1 files changed, 108 insertions, 0 deletions
diff --git a/slideshow/opengl/honeycombFragmentShader.glsl b/slideshow/opengl/honeycombFragmentShader.glsl
new file mode 100644
index 000000000..e4ce8e31f
--- /dev/null
+++ b/slideshow/opengl/honeycombFragmentShader.glsl
@@ -0,0 +1,108 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#version 150
+
+in vec2 texturePosition;
+in float fuzz;
+in vec2 v_center;
+in vec3 normal;
+in vec4 shadowCoordinate;
+
+uniform sampler2D slideTexture;
+uniform sampler2D colorShadowTexture;
+uniform sampler2D depthShadowTexture;
+uniform float selectedTexture;
+uniform float time;
+uniform float hexagonSize;
+
+bool isBorder(vec2 point)
+{
+    return point.x < 0.02 || point.x > 0.98 || point.y < 0.02 || point.y > 0.98;
+}
+
+void main()
+{
+    const vec2 samplingPoints[9] = vec2[](
+        vec2(0, 0),
+        vec2(-1, -1),
+        vec2(-1, 0),
+        vec2(-1, 1),
+        vec2(0, 1),
+        vec2(1, 1),
+        vec2(1, 0),
+        vec2(1, -1),
+        vec2(0, -1)
+    );
+
+    vec4 fragment = vec4(texture(slideTexture, texturePosition).rgb, 1.0);
+    vec3 lightVector = vec3(0.0, 0.0, 1.0);
+    float light = max(dot(lightVector, normal), 0.0);
+    if (hexagonSize > 1.0) {
+        // The space in-between hexagons.
+        if (selectedTexture > 0.5)
+            fragment.a = 1.0 - time * 8 + gl_FragCoord.x / 1024.;
+        else
+            fragment.a = time * 8 - 7.3 + gl_FragCoord.x / 1024.;
+    } else {
+        // The hexagons themselves.
+
+        float startTime;
+        float actualTime;
+        if (selectedTexture > 0.5) {
+            // Leaving slide.
+            if (isBorder(v_center))
+                // If the center is “outside” of the canvas, clear it first.
+                startTime = 0.15;
+            else
+                startTime = 0.15 + fuzz * 0.4;
+            float endTime = startTime + 0.05;
+            actualTime = 1.0 - clamp((time - startTime) / (endTime - startTime), 0, 1);
+        } else {
+            // Entering slide.
+            if (isBorder(v_center))
+                // If the center is “outside” of the canvas, clear it first.
+                startTime = 0.85;
+            else
+                startTime = 0.3 + fuzz * 0.4;
+            float endTime = startTime + 0.05;
+            actualTime = clamp((time - startTime) / (endTime - startTime), 0, 1);
+            if (time < 0.8)
+                actualTime *= time / 0.8;
+        }
+
+        if (selectedTexture > 0.5) {
+            // Leaving texture needs to be transparent to see-through.
+            fragment.a = actualTime;
+        } else {
+            // Entering one though, would look weird with transparency.
+            fragment.rgb *= actualTime;
+        }
+    }
+
+    // Compute the shadow.
+    float visibility = 1.0;
+    const float epsilon = 0.0001;
+    if (selectedTexture < 0.5) {
+        float depthShadow = texture(depthShadowTexture, shadowCoordinate.xy).z;
+        float shadowRadius = (1.0 / (shadowCoordinate.z - depthShadow)) * 1000.0;
+        // Only the entering slide.
+        for (int i = 0; i < 9; ++i) {
+            vec2 coordinate = shadowCoordinate.xy + samplingPoints[i] / shadowRadius;
+            if (depthShadow < shadowCoordinate.z - epsilon) {
+                visibility -= 0.05 * texture(colorShadowTexture, coordinate).a;
+            }
+        }
+    }
+
+    vec4 black = vec4(0.0, 0.0, 0.0, fragment.a);
+    gl_FragColor = mix(black, fragment, visibility * light);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */