implement PowerPoint 'flash' slide transition (API CHANGE)

It's like 'fade', but using white instead of black. It's a separate
type in the pptx file (although I actually cannot find it
in the spec OOXML, but PowerPoint 2013 generates it).
The API change in XTransitionFactory should be fine, I doubt
there's anything external using it.

Change-Id: I3479840f265ed8227b3b8301ecff56a63d57f493
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93668
Tested-by: Luboš Luňák <l.lunak@collabora.com>
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

5 files changed, 31 insertions, 15 deletions

diff --git a/slideshow/opengl/fadeBlackFragmentShader.glsl b/slideshow/opengl/fadeBlackFragmentShader.glsl
index d45a736c8065..3d618a3b4b91 100644
--- a/slideshow/opengl/fadeBlackFragmentShader.glsl
+++ b/slideshow/opengl/fadeBlackFragmentShader.glsl
@@ -15,7 +15,11 @@ uniform float time;
 varying vec2 v_texturePosition;
 
 void main() {
-    vec4 black = vec4(0.0, 0.0, 0.0, 1.0);
+#ifdef use_white
+    vec4 color = vec4(1.0, 1.0, 1.0, 1.0);
+#else
+    vec4 color = vec4(0.0, 0.0, 0.0, 1.0);
+#endif
     vec4 texel;
     float amount;
     if (time < 0.5) {
@@ -25,7 +29,7 @@ void main() {
         texel = texture2D(enteringSlideTexture, v_texturePosition);
         amount = (1.0 - time) * 2;
     }
-    gl_FragColor = mix(texel, black, amount);
+    gl_FragColor = mix(texel, color, amount);
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/slideshow/source/engine/opengl/TransitionImpl.cxx b/slideshow/source/engine/opengl/TransitionImpl.cxx
index d1926ab854f9..98d6778fd197 100644
--- a/slideshow/source/engine/opengl/TransitionImpl.cxx
+++ b/slideshow/source/engine/opengl/TransitionImpl.cxx
@@ -1351,37 +1351,40 @@ std::shared_ptr<OGLTransitionImpl> makeFadeSmoothly()
 namespace
 {
 
-class FadeThroughBlackTransition : public OGLTransitionImpl
+class FadeThroughColorTransition : public OGLTransitionImpl
 {
 public:
-    FadeThroughBlackTransition(const TransitionScene& rScene, const TransitionSettings& rSettings)
-        : OGLTransitionImpl(rScene, rSettings)
+    FadeThroughColorTransition(const TransitionScene& rScene, const TransitionSettings& rSettings, bool white)
+        : OGLTransitionImpl(rScene, rSettings), useWhite( white )
     {}
 
 private:
     virtual GLuint makeShader() const override;
+    bool useWhite;
 };
 
-GLuint FadeThroughBlackTransition::makeShader() const
+GLuint FadeThroughColorTransition::makeShader() const
 {
-    return OpenGLHelper::LoadShaders( "basicVertexShader", "fadeBlackFragmentShader" );
+    return OpenGLHelper::LoadShaders( "basicVertexShader", "fadeBlackFragmentShader",
+        useWhite ? "#define use_white" : "", "" );
 }
 
 std::shared_ptr<OGLTransitionImpl>
-makeFadeThroughBlackTransition(
+makeFadeThroughColorTransition(
         const Primitives_t& rLeavingSlidePrimitives,
         const Primitives_t& rEnteringSlidePrimitives,
-        const TransitionSettings& rSettings)
+        const TransitionSettings& rSettings,
+        bool white)
 {
-    return std::make_shared<FadeThroughBlackTransition>(
+    return std::make_shared<FadeThroughColorTransition>(
             TransitionScene(rLeavingSlidePrimitives, rEnteringSlidePrimitives),
-            rSettings)
+            rSettings, white)
         ;
 }
 
 }
 
-std::shared_ptr<OGLTransitionImpl> makeFadeThroughBlack()
+std::shared_ptr<OGLTransitionImpl> makeFadeThroughColor( bool white )
 {
     Primitive Slide;
 
@@ -1395,7 +1398,7 @@ std::shared_ptr<OGLTransitionImpl> makeFadeThroughBlack()
     TransitionSettings aSettings;
     aSettings.mbUseMipMapLeaving = aSettings.mbUseMipMapEntering = false;
 
-    return makeFadeThroughBlackTransition(aLeavingSlide, aEnteringSlide, aSettings);
+    return makeFadeThroughColorTransition(aLeavingSlide, aEnteringSlide, aSettings, white);
 }
 
 namespace
diff --git a/slideshow/source/engine/opengl/TransitionImpl.hxx b/slideshow/source/engine/opengl/TransitionImpl.hxx
index 2831685cd3a7..ca1d36366a6c 100644
--- a/slideshow/source/engine/opengl/TransitionImpl.hxx
+++ b/slideshow/source/engine/opengl/TransitionImpl.hxx
@@ -271,7 +271,8 @@ std::shared_ptr<OGLTransitionImpl> makeNewsflash();
 
 std::shared_ptr<OGLTransitionImpl> makeDiamond();
 std::shared_ptr<OGLTransitionImpl> makeFadeSmoothly();
-std::shared_ptr<OGLTransitionImpl> makeFadeThroughBlack();
+// fade through black or white
+std::shared_ptr<OGLTransitionImpl> makeFadeThroughColor( bool white = false );
 
 class SceneObject
 {
diff --git a/slideshow/source/engine/opengl/TransitionerImpl.cxx b/slideshow/source/engine/opengl/TransitionerImpl.cxx
index 7403cad87425..c60be299752a 100644
--- a/slideshow/source/engine/opengl/TransitionerImpl.cxx
+++ b/slideshow/source/engine/opengl/TransitionerImpl.cxx
@@ -1214,6 +1214,7 @@ public:
     virtual uno::Reference< presentation::XTransition > SAL_CALL createTransition(
         sal_Int16                                             transitionType,
         sal_Int16                                             transitionSubType,
+        sal_Int32                                             transitionFadeColor,
         const uno::Reference< presentation::XSlideShowView >& view,
         const uno::Reference< rendering::XBitmap >&           leavingBitmap,
         const uno::Reference< rendering::XBitmap >&           enteringBitmap ) override
@@ -1288,7 +1289,7 @@ public:
         } else if( transitionType == animations::TransitionType::FADE && transitionSubType == animations::TransitionSubType::CROSSFADE ) {
             pTransition = makeFadeSmoothly();
         } else if( transitionType == animations::TransitionType::FADE && transitionSubType == animations::TransitionSubType::FADEOVERCOLOR ) {
-            pTransition = makeFadeThroughBlack();
+            pTransition = makeFadeThroughColor( transitionFadeColor == 0xffffff );
         } else if( transitionType == animations::TransitionType::IRISWIPE && transitionSubType == animations::TransitionSubType::DIAMOND ) {
             pTransition = makeDiamond();
         } else if( transitionType == animations::TransitionType::ZOOM && transitionSubType == animations::TransitionSubType::ROTATEIN ) {
diff --git a/slideshow/source/engine/transitions/slidetransitionfactory.cxx b/slideshow/source/engine/transitions/slidetransitionfactory.cxx
index ec67e434cb7c..66faf10e09b3 100644
--- a/slideshow/source/engine/transitions/slidetransitionfactory.cxx
+++ b/slideshow/source/engine/transitions/slidetransitionfactory.cxx
@@ -108,6 +108,7 @@ public:
     */
     PluginSlideChange( sal_Int16                                nTransitionType,
                        sal_Int16                                nTransitionSubType,
+                       const RGBColor&                          rTransitionFadeColor,
                        std::optional<SlideSharedPtr> const&   leavingSlide_,
                        const SlideSharedPtr&                    pEnteringSlide,
                        const UnoViewContainer&                  rViewContainer,
@@ -126,6 +127,7 @@ public:
         mbSuccess( false ),
         mnTransitionType( nTransitionType ),
         mnTransitionSubType( nTransitionSubType ),
+        mnTransitionFadeColor( rTransitionFadeColor ),
         mxFactory( xFactory )
     {
         // create one transition per view
@@ -150,6 +152,7 @@ public:
         uno::Reference<presentation::XTransition> rTransition = mxFactory->createTransition(
             mnTransitionType,
             mnTransitionSubType,
+            RGBAColor2UnoColor( mnTransitionFadeColor.getIntegerColor()),
             rView->getUnoView(),
             getLeavingBitmap(ViewEntry(rView))->getXBitmap(),
             getEnteringBitmap(ViewEntry(rView))->getXBitmap() );
@@ -247,6 +250,7 @@ private:
 
     sal_Int16 mnTransitionType;
     sal_Int16 mnTransitionSubType;
+    RGBColor mnTransitionFadeColor;
 
     uno::Reference<presentation::XTransitionFactory> mxFactory;
 };
@@ -844,6 +848,7 @@ NumberAnimationSharedPtr createSlideWipeTransition(
 NumberAnimationSharedPtr createPluginTransition(
     sal_Int16                                nTransitionType,
     sal_Int16                                nTransitionSubType,
+    const RGBColor&                          rTransitionFadeColor,
     std::optional<SlideSharedPtr> const&   pLeavingSlide,
     const SlideSharedPtr&                    pEnteringSlide,
     const UnoViewContainer&                  rViewContainer,
@@ -857,6 +862,7 @@ NumberAnimationSharedPtr createPluginTransition(
         std::make_shared<PluginSlideChange>(
             nTransitionType,
             nTransitionSubType,
+            rTransitionFadeColor,
             pLeavingSlide,
             pEnteringSlide,
             rViewContainer,
@@ -909,6 +915,7 @@ NumberAnimationSharedPtr TransitionFactory::createSlideTransition(
             createPluginTransition(
                 nTransitionType,
                 nTransitionSubType,
+                rTransitionFadeColor,
                 std::make_optional(pLeavingSlide),
                 pEnteringSlide,
                 rViewContainer,