DEPTH_TEXTURE, vec3(uv, VIEW_INDEX));
  #else
    vec4 depthSample = texture(DEPTH_TEXTURE, uv);
  #endif

Applies to SCREEN_TEXTURE and AO_TEXTURE as well, and, in the future, to
INPUT (qt_inputTexture[Array]) for postproc. effects.

Change-Id: I768fe9d48730f2d59023f86647d33365a52e53ae
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

10 files changed, 63 insertions, 108 deletions

diff --git a/src/quick3d/doc/src/qtquick3d-custom.qdoc b/src/quick3d/doc/src/qtquick3d-custom.qdoc
index 2d45dcb9..ea1598d8 100644
--- a/src/quick3d/doc/src/qtquick3d-custom.qdoc
+++ b/src/quick3d/doc/src/qtquick3d-custom.qdoc
@@ -1310,20 +1310,6 @@ void MAIN()
 Here the rectangle is textured with \c SCREEN_TEXTURE, while replacing transparent pixels
 with purple.
 
-Custom materials written to be used with Qt Quick 3D XR should consider relying
-on \c DEPTH_TEXTURE_ARRAY instead of \c DEPTH_TEXTURE, and \c
-SCREEN_TEXTURE_ARRAY instead of \c SCREEN_TEXTURE. This needs to be ifdefed so
-that referencing the texture array is only done when multiview rendering is in
-use:
-
-\badcode
-    #if QSHADER_VIEW_COUNT >= 2
-        vec4 depthSample = texture(DEPTH_TEXTURE_ARRAY, vec3(uv, VIEW_INDEX));
-    #else
-        vec4 depthSample = texture(DEPTH_TEXTURE, uv);
-    #endif
-\endcode
-
 \section2 Light processor functions
 
 An advanced feature of \l CustomMaterial is the ability to define functions in the
diff --git a/src/quick3d/qquick3dcustommaterial.cpp b/src/quick3d/qquick3dcustommaterial.cpp
index 73c2a18e..4329258d 100644
--- a/src/quick3d/qquick3dcustommaterial.cpp
+++ b/src/quick3d/qquick3dcustommaterial.cpp
@@ -1098,6 +1098,16 @@ QT_BEGIN_NAMESPACE
             BASE_COLOR = vec4(vec3(c), alpha);
         }
     \endcode
+    With multiview rendering, \c SCREEN_TEXTURE is a \c sampler2DArray. Use
+    \c VIEW_INDEX to select the layer to use. For VR/AR applications that wish to
+    support both types of rendering, the portable approach is the following:
+    \badcode
+        #if QSHADER_VIEW_COUNT >= 2
+            vec4 c = texture(SCREEN_TEXTURE, vec3(uv, VIEW_INDEX));
+        #else
+            vec4 c = texture(SCREEN_TEXTURE, uv);
+        #endif
+    \endcode
 
     \li \c SCREEN_MIP_TEXTURE - Identical to \c SCREEN_TEXTURE in most ways,
     the difference being that this texture has mipmaps generated. This can be
@@ -1107,23 +1117,7 @@ QT_BEGIN_NAMESPACE
     relying on the texture mip levels (e.g. using \c textureLod in the shader)
     is implemented by the custom material.
 
-    \li \c SCREEN_TEXTURE_ARRAY - When present, a texture array (sampler2DArray)
-    with the color buffer from a rendering pass containing the contents of the
-    scene excluding any transparent materials or any materials also using the
-    screen texture is exposed to the shader under this name. Use \c VIEW_INDEX
-    to select the layer to use. When multiview rendering is not active, this
-    should not relied on. Therefore, the portable approach is the following: \badcode
-        #if QSHADER_VIEW_COUNT >= 2
-            vec4 c = texture(SCREEN_TEXTURE_ARRAY, vec3(uv, VIEW_INDEX));
-        #else
-            vec4 c = texture(SCREEN_TEXTURE, uv);
-        #endif
-    \endcode
-
-    \li \c SCREEN_MIP_TEXTURE_ARRAY - Identical to \c SCREEN_TEXTURE_ARRAY,
-    except that the texture has mipmaps generated.
-
-    \li \c DEPTH_TEXTURE - When present, a texture (sampler2D) with the
+    \li \c DEPTH_TEXTURE - When present, a texture (\c sampler2D) with the
     (non-linearized) depth buffer contents is exposed to the shader under this
     name. Only opaque objects are included.
     For example, a fragment shader could contain the following: \badcode
@@ -1137,14 +1131,12 @@ QT_BEGIN_NAMESPACE
         float d = 2.0 * zNear * zFar / (zFar + zNear - z_n * zRange);
         d /= zFar;
     \endcode
-
-    \li \c DEPTH_TEXTURE_ARRAY - When present, a texture array (sampler2DArray)
-    with the (non-linearized) depth buffer contents is exposed to the shader
-    under this name. Only opaque objects are included. Use \c VIEW_INDEX to
-    select the layer to use. When multiview rendering is not active, this
-    should not relied on. Therefore, the portable approach is the following: \badcode
+    With multiview rendering, \c DEPTH_TEXTURE is a \c sampler2DArray. Use
+    \c VIEW_INDEX to select the layer to use. For VR/AR applications that wish to
+    support both types of rendering, the portable approach is the following:
+    \badcode
         #if QSHADER_VIEW_COUNT >= 2
-            vec4 depthSample = texture(DEPTH_TEXTURE_ARRAY, vec3(uv, VIEW_INDEX));
+            vec4 depthSample = texture(DEPTH_TEXTURE, vec3(uv, VIEW_INDEX));
         #else
             vec4 depthSample = texture(DEPTH_TEXTURE, uv);
         #endif
@@ -1162,16 +1154,14 @@ QT_BEGIN_NAMESPACE
         vec2 aoUV = (FRAGCOORD.xy) / vec2(aoSize);
         float aoFactor = texture(AO_TEXTURE, aoUV).x;
     \endcode
-
-    \li \c AO_TEXTURE_ARRAY - Available only when multiview rendering is in use.
-    Similar to \c AO_TEXTURE, but this is a 2D texture array (sampler2DArray).
-    Use \c VIEW_INDEX as the layer (the third coordinate in the \c uv argument in
-    \c{texture()}). Portable custom materials that wish to function both with and
-    without multiview rendering, can do the following: \badcode
+    With multiview rendering, \c AO_TEXTURE is a \c sampler2DArray. Use
+    \c VIEW_INDEX to select the layer to use. For VR/AR applications that wish to
+    support both types of rendering, the portable approach is the following:
+    \badcode
         #if QSHADER_VIEW_COUNT >= 2
-            ivec2 aoSize = textureSize(AO_TEXTURE_ARRAY, 0).xy;
+            ivec2 aoSize = textureSize(AO_TEXTURE, 0).xy;
             vec2 aoUV = (FRAGCOORD.xy) / vec2(aoSize);
-            float aoFactor = texture(AO_TEXTURE_ARRAY, vec3(aoUV, VIEW_INDEX)).x;
+            float aoFactor = texture(AO_TEXTURE, vec3(aoUV, VIEW_INDEX)).x;
         #else
             ivec2 aoSize = textureSize(AO_TEXTURE, 0);
             vec2 aoUV = (FRAGCOORD.xy) / vec2(aoSize);
@@ -1193,8 +1183,8 @@ QT_BEGIN_NAMESPACE
     \li \c VIEW_INDEX - When used in the custom shader code, this is a
     (non-interpolated) uint variable. When multiview rendering is not used, the
     value is always 0. With multiview rendering, the value is the current view
-    index (e.g., gl_ViewIndex). Useful in particular in combination with \c
-    DEPTH_TEXTURE_ARRAY and similar.
+    index (e.g., gl_ViewIndex). Useful in particular in combination with
+    \c DEPTH_TEXTURE and similar when multiview rendering is enabled.
 
     \endlist
 
@@ -1602,14 +1592,6 @@ static void setCustomMaterialFlagsFromShader(QSSGRenderCustomMaterial *material,
         material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::Morphing, true);
     if (meta.flags.testFlag(QSSGCustomShaderMetaData::UsesViewIndex))
         material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::ViewIndex, true);
-    if (meta.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTextureArray))
-        material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::DepthTextureArray, true);
-    if (meta.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenTextureArray))
-        material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::ScreenTextureArray, true);
-    if (meta.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenMipTextureArray))
-        material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::ScreenMipTextureArray, true);
-    if (meta.flags.testFlag(QSSGCustomShaderMetaData::UsesAoTextureArray))
-        material->m_renderFlags.setFlag(QSSGRenderCustomMaterial::RenderFlag::AoTextureArray, true);
 
     // vertex only
     if (meta.flags.testFlag(QSSGCustomShaderMetaData::OverridesPosition))
diff --git a/src/quick3d/qquick3deffect.cpp b/src/quick3d/qquick3deffect.cpp
index e883cebb..db5905be 100644
--- a/src/quick3d/qquick3deffect.cpp
+++ b/src/quick3d/qquick3deffect.cpp
@@ -812,11 +812,8 @@ QSSGRenderGraphObject *QQuick3DEffect::updateSpatialNode(QSSGRenderGraphObject *
                                                                                       uniforms, builtinVertexOutputs);
                     }
 
-                    if (result.second.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTexture)
-                        || result.second.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTextureArray))
-                    {
+                    if (result.second.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTexture))
                         effectNode->requiresDepthTexture = true;
-                    }
 
                     code = result.first + shaderCodeMeta;
 
diff --git a/src/runtimerender/graphobjects/qssgrendercustommaterial_p.h b/src/runtimerender/graphobjects/qssgrendercustommaterial_p.h
index 2e8432da..299c8245 100644
--- a/src/runtimerender/graphobjects/qssgrendercustommaterial_p.h
+++ b/src/runtimerender/graphobjects/qssgrendercustommaterial_p.h
@@ -105,11 +105,7 @@ struct Q_QUICK3DRUNTIMERENDER_EXPORT QSSGRenderCustomMaterial : public QSSGRende
         Lightmap = 1 << 10,
         Skinning = 1 << 11,
         Morphing = 1 << 12,
-        ViewIndex = 1 << 13,
-        DepthTextureArray = 1 << 14,
-        ScreenTextureArray = 1 << 15,
-        ScreenMipTextureArray = 1 << 16,
-        AoTextureArray = 1 << 17
+        ViewIndex = 1 << 13
     };
     Q_DECLARE_FLAGS(RenderFlags, RenderFlag)
 
diff --git a/src/runtimerender/qssgshadermaterialadapter.cpp b/src/runtimerender/qssgshadermaterialadapter.cpp
index d2598e03..22f5f5ba 100644
--- a/src/runtimerender/qssgshadermaterialadapter.cpp
+++ b/src/runtimerender/qssgshadermaterialadapter.cpp
@@ -723,14 +723,10 @@ static const QSSGCustomMaterialVariableSubstitution qssg_var_subst_tab[] = {
     { "IBL_PROBE", "qt_iblProbeProcessor", false },
 
     // textures
-    { "SCREEN_TEXTURE", "qt_screenTexture", false },
-    { "SCREEN_MIP_TEXTURE", "qt_screenTexture", false }, // same resource as SCREEN_TEXTURE under the hood
-    { "SCREEN_TEXTURE_ARRAY", "qt_screenTextureArray", false },
-    { "SCREEN_MIP_TEXTURE_ARRAY", "qt_screenTextureArray", false },
-    { "DEPTH_TEXTURE", "qt_depthTexture", false },
-    { "DEPTH_TEXTURE_ARRAY", "qt_depthTextureArray", false },
-    { "AO_TEXTURE", "qt_aoTexture", false },
-    { "AO_TEXTURE", "qt_aoTextureArray", false },
+    { "SCREEN_TEXTURE", "qt_screenTexture", true },
+    { "SCREEN_MIP_TEXTURE", "qt_screenTexture", true }, // same resource as SCREEN_TEXTURE under the hood
+    { "DEPTH_TEXTURE", "qt_depthTexture", true },
+    { "AO_TEXTURE", "qt_aoTexture", true },
     { "IBL_TEXTURE", "qt_lightProbe", false },
     { "LIGHTMAP", "qt_lightmap", false },
 
@@ -975,8 +971,6 @@ QSSGShaderCustomMaterialAdapter::prepareCustomShader(QByteArray &dst,
                     md.flags |= QSSGCustomShaderMetaData::UsesDepthTexture;
                 else if (trimmedId == QByteArrayLiteral("AO_TEXTURE"))
                     md.flags |= QSSGCustomShaderMetaData::UsesAoTexture;
-                else if (trimmedId == QByteArrayLiteral("AO_TEXTURE_ARRAY"))
-                    md.flags |= QSSGCustomShaderMetaData::UsesAoTextureArray;
                 else if (trimmedId == QByteArrayLiteral("POSITION"))
                     md.flags |= QSSGCustomShaderMetaData::OverridesPosition;
                 else if (trimmedId == QByteArrayLiteral("PROJECTION_MATRIX"))
@@ -993,19 +987,20 @@ QSSGShaderCustomMaterialAdapter::prepareCustomShader(QByteArray &dst,
                     md.flags |= QSSGCustomShaderMetaData::UsesLightmap;
                 else if (trimmedId == QByteArrayLiteral("VIEW_INDEX"))
                     md.flags |= QSSGCustomShaderMetaData::UsesViewIndex;
-                else if (trimmedId == QByteArrayLiteral("DEPTH_TEXTURE_ARRAY"))
-                    md.flags |= QSSGCustomShaderMetaData::UsesDepthTextureArray;
-                else if (trimmedId == QByteArrayLiteral("SCREEN_TEXTURE_ARRAY"))
-                    md.flags |= QSSGCustomShaderMetaData::UsesScreenTextureArray;
-                else if (trimmedId == QByteArrayLiteral("SCREEN_MIP_TEXTURE_ARRAY"))
-                    md.flags |= QSSGCustomShaderMetaData::UsesScreenMipTextureArray;
 
                 for (const QSSGCustomMaterialVariableSubstitution &subst : qssg_var_subst_tab) {
                     if (trimmedId == subst.builtin) {
                         QByteArray newExpr;
                         newExpr.assign(subst.actualName);
-                        if (subst.multiViewDependent && multiViewCompatible)
-                            newExpr += QByteArrayLiteral("[qt_viewIndex]");
+                        if (subst.multiViewDependent && multiViewCompatible) {
+                            if (subst.builtin.endsWith(QByteArrayLiteral("_TEXTURE"))
+                                || subst.builtin == QByteArrayLiteral("INPUT"))
+                            {
+                                newExpr += QByteArrayLiteral("Array"); // e.g. qt_depthTexture -> qt_depthTextureArray
+                            } else {
+                                newExpr += QByteArrayLiteral("[qt_viewIndex]"); // e.g. qt_viewProjectionMatrix -> qt_viewProjectionMatrix[qt_viewIndex]
+                            }
+                        }
                         id.replace(subst.builtin, newExpr); // replace, not assignment, to keep whitespace etc.
                         if (trimmedId == QByteArrayLiteral("BONE_TRANSFORMS")) {
                             useJointTexState = 0;
@@ -1099,22 +1094,28 @@ QSSGShaderCustomMaterialAdapter::prepareCustomShader(QByteArray &dst,
     // sampler2DArray binding point and vice versa. Therefore it is up to the
     // shader snippet to ifdef with QSHADER_VIEW_COUNT if it wants to support
     // both multiview and non-multiview rendering.
-    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTexture) && !multiViewCompatible)
-        allUniforms.append({ "sampler2D", "qt_depthTexture" });
-    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTextureArray) && multiViewCompatible)
-        allUniforms.append({ "sampler2DArray", "qt_depthTextureArray" });
+    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesDepthTexture)) {
+        if (multiViewCompatible)
+            allUniforms.append({ "sampler2DArray", "qt_depthTextureArray" });
+        else
+            allUniforms.append({ "sampler2D", "qt_depthTexture" });
+    }
 
     // And the same pattern for qt_screenTexture(Array).
-    if ((md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenTexture) || md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenMipTexture)) && !multiViewCompatible)
-        allUniforms.append({ "sampler2D", "qt_screenTexture" });
-    if ((md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenTextureArray) || md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenMipTextureArray)) && multiViewCompatible)
-        allUniforms.append({ "sampler2DArray", "qt_screenTextureArray" });
+    if ((md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenTexture) || md.flags.testFlag(QSSGCustomShaderMetaData::UsesScreenMipTexture))) {
+        if (multiViewCompatible)
+            allUniforms.append({ "sampler2DArray", "qt_screenTextureArray" });
+        else
+            allUniforms.append({ "sampler2D", "qt_screenTexture" });
+    }
 
     // And for SSAO.
-    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesAoTexture))
-        allUniforms.append({ "sampler2D", "qt_aoTexture" });
-    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesAoTextureArray))
-        allUniforms.append({ "sampler2DArray", "qt_aoTextureArray" });
+    if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesAoTexture)) {
+        if (multiViewCompatible)
+            allUniforms.append({ "sampler2DArray", "qt_aoTextureArray" });
+        else
+            allUniforms.append({ "sampler2D", "qt_aoTexture" });
+    }
 
     if (md.flags.testFlag(QSSGCustomShaderMetaData::UsesLightmap))
         allUniforms.append({ "sampler2D", "qt_lightmap" });
diff --git a/src/runtimerender/rendererimpl/qssglayerrenderdata.cpp b/src/runtimerender/rendererimpl/qssglayerrenderdata.cpp
index e13e7fa8..13ba375a 100644
--- a/src/runtimerender/rendererimpl/qssglayerrenderdata.cpp
+++ b/src/runtimerender/rendererimpl/qssglayerrenderdata.cpp
@@ -1368,9 +1368,6 @@ QSSGDefaultMaterialPreparationResult QSSGLayerRenderData::prepareCustomMaterialF
     if (inMaterial.m_renderFlags.testFlag(QSSGRenderCustomMaterial::RenderFlag::DepthTexture))
         ioFlags.setRequiresDepthTexture(true);
 
-    if (inMaterial.m_renderFlags.testFlag(QSSGRenderCustomMaterial::RenderFlag::DepthTextureArray))
-        ioFlags.setRequiresDepthTexture(true);
-
     if (inMaterial.m_renderFlags.testFlag(QSSGRenderCustomMaterial::RenderFlag::AoTexture)) {
         ioFlags.setRequiresDepthTexture(true);
         ioFlags.setRequiresSsaoPass(true);
diff --git a/src/runtimerender/resourcemanager/qssgrendershaderlibrarymanager_p.h b/src/runtimerender/resourcemanager/qssgrendershaderlibrarymanager_p.h
index 1a4938b6..317c43e3 100644
--- a/src/runtimerender/resourcemanager/qssgrendershaderlibrarymanager_p.h
+++ b/src/runtimerender/resourcemanager/qssgrendershaderlibrarymanager_p.h
@@ -48,11 +48,7 @@ struct QSSGCustomShaderMetaData
         UsesLightmap = 1 << 10,
         UsesSkinning = 1 << 11,
         UsesMorphing = 1 << 12,
-        UsesViewIndex = 1 << 13,
-        UsesDepthTextureArray = 1 << 14,
-        UsesScreenTextureArray = 1 << 15,
-        UsesScreenMipTextureArray = 1 << 16,
-        UsesAoTextureArray = 1 << 17
+        UsesViewIndex = 1 << 13
     };
     Q_DECLARE_FLAGS(Flags, Flag)
 
diff --git a/tests/baseline/data/custommaterial/custom_unshaded_depth_array.frag b/tests/baseline/data/custommaterial/custom_unshaded_depth_array.frag
index ba25ff00..911fbfef 100644
--- a/tests/baseline/data/custommaterial/custom_unshaded_depth_array.frag
+++ b/tests/baseline/data/custommaterial/custom_unshaded_depth_array.frag
@@ -6,8 +6,8 @@ void MAIN()
     // not really using the texture array version, unless multiview rendering is active,
     // nonetheless this test verifies that QSHADER_VIEW_COUNT is defined etc.
 #if QSHADER_VIEW_COUNT >= 2
-    vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE_ARRAY, 0).xy);
-    vec4 depthSample = texture(DEPTH_TEXTURE_ARRAY, vec3(uv, VIEW_INDEX));
+    vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE, 0).xy);
+    vec4 depthSample = texture(DEPTH_TEXTURE, vec3(uv, VIEW_INDEX));
 #else
     vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE, 0));
     vec4 depthSample = texture(DEPTH_TEXTURE, uv);
diff --git a/tests/manual/qmlxr/testscenes/custom_unshaded_depth.frag b/tests/manual/qmlxr/testscenes/custom_unshaded_depth.frag
index 48f637aa..b73bb4c6 100644
--- a/tests/manual/qmlxr/testscenes/custom_unshaded_depth.frag
+++ b/tests/manual/qmlxr/testscenes/custom_unshaded_depth.frag
@@ -4,8 +4,8 @@
 void MAIN()
 {
 #if QSHADER_VIEW_COUNT >= 2
-    vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE_ARRAY, 0).xy);
-    vec4 depthSample = texture(DEPTH_TEXTURE_ARRAY, vec3(uv, VIEW_INDEX));
+    vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE, 0).xy);
+    vec4 depthSample = texture(DEPTH_TEXTURE, vec3(uv, VIEW_INDEX));
 #else
     vec2 uv = (gl_FragCoord.xy) / vec2(textureSize(DEPTH_TEXTURE, 0));
     vec4 depthSample = texture(DEPTH_TEXTURE, uv);
diff --git a/tests/manual/qmlxr/testscenes/customsimpletexturescreen.frag b/tests/manual/qmlxr/testscenes/customsimpletexturescreen.frag
index afcbe686..5d1ee70f 100644
--- a/tests/manual/qmlxr/testscenes/customsimpletexturescreen.frag
+++ b/tests/manual/qmlxr/testscenes/customsimpletexturescreen.frag
@@ -10,7 +10,7 @@ void MAIN()
     if (FRAMEBUFFER_Y_UP < 0.0)
         screencoord.y = 1.0 - screencoord.y;
 #if QSHADER_VIEW_COUNT >= 2
-    BASE_COLOR *= texture(SCREEN_TEXTURE_ARRAY, vec3(screencoord, VIEW_INDEX));
+    BASE_COLOR *= texture(SCREEN_TEXTURE, vec3(screencoord, VIEW_INDEX));
 #else
     BASE_COLOR *= texture(SCREEN_TEXTURE, screencoord);
 #endif