slideshow: Reimplement reflections in shaders, and port Rochade and TurnAround

This removes the hack reflections were previously, where a black quad
was drawn on top of a mirror version of the first primitive only.

Change-Id: I8c0863ab30e85d0130a8d7e838f3514e9be93788

5 files changed, 171 insertions, 87 deletions

diff --git a/slideshow/Package_opengl.mk b/slideshow/Package_opengl.mk
index 82fb3b937f18..1293c05f62c4 100644
--- a/slideshow/Package_opengl.mk
+++ b/slideshow/Package_opengl.mk
@@ -15,6 +15,8 @@ $(eval $(call gb_Package_add_files,slideshow_opengl_shader,$(LIBO_ETC_FOLDER)/op
 		dissolveFragmentShader.glsl \
 		fadeBlackFragmentShader.glsl \
 		fadeFragmentShader.glsl \
+		reflectionVertexShader.glsl \
+		reflectionFragmentShader.glsl \
 		staticFragmentShader.glsl \
 		vortexFragmentShader.glsl \
 		vortexVertexShader.glsl \
diff --git a/slideshow/opengl/reflectionFragmentShader.glsl b/slideshow/opengl/reflectionFragmentShader.glsl
new file mode 100644
index 000000000000..9bf8ecb70c3d
--- /dev/null
+++ b/slideshow/opengl/reflectionFragmentShader.glsl
@@ -0,0 +1,47 @@
+/* -*- 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 130
+
+uniform sampler2D slideTexture;
+varying float v_isShadow;
+varying vec2 v_texturePosition;
+
+void main() {
+    vec4 fragment = texture2D(slideTexture, v_texturePosition);
+    if (v_isShadow > 0.5) {
+        if (v_texturePosition.y > 1.0 - 0.3)
+            gl_FragColor = mix(fragment, vec4(0.0, 0.0, 0.0, 0.0), (1.0 - v_texturePosition.y) / 0.3);
+        else
+            discard;
+    } else {
+        gl_FragColor = fragment;
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/slideshow/opengl/reflectionVertexShader.glsl b/slideshow/opengl/reflectionVertexShader.glsl
new file mode 100644
index 000000000000..b08d0cc82f59
--- /dev/null
+++ b/slideshow/opengl/reflectionVertexShader.glsl
@@ -0,0 +1,41 @@
+/* -*- 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 2008 by Sun Microsystems, Inc.
+ *
+ * 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 130
+
+varying float v_isShadow;
+varying vec2 v_texturePosition;
+
+void main( void )
+{
+    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
+    v_texturePosition = gl_MultiTexCoord0.xy;
+    v_isShadow = float(gl_VertexID >= 6);
+}
+
+/* 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 1f4cf9fdb782..dd791aed6017 100644
--- a/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx
+++ b/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx
@@ -93,53 +93,6 @@ void OGLTransitionImpl::finish()
     finishTransition();
 }
 
-static void blendSlide( double depth )
-{
-    CHECK_GL_ERROR();
-    double showHeight = -1 + depth*2;
-    GLfloat reflectionColor[] = {0, 0, 0, 0.25};
-
-    glDisable( GL_DEPTH_TEST );
-    glBegin( GL_QUADS );
-    glColor4fv( reflectionColor );
-    glVertex3f( -1, -1, 0 );
-    glColor4f( 0, 0, 0, 1 );
-    glVertex3f(-1,  showHeight, 0 );
-    glVertex3f( 1,  showHeight, 0 );
-    glColor4fv( reflectionColor );
-    glVertex3f( 1, -1, 0 );
-    glEnd();
-
-    glBegin( GL_QUADS );
-    glColor4f( 0, 0, 0, 1 );
-    glVertex3f( -1, showHeight, 0 );
-    glVertex3f( -1,  1, 0 );
-    glVertex3f(  1,  1, 0 );
-    glVertex3f(  1, showHeight, 0 );
-    glEnd();
-    glEnable( GL_DEPTH_TEST );
-    CHECK_GL_ERROR();
-}
-
-static void slideShadow( double nTime, const Primitive& primitive, double sw, double sh )
-{
-    CHECK_GL_ERROR();
-    double reflectionDepth = 0.3;
-
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-    glDisable(GL_LIGHTING);
-
-    glPushMatrix();
-    primitive.applyOperations( nTime, sw, sh );
-    blendSlide( reflectionDepth );
-    glPopMatrix();
-
-    glDisable(GL_BLEND);
-    glEnable(GL_LIGHTING);
-    CHECK_GL_ERROR();
-}
-
 void OGLTransitionImpl::prepare( double, double, double, double, double )
 {
 }
@@ -256,33 +209,8 @@ OGLTransitionImpl::displaySlide(
         double SlideWidthScale, double SlideHeightScale )
 {
     CHECK_GL_ERROR();
-    //TODO change to foreach
     glBindTexture(GL_TEXTURE_2D, glSlideTex);
     CHECK_GL_ERROR();
-
-    // display slide reflection
-    // note that depth test is turned off while blending the shadow
-    // so the slides has to be rendered in right order, see rochade as example
-    if( maSettings.mbReflectSlides ) {
-        double surfaceLevel = -0.04;
-
-        /* reflected slides */
-        glPushMatrix();
-
-        glm::mat4 matrix;
-        matrix = glm::scale(matrix, glm::vec3(1, -1, 1));
-        matrix = glm::translate(matrix, glm::vec3(0, 2 - surfaceLevel, 0));
-        glMultMatrixf(glm::value_ptr(matrix));
-
-        glCullFace(GL_FRONT);
-        display_primitives(primitives, nTime, SlideWidthScale, SlideHeightScale);
-        glCullFace(GL_BACK);
-
-        slideShadow( nTime, primitives[0], SlideWidthScale, SlideHeightScale );
-
-        glPopMatrix();
-    }
-
     display_primitives(primitives, nTime, SlideWidthScale, SlideHeightScale);
     CHECK_GL_ERROR();
 }
@@ -493,6 +421,69 @@ void ShaderTransition::impl_setTextureUniforms()
 namespace
 {
 
+class ReflectionTransition : public ShaderTransition
+{
+public:
+    ReflectionTransition(const TransitionScene& rScene, const TransitionSettings& rSettings)
+        : ShaderTransition(rScene, rSettings)
+    {}
+
+private:
+    virtual GLuint makeShader() const override;
+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;
+
+    virtual void impl_prepareTransition() override {
+        glDisable(GL_CULL_FACE);
+    }
+
+    virtual void impl_finishTransition() override {
+        glEnable(GL_CULL_FACE);
+    }
+};
+
+GLuint ReflectionTransition::makeShader() const
+{
+    return OpenGLHelper::LoadShaders( "reflectionVertexShader", "reflectionFragmentShader" );
+}
+
+void ReflectionTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,
+                                              double SlideWidthScale, double SlideHeightScale )
+{
+    CHECK_GL_ERROR();
+    applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );
+
+    sal_Int32 texture;
+    Primitives_t slide;
+    if (nTime < 0.5) {
+        texture = glLeavingSlideTex;
+        slide = getScene().getLeavingSlide();
+    } else {
+        texture = glEnteringSlideTex;
+        slide = getScene().getEnteringSlide();
+    }
+
+    displaySlide( nTime, texture, slide, SlideWidthScale, SlideHeightScale );
+    CHECK_GL_ERROR();
+}
+
+std::shared_ptr<OGLTransitionImpl>
+makeReflectionTransition(
+        const Primitives_t& rLeavingSlidePrimitives,
+        const Primitives_t& rEnteringSlidePrimitives,
+        const Operations_t& rOverallOperations,
+        const TransitionSettings& rSettings = TransitionSettings())
+{
+    return std::make_shared<ReflectionTransition>(
+            TransitionScene(rLeavingSlidePrimitives, rEnteringSlidePrimitives, rOverallOperations, SceneObjects_t()),
+            rSettings)
+        ;
+}
+
+}
+
+namespace
+{
+
 class SimpleTransition : public ShaderTransition
 {
 public:
@@ -639,25 +630,30 @@ std::shared_ptr<OGLTransitionImpl> makeFallLeaving()
 std::shared_ptr<OGLTransitionImpl> makeTurnAround()
 {
     Primitive Slide;
-
     TransitionSettings aSettings;
-    aSettings.mbReflectSlides = true;
 
     Slide.pushTriangle(glm::vec2(0,0),glm::vec2(1,0),glm::vec2(0,1));
     Slide.pushTriangle(glm::vec2(1,0),glm::vec2(0,1),glm::vec2(1,1));
     Primitives_t aLeavingPrimitives;
     aLeavingPrimitives.push_back(Slide);
 
+    Slide.Operations.push_back(makeSScale(glm::vec3(1, -1, 1), glm::vec3(0, -1.02, 0), false, -1, 0));
+    aLeavingPrimitives.push_back(Slide);
+
+    Slide.Operations.clear();
     Slide.Operations.push_back(makeRotateAndScaleDepthByWidth(glm::vec3(0,1,0),glm::vec3(0,0,0),-180,false,0.0,1.0));
     Primitives_t aEnteringPrimitives;
     aEnteringPrimitives.push_back(Slide);
 
+    Slide.Operations.push_back(makeSScale(glm::vec3(1, -1, 1), glm::vec3(0, -1.02, 0), false, -1, 0));
+    aEnteringPrimitives.push_back(Slide);
+
     Operations_t aOperations;
     aOperations.push_back(makeSTranslate(glm::vec3(0, 0, -1.5),true, 0, 0.5));
     aOperations.push_back(makeSTranslate(glm::vec3(0, 0, 1.5), true, 0.5, 1));
     aOperations.push_back(makeRotateAndScaleDepthByWidth(glm::vec3(0, 1, 0),glm::vec3(0, 0, 0), -180, true, 0.0, 1.0));
 
-    return makeSimpleTransition(aLeavingPrimitives, aEnteringPrimitives, aOperations, aSettings);
+    return makeReflectionTransition(aLeavingPrimitives, aEnteringPrimitives, aOperations, aSettings);
 }
 
 std::shared_ptr<OGLTransitionImpl> makeTurnDown()
@@ -755,15 +751,15 @@ std::shared_ptr<OGLTransitionImpl> makeIris()
 namespace
 {
 
-class RochadeTransition : public SimpleTransition
+class RochadeTransition : public ReflectionTransition
 {
 public:
     RochadeTransition(const TransitionScene& rScene, const TransitionSettings& rSettings)
-        : SimpleTransition(rScene, rSettings)
+        : ReflectionTransition(rScene, rSettings)
     {}
 
 private:
-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;
+    virtual void displaySlides_(double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale) override;
 };
 
 void RochadeTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )
@@ -798,9 +794,7 @@ makeRochadeTransition(
 std::shared_ptr<OGLTransitionImpl> makeRochade()
 {
     Primitive Slide;
-
     TransitionSettings aSettings;
-    aSettings.mbReflectSlides = true;
 
     double w, h;
 
@@ -815,6 +809,9 @@ std::shared_ptr<OGLTransitionImpl> makeRochade()
     Primitives_t aLeavingSlide;
     aLeavingSlide.push_back(Slide);
 
+    Slide.Operations.push_back(makeSScale(glm::vec3(1, -1, 1), glm::vec3(0, -1.02, 0), false, -1, 0));
+    aLeavingSlide.push_back(Slide);
+
     Slide.Operations.clear();
     Slide.Operations.push_back(makeSEllipseTranslate(w, h, 0.75, 0.25, true, 0, 1));
     Slide.Operations.push_back(makeSTranslate(glm::vec3(0, 0, -h), false, -1, 0));
@@ -823,6 +820,9 @@ std::shared_ptr<OGLTransitionImpl> makeRochade()
     Primitives_t aEnteringSlide;
     aEnteringSlide.push_back(Slide);
 
+    Slide.Operations.push_back(makeSScale(glm::vec3(1, -1, 1), glm::vec3(0, -1.02, 0), false, -1, 0));
+    aEnteringSlide.push_back(Slide);
+
     return makeRochadeTransition(aLeavingSlide, aEnteringSlide, aSettings);
 }
 
diff --git a/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.hxx b/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.hxx
index a9f8b627dd07..4238f8ea8b91 100644
--- a/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.hxx
+++ b/slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.hxx
@@ -51,8 +51,7 @@ struct TransitionSettings
     TransitionSettings() :
         mbUseMipMapLeaving( true ),
         mbUseMipMapEntering( true ),
-        mnRequiredGLVersion( 1.0 ),
-        mbReflectSlides( false )
+        mnRequiredGLVersion( 1.0 )
     {
     }
 
@@ -64,11 +63,6 @@ struct TransitionSettings
     /** which GL version does the transition require
      */
     float mnRequiredGLVersion;
-
-    /** Whether to reflect slides, the reflection happens on flat surface beneath the slides.
-     ** Now it only works with slides which keep their rectangular shape together.
-     */
-    bool mbReflectSlides;
 };
 
 typedef std::vector<Primitive> Primitives_t;