transition: Add Bars transition

Signed-off-by: Javiya Vivekkumar Dineshbhai <vivek.javiya@collabora.com>
Change-Id: Iaade3d8ed5ca577c2527ce69bbe2c73f025db5f2

3 files changed, 98 insertions, 0 deletions

diff --git a/browser/Makefile.am b/browser/Makefile.am
index 20eefe5d1d..3699fcb1b5 100644
--- a/browser/Makefile.am
+++ b/browser/Makefile.am
@@ -414,6 +414,7 @@ COOL_JS_LST =\
 	src/slideshow/Transition2d.ts \
 	src/slideshow/PerformTransition.ts \
 	src/slideshow/transition/FadeTransition.ts \
+	src/slideshow/transition/BarsTransition.ts \
 	src/slideshow/transition/WheelTransition.ts \
 	src/slideshow/transition/UncoverTransition.ts \
 	src/slideshow/transition/WipeTransition.ts \
@@ -853,6 +854,7 @@ pot:
 		src/slideshow/Transition2d.ts \
 		src/slideshow/PerformTransition.ts \
 		src/slideshow/transition/FadeTransition.ts \
+		src/slideshow/transition/BarsTransition.ts \
 		src/slideshow/transition/WheelTransition.ts \
 		src/slideshow/transition/UncoverTransition.ts \
 		src/core/Socket.js \
diff --git a/browser/src/slideshow/PerformTransition.ts b/browser/src/slideshow/PerformTransition.ts
index 090e07f6bf..8d7a8e6396 100644
--- a/browser/src/slideshow/PerformTransition.ts
+++ b/browser/src/slideshow/PerformTransition.ts
@@ -47,6 +47,14 @@ SlideShow.PerformTransition = function (
                 image2,
             ).start(2);
             break;
+        
+        case 'BARS':
+            new BarsTransition(
+                canvas,
+                image1,
+                image2,
+            ).start(1);
+            break;
         default:
             console.error('Unknown transition type');
             break;
diff --git a/browser/src/slideshow/transition/BarsTransition.ts b/browser/src/slideshow/transition/BarsTransition.ts
new file mode 100644
index 0000000000..3e941f936d
--- /dev/null
+++ b/browser/src/slideshow/transition/BarsTransition.ts
@@ -0,0 +1,88 @@
+/*
+ * Copyright the Collabora Online contributors.
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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/.
+ */
+
+class BarsTransition extends Transition2d {
+	private direction: number = 0;
+	constructor(
+		canvas: HTMLCanvasElement,
+		image1: HTMLImageElement,
+		image2: HTMLImageElement,
+	) {
+		super(canvas, image1, image2);
+		this.prepareTransition();
+		this.animationTime = 1500;
+	}
+
+	public renderUniformValue(): void {
+		this.gl.uniform1i(
+			this.gl.getUniformLocation(this.program, 'direction'),
+			this.direction,
+		);
+	}
+
+	public start(direction: number): void {
+		this.direction = direction;
+		this.startTransition();
+	}
+
+	public getVertexShader(): string {
+		return `#version 300 es
+				in vec4 a_position;
+				in vec2 a_texCoord;
+				out vec2 v_texCoord;
+
+				void main() {
+					gl_Position = a_position;
+					v_texCoord = a_texCoord;
+				}
+				`;
+	}
+
+	public getFragmentShader(): string {
+		return `#version 300 es
+                precision mediump float;
+
+                uniform sampler2D leavingSlideTexture;
+                uniform sampler2D enteringSlideTexture;
+                uniform float time;
+                uniform int direction;
+
+                in vec2 v_texCoord;
+                out vec4 outColor;
+
+                float random(vec2 co) {
+                    return fract(sin(dot(co.xy, vec2(12.9898, 78.233))) * 43758.5453);
+                }
+
+                void main() {
+                    vec2 uv = v_texCoord;
+                    float progress = time;
+
+                    float numBars = 70.0; 
+                    float randValue;
+
+                    if (direction == 1) {
+                        // Vertical bars
+                        randValue = random(vec2(floor(uv.x * numBars), 0.0));
+                    } else {
+                        // Horizontal bars
+                        randValue = random(vec2(floor(uv.y * numBars), 0.0));
+                    }
+
+                    bool showEntering = (randValue < progress);
+
+                    vec4 color1 = texture(leavingSlideTexture, uv);
+                    vec4 color2 = texture(enteringSlideTexture, uv);
+
+                    outColor = mix(color1, color2, float(showEntering));
+                }
+                `;
+	}
+}