Make mipmap levels and texture comparison work with GLES 3.0+

In ES-only builds (-opengl es2) we hit the QT_OPENGL_ES_2 path which
disables all this. Not ideal since all the support is present in GLES 3.0.

Therefore, stop relying on the ifdef and do runtime checks. This also needs
defining the constants manually since they are not available in gl2.h and our
own ES2 extension headers provide some of these with silly silly suffixes.

Change-Id: I8ad7f5091a371bad1e3c6dc4898342a175016274
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 37 insertions, 50 deletions

diff --git a/src/gui/opengl/qopengltexture.cpp b/src/gui/opengl/qopengltexture.cpp
index db4557d68d..d7d9d3dab6 100644
--- a/src/gui/opengl/qopengltexture.cpp
+++ b/src/gui/opengl/qopengltexture.cpp
@@ -1960,6 +1960,8 @@ QOpenGLTexture *QOpenGLTexturePrivate::createTextureView(QOpenGLTexture::Target
     \value NPOTTextureRepeat Full support for non-power-of-two textures including texture
            repeat modes
     \value Texture1D Support for the 1 dimensional texture target
+    \value TextureComparisonOperators Support for texture comparison operators
+    \value TextureMipMapLevel Support for setting the base and maximum mipmap levels
 */
 
 /*!
@@ -3262,6 +3264,10 @@ bool QOpenGLTexture::hasFeature(Feature feature)
                         && ctx->hasExtension(QByteArrayLiteral("GL_EXT_shadow_funcs")));
             break;
 
+        case TextureMipMapLevel:
+            supported = f.version() >= qMakePair(1, 2);
+            break;
+
         case MaxFeatureFlag:
             break;
         }
@@ -3328,6 +3334,10 @@ bool QOpenGLTexture::hasFeature(Feature feature)
                     || ctx->hasExtension(QByteArrayLiteral("GL_EXT_shadow_samplers"));
             break;
 
+        case TextureMipMapLevel:
+            supported = f.version() >= qMakePair(3, 0);
+            break;
+
         case MaxFeatureFlag:
             break;
         }
@@ -3344,21 +3354,17 @@ bool QOpenGLTexture::hasFeature(Feature feature)
 */
 void QOpenGLTexture::setMipBaseLevel(int baseLevel)
 {
-#if !defined(QT_OPENGL_ES_2)
-    if (!QOpenGLContext::currentContext()->isOpenGLES()) {
-        Q_D(QOpenGLTexture);
-        d->create();
-        Q_ASSERT(d->textureId);
-        Q_ASSERT(d->texFuncs);
-        Q_ASSERT(baseLevel <= d->maxLevel);
-        d->baseLevel = baseLevel;
-        d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_BASE_LEVEL, baseLevel);
+    Q_D(QOpenGLTexture);
+    d->create();
+    if (!d->features.testFlag(TextureMipMapLevel)) {
+        qWarning("QOpenGLTexture::setMipBaseLevel: requires OpenGL >= 1.2 or OpenGL ES >= 3.0");
         return;
     }
-#else
-    Q_UNUSED(baseLevel);
-#endif
-    qWarning("QOpenGLTexture: Mipmap base level is not supported");
+    Q_ASSERT(d->textureId);
+    Q_ASSERT(d->texFuncs);
+    Q_ASSERT(baseLevel <= d->maxLevel);
+    d->baseLevel = baseLevel;
+    d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_BASE_LEVEL, baseLevel);
 }
 
 /*!
@@ -3381,21 +3387,17 @@ int QOpenGLTexture::mipBaseLevel() const
 */
 void QOpenGLTexture::setMipMaxLevel(int maxLevel)
 {
-#if !defined(QT_OPENGL_ES_2)
-    if (!QOpenGLContext::currentContext()->isOpenGLES()) {
-        Q_D(QOpenGLTexture);
-        d->create();
-        Q_ASSERT(d->textureId);
-        Q_ASSERT(d->texFuncs);
-        Q_ASSERT(d->baseLevel <= maxLevel);
-        d->maxLevel = maxLevel;
-        d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_MAX_LEVEL, maxLevel);
+    Q_D(QOpenGLTexture);
+    d->create();
+    if (!d->features.testFlag(TextureMipMapLevel)) {
+        qWarning("QOpenGLTexture::setMipMaxLevel: requires OpenGL >= 1.2 or OpenGL ES >= 3.0");
         return;
     }
-#else
-    Q_UNUSED(maxLevel);
-#endif
-    qWarning("QOpenGLTexture: Mipmap max level is not supported");
+    Q_ASSERT(d->textureId);
+    Q_ASSERT(d->texFuncs);
+    Q_ASSERT(d->baseLevel <= maxLevel);
+    d->maxLevel = maxLevel;
+    d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_MAX_LEVEL, maxLevel);
 }
 
 /*!
@@ -3418,22 +3420,17 @@ int QOpenGLTexture::mipMaxLevel() const
 */
 void QOpenGLTexture::setMipLevelRange(int baseLevel, int maxLevel)
 {
-#if !defined(QT_OPENGL_ES_2)
-    if (!QOpenGLContext::currentContext()->isOpenGLES()) {
-        Q_D(QOpenGLTexture);
-        d->create();
-        Q_ASSERT(d->textureId);
-        Q_ASSERT(d->texFuncs);
-        Q_ASSERT(baseLevel <= maxLevel);
-        d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_BASE_LEVEL, baseLevel);
-        d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_MAX_LEVEL, maxLevel);
+    Q_D(QOpenGLTexture);
+    d->create();
+    if (!d->features.testFlag(TextureMipMapLevel)) {
+        qWarning("QOpenGLTexture::setMipLevelRange: requires OpenGL >= 1.2 or OpenGL ES >= 3.0");
         return;
     }
-#else
-    Q_UNUSED(baseLevel);
-    Q_UNUSED(maxLevel);
-#endif
-    qWarning("QOpenGLTexture: Mipmap level range is not supported");
+    Q_ASSERT(d->textureId);
+    Q_ASSERT(d->texFuncs);
+    Q_ASSERT(baseLevel <= maxLevel);
+    d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_BASE_LEVEL, baseLevel);
+    d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_MAX_LEVEL, maxLevel);
 }
 
 /*!
@@ -3676,7 +3673,6 @@ QOpenGLTexture::DepthStencilMode QOpenGLTexture::depthStencilMode() const
 */
 void QOpenGLTexture::setComparisonFunction(QOpenGLTexture::ComparisonFunction function)
 {
-#if !defined(QT_OPENGL_ES_2)
     Q_D(QOpenGLTexture);
     d->create();
     if (!d->features.testFlag(TextureComparisonOperators)) {
@@ -3685,10 +3681,6 @@ void QOpenGLTexture::setComparisonFunction(QOpenGLTexture::ComparisonFunction fu
     }
     d->comparisonFunction = function;
     d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_COMPARE_FUNC, function);
-#else
-    Q_UNUSED(function);
-    qWarning("QOpenGLTexture: texture comparison functions are not supported");
-#endif
 }
 
 /*!
@@ -3724,7 +3716,6 @@ QOpenGLTexture::ComparisonFunction QOpenGLTexture::comparisonFunction() const
 */
 void QOpenGLTexture::setComparisonMode(QOpenGLTexture::ComparisonMode mode)
 {
-#if !defined(QT_OPENGL_ES_2)
     Q_D(QOpenGLTexture);
     d->create();
     if (!d->features.testFlag(TextureComparisonOperators)) {
@@ -3733,10 +3724,6 @@ void QOpenGLTexture::setComparisonMode(QOpenGLTexture::ComparisonMode mode)
     }
     d->comparisonMode = mode;
     d->texFuncs->glTextureParameteri(d->textureId, d->target, d->bindingTarget, GL_TEXTURE_COMPARE_MODE, mode);
-#else
-    Q_UNUSED(mode);
-    qWarning("QOpenGLTexture: texture comparison modes are not supported");
-#endif
 }
 
 /*!