slideshow: Reimplement both Fade transitions in shaders

Change-Id: I94187b9316a206578bb738411053afe070703f09

4 files changed, 108 insertions, 62 deletions

diff --git a/slideshow/Package_opengl.mk b/slideshow/Package_opengl.mk
index dc03ff655fb0..82fb3b937f18 100644
--- a/slideshow/Package_opengl.mk
+++ b/slideshow/Package_opengl.mk
@@ -13,6 +13,8 @@ $(eval $(call gb_Package_add_files,slideshow_opengl_shader,$(LIBO_ETC_FOLDER)/op
 		basicVertexShader.glsl \
 		basicFragmentShader.glsl \
 		dissolveFragmentShader.glsl \
+		fadeBlackFragmentShader.glsl \
+		fadeFragmentShader.glsl \
 		staticFragmentShader.glsl \
 		vortexFragmentShader.glsl \
 		vortexVertexShader.glsl \
diff --git a/slideshow/opengl/fadeBlackFragmentShader.glsl b/slideshow/opengl/fadeBlackFragmentShader.glsl
new file mode 100644
index 000000000000..7f80cc55adcb
--- /dev/null
+++ b/slideshow/opengl/fadeBlackFragmentShader.glsl
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*************************************************************************
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Copyright 2015 by Collabora, Ltd.
+ *
+ * OpenOffice.org - a multi-platform office productivity suite
+ *
+ * This file is part of OpenOffice.org.
+ *
+ * OpenOffice.org is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3
+ * only, as published by the Free Software Foundation.
+ *
+ * OpenOffice.org is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3 for more details
+ * (a copy is included in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * version 3 along with OpenOffice.org.  If not, see
+ * <http://www.openoffice.org/license.html>
+ * for a copy of the LGPLv3 License.
+ *
+ ************************************************************************/
+
+#version 120
+
+uniform sampler2D leavingSlideTexture;
+uniform sampler2D enteringSlideTexture;
+uniform float time;
+varying vec2 v_texturePosition;
+
+void main() {
+    vec4 black = vec4(0.0, 0.0, 0.0, 1.0);
+    vec4 texel;
+    float amount;
+    if (time < 0.5) {
+        texel = texture2D(leavingSlideTexture, v_texturePosition);
+        amount = time * 2;
+    } else {
+        texel = texture2D(enteringSlideTexture, v_texturePosition);
+        amount = (1.0 - time) * 2;
+    }
+    gl_FragColor = mix(texel, black, amount);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/slideshow/opengl/fadeFragmentShader.glsl b/slideshow/opengl/fadeFragmentShader.glsl
new file mode 100644
index 000000000000..aab848e3c917
--- /dev/null
+++ b/slideshow/opengl/fadeFragmentShader.glsl
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*************************************************************************
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Copyright 2015 by Collabora, Ltd.
+ *
+ * OpenOffice.org - a multi-platform office productivity suite
+ *
+ * This file is part of OpenOffice.org.
+ *
+ * OpenOffice.org is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 3
+ * only, as published by the Free Software Foundation.
+ *
+ * OpenOffice.org is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3 for more details
+ * (a copy is included in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * version 3 along with OpenOffice.org.  If not, see
+ * <http://www.openoffice.org/license.html>
+ * for a copy of the LGPLv3 License.
+ *
+ ************************************************************************/
+
+#version 120
+
+uniform sampler2D leavingSlideTexture;
+uniform sampler2D enteringSlideTexture;
+uniform float time;
+varying vec2 v_texturePosition;
+
+void main() {
+    vec4 leavingFragment = texture2D(leavingSlideTexture, v_texturePosition);
+    vec4 enteringFragment = texture2D(enteringSlideTexture, v_texturePosition);
+    gl_FragColor = mix(leavingFragment, enteringFragment, time);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx b/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx
index 6575da2ad948..1f4cf9fdb782 100644
--- a/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx
+++ b/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx
@@ -1367,51 +1367,22 @@ std::shared_ptr<OGLTransitionImpl> makeVenetianBlinds( bool vertical, int parts
 namespace
 {
 
-class FadeSmoothlyTransition : public SimpleTransition
+class FadeSmoothlyTransition : public ShaderTransition
 {
 public:
     FadeSmoothlyTransition(const TransitionScene& rScene, const TransitionSettings& rSettings)
-        : SimpleTransition(rScene, rSettings)
+        : ShaderTransition(rScene, rSettings)
     {}
 
 private:
-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;
+    virtual GLuint makeShader() const override;
+    virtual void impl_prepareTransition() override {}
+    virtual void impl_finishTransition() override {}
 };
 
-void FadeSmoothlyTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )
+GLuint FadeSmoothlyTransition::makeShader() const
 {
-    CHECK_GL_ERROR();
-    applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );
-
-    CHECK_GL_ERROR();
-    glDisable(GL_DEPTH_TEST);
-
-    CHECK_GL_ERROR();
-    displaySlide( nTime, glLeavingSlideTex, getScene().getLeavingSlide(), SlideWidthScale, SlideHeightScale );
-    CHECK_GL_ERROR();
-
-    CHECK_GL_ERROR();
-    glDisable(GL_LIGHTING);
-    CHECK_GL_ERROR();
-    glEnable(GL_BLEND);
-    CHECK_GL_ERROR();
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-    CHECK_GL_ERROR();
-    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-    CHECK_GL_ERROR();
-    glColor4f( 1, 1, 1, nTime );
-    CHECK_GL_ERROR();
-    displaySlide( nTime, glEnteringSlideTex, getScene().getEnteringSlide(), SlideWidthScale, SlideHeightScale );
-    CHECK_GL_ERROR();
-    glDisable(GL_BLEND);
-    CHECK_GL_ERROR();
-    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
-    CHECK_GL_ERROR();
-    glEnable(GL_LIGHTING);
-    CHECK_GL_ERROR();
-
-    glEnable(GL_DEPTH_TEST);
-    CHECK_GL_ERROR();
+    return OpenGLHelper::LoadShaders( "basicVertexShader", "fadeFragmentShader" );
 }
 
 std::shared_ptr<OGLTransitionImpl>
@@ -1448,41 +1419,22 @@ std::shared_ptr<OGLTransitionImpl> makeFadeSmoothly()
 namespace
 {
 
-class FadeThroughBlackTransition : public SimpleTransition
+class FadeThroughBlackTransition : public ShaderTransition
 {
 public:
     FadeThroughBlackTransition(const TransitionScene& rScene, const TransitionSettings& rSettings)
-        : SimpleTransition(rScene, rSettings)
+        : ShaderTransition(rScene, rSettings)
     {}
 
 private:
-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;
+    virtual GLuint makeShader() const override;
+    virtual void impl_prepareTransition() override {}
+    virtual void impl_finishTransition() override {}
 };
 
-void FadeThroughBlackTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )
+GLuint FadeThroughBlackTransition::makeShader() const
 {
-    CHECK_GL_ERROR();
-    applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );
-
-    glDisable(GL_DEPTH_TEST);
-
-    glDisable(GL_LIGHTING);
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-    if( nTime < 0.5 ) {
-        glColor4f( 1, 1, 1, 1 - nTime*2 );
-        displaySlide( nTime, glLeavingSlideTex, getScene().getLeavingSlide(), SlideWidthScale, SlideHeightScale );
-    } else {
-        glColor4f( 1, 1, 1, (nTime - 0.5)*2 );
-        displaySlide( nTime, glEnteringSlideTex, getScene().getEnteringSlide(), SlideWidthScale, SlideHeightScale );
-    }
-    glDisable(GL_BLEND);
-    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
-    glEnable(GL_LIGHTING);
-
-    glEnable(GL_DEPTH_TEST);
-    CHECK_GL_ERROR();
+    return OpenGLHelper::LoadShaders( "basicVertexShader", "fadeBlackFragmentShader" );
 }
 
 std::shared_ptr<OGLTransitionImpl>