Fix env-map less rendering

Assign texture units to env map samplers even if they are not used.
Remove previous work around from pbr material.

Change-Id: I5060bfb61c4658339d2b74df71574c39cddfeb18
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

3 files changed, 7 insertions, 28 deletions

diff --git a/src/extras/defaults/qmetalroughmaterial.cpp b/src/extras/defaults/qmetalroughmaterial.cpp
index de21268f1..f52437769 100644
--- a/src/extras/defaults/qmetalroughmaterial.cpp
+++ b/src/extras/defaults/qmetalroughmaterial.cpp
@@ -61,8 +61,6 @@ namespace Qt3DExtras {
 
 QMetalRoughMaterialPrivate::QMetalRoughMaterialPrivate()
     : QMaterialPrivate()
-    , m_environmentIrradianceTexture(new QTexture2D())
-    , m_environmentSpecularTexture(new QTexture2D())
     , m_baseColorParameter(new QParameter(QStringLiteral("baseColor"), QColor("grey")))
     , m_metalnessParameter(new QParameter(QStringLiteral("metalness"), 0.0f))
     , m_roughnessParameter(new QParameter(QStringLiteral("roughness"), 0.0f))
@@ -72,8 +70,6 @@ QMetalRoughMaterialPrivate::QMetalRoughMaterialPrivate()
     , m_ambientOcclusionMapParameter(new QParameter(QStringLiteral("ambientOcclusionMap"), QVariant()))
     , m_normalMapParameter(new QParameter(QStringLiteral("normalMap"), QVariant()))
     , m_textureScaleParameter(new QParameter(QStringLiteral("texCoordScale"), 1.0f))
-    , m_environmentIrradianceParameter(new QParameter(QStringLiteral("envLight.irradiance"), m_environmentIrradianceTexture))
-    , m_environmentSpecularParameter(new QParameter(QStringLiteral("envLight.specular"), m_environmentSpecularTexture))
     , m_metalRoughEffect(new QEffect())
     , m_metalRoughGL3Technique(new QTechnique())
     , m_metalRoughGL3RenderPass(new QRenderPass())
@@ -85,17 +81,6 @@ QMetalRoughMaterialPrivate::QMetalRoughMaterialPrivate()
     , m_metalRoughES3ShaderBuilder(new QShaderProgramBuilder())
     , m_filterKey(new QFilterKey)
 {
-    m_environmentIrradianceTexture->setMagnificationFilter(QAbstractTexture::Linear);
-    m_environmentIrradianceTexture->setMinificationFilter(QAbstractTexture::LinearMipMapLinear);
-    m_environmentIrradianceTexture->setWrapMode(QTextureWrapMode(QTextureWrapMode::Repeat));
-    m_environmentIrradianceTexture->setGenerateMipMaps(true);
-    m_environmentIrradianceTexture->setMaximumAnisotropy(16.0f);
-
-    m_environmentSpecularTexture->setMagnificationFilter(QAbstractTexture::Linear);
-    m_environmentSpecularTexture->setMinificationFilter(QAbstractTexture::LinearMipMapLinear);
-    m_environmentSpecularTexture->setWrapMode(QTextureWrapMode(QTextureWrapMode::Repeat));
-    m_environmentSpecularTexture->setGenerateMipMaps(true);
-    m_environmentSpecularTexture->setMaximumAnisotropy(16.0f);
 }
 
 void QMetalRoughMaterialPrivate::init()
@@ -163,15 +148,6 @@ void QMetalRoughMaterialPrivate::init()
     m_metalRoughEffect->addParameter(m_roughnessParameter);
     m_metalRoughEffect->addParameter(m_textureScaleParameter);
 
-    // Note that even though those parameters are not exposed in the API,
-    // they need to be kept around for now due to a bug in some drivers/GPUs
-    // (at least Intel) which cause issues with unbound textures even if you
-    // don't try to sample from them.
-    // Can probably go away once we generate the shaders and deal in this
-    // case in a better way.
-    m_metalRoughEffect->addParameter(m_environmentIrradianceParameter);
-    m_metalRoughEffect->addParameter(m_environmentSpecularParameter);
-
     q->setEffect(m_metalRoughEffect);
 }
 
diff --git a/src/extras/defaults/qmetalroughmaterial_p.h b/src/extras/defaults/qmetalroughmaterial_p.h
index e12df1a8b..4d8b68320 100644
--- a/src/extras/defaults/qmetalroughmaterial_p.h
+++ b/src/extras/defaults/qmetalroughmaterial_p.h
@@ -81,8 +81,6 @@ public:
 
     void handleTextureScaleChanged(const QVariant &var);
 
-    Qt3DRender::QAbstractTexture *m_environmentIrradianceTexture;
-    Qt3DRender::QAbstractTexture *m_environmentSpecularTexture;
     Qt3DRender::QParameter *m_baseColorParameter;
     Qt3DRender::QParameter *m_metalnessParameter;
     Qt3DRender::QParameter *m_roughnessParameter;
@@ -92,8 +90,6 @@ public:
     Qt3DRender::QParameter *m_ambientOcclusionMapParameter;
     Qt3DRender::QParameter *m_normalMapParameter;
     Qt3DRender::QParameter *m_textureScaleParameter;
-    Qt3DRender::QParameter *m_environmentIrradianceParameter;
-    Qt3DRender::QParameter *m_environmentSpecularParameter;
     Qt3DRender::QEffect *m_metalRoughEffect;
     Qt3DRender::QTechnique *m_metalRoughGL3Technique;
     Qt3DRender::QRenderPass *m_metalRoughGL3RenderPass;
diff --git a/src/render/renderers/opengl/renderer/renderview.cpp b/src/render/renderers/opengl/renderer/renderview.cpp
index 66299e430..8e0c16938 100644
--- a/src/render/renderers/opengl/renderer/renderview.cpp
+++ b/src/render/renderers/opengl/renderer/renderview.cpp
@@ -1060,6 +1060,13 @@ void RenderView::setShaderAndUniforms(RenderCommand *command,
                         setDefaultUniformBlockShaderDataValue(command->m_parameterPack, shader, shaderData, QStringLiteral("envLight"));
                         envLightCount = 1;
                     }
+                } else {
+                    // with some drivers, samplers (like the envbox sampler) need to be bound even though
+                    // they may not be actually used, otherwise draw calls can fail
+                    static const int irradianceId = StringToInt::lookupId(QLatin1String("envLight.irradiance"));
+                    static const int specularId = StringToInt::lookupId(QLatin1String("envLight.specular"));
+                    setUniformValue(command->m_parameterPack, irradianceId, m_renderer->submissionContext()->maxTextureUnitsCount());
+                    setUniformValue(command->m_parameterPack, specularId, m_renderer->submissionContext()->maxTextureUnitsCount());
                 }
                 setUniformValue(command->m_parameterPack, StringToInt::lookupId(QStringLiteral("envLightCount")), envLightCount);
             }