Transition: Add Push transition

Signed-off-by: Javiya Vivekkumar Dineshbhai <vivek.javiya@collabora.com>
Change-Id: I68fe10793e29d823a27f12a6bf22f4cdd3756e70

3 files changed, 110 insertions, 1 deletions

diff --git a/browser/Makefile.am b/browser/Makefile.am
index 906b0d5075..aa7004e740 100644
--- a/browser/Makefile.am
+++ b/browser/Makefile.am
@@ -422,6 +422,7 @@ COOL_JS_LST =\
 	src/slideshow/transition/BoxTransition.ts \
 	src/slideshow/transition/DiamondTransition.ts\
 	src/slideshow/transition/CheckersTransition.ts \
+	src/slideshow/transition/PushTransition.ts \
 	src/slideshow/transition/SimpleDissolveTransition.ts \
 	src/slideshow/transition/BarsTransition.ts \
 	src/slideshow/transition/CutTransition.ts \
@@ -873,6 +874,7 @@ pot:
 		src/slideshow/transition/OvalTransition.ts\
 		src/slideshow/transition/DiamondTransition.ts\
 		src/slideshow/transition/CheckersTransition.ts \
+		src/slideshow/transition/PushTransition.ts \
 		src/slideshow/transition/SimpleDissolveTransition.ts \
 		src/slideshow/transition/BarsTransition.ts \
 		src/slideshow/transition/CutTransition.ts \
diff --git a/browser/src/slideshow/PerformTransition.ts b/browser/src/slideshow/PerformTransition.ts
index 8b7e509d45..b0d88ad36c 100644
--- a/browser/src/slideshow/PerformTransition.ts
+++ b/browser/src/slideshow/PerformTransition.ts
@@ -134,7 +134,8 @@ SlideShow.PerformTransition = function (
                 image1,
                 image2,
             ).start(1);
-            break;   
+            break;
+
         case 'DISSOLVE':
             new SimpleDissolveTransition(
                 canvas,
@@ -143,6 +144,14 @@ SlideShow.PerformTransition = function (
             ).start();
             break;
 
+        case 'PUSH':
+            new PushTransition(
+                canvas,
+                image1,
+                image2,
+            ).start(1);
+            break;
+
 
         default:
             console.error('Unknown transition type');
diff --git a/browser/src/slideshow/transition/PushTransition.ts b/browser/src/slideshow/transition/PushTransition.ts
new file mode 100644
index 0000000000..5cc28d63d0
--- /dev/null
+++ b/browser/src/slideshow/transition/PushTransition.ts
@@ -0,0 +1,98 @@
+/*
+ * 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/.
+ */
+
+declare var SlideShow: any;
+
+class PushTransition extends Transition2d {
+	private direction: number = 0;
+	constructor(
+		canvas: HTMLCanvasElement,
+		image1: HTMLImageElement,
+		image2: HTMLImageElement,
+	) {
+		super(canvas, image1, image2);
+		this.prepareTransition();
+		this.animationTime = 2000;
+	}
+
+	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;
+
+                void main() {
+                    vec2 uv = v_texCoord;
+                    float progress = time;
+
+                    vec2 leavingUV = uv;
+                    vec2 enteringUV = uv;
+
+                    if (direction == 1) {
+                        // bottom to top
+                        leavingUV = uv + vec2(0.0, progress);
+                        enteringUV = uv + vec2(0.0, -1.0 + progress);
+                    } else if (direction == 2) {
+                        // left to right
+                        leavingUV = uv + vec2(-progress, 0.0);
+                        enteringUV = uv + vec2(1.0 - progress, 0.0);
+                    } else if (direction == 3) {
+                        // right to left
+                        leavingUV = uv + vec2(progress, 0.0);
+                        enteringUV = uv + vec2(-1.0 + progress, 0.0);
+                    } else if (direction == 4) {
+                        // top to bottom
+                        leavingUV = uv + vec2(0.0, -progress);
+                        enteringUV = uv + vec2(0.0, 1.0 - progress);
+                    }
+
+                    if ((direction == 1 && uv.y > 1.0 - progress) ||
+                        (direction == 2 && uv.x < progress) ||
+                        (direction == 3 && uv.x > 1.0 - progress) ||
+                        (direction == 4 && uv.y < progress)) {
+                        outColor = texture(enteringSlideTexture, enteringUV);
+                    } else {
+                        outColor = texture(leavingSlideTexture, leavingUV);
+                    }
+                }
+                `;
+	}
+}