Android: Add helper class for generating OpenGL shaders

This CL adds a helper class GlShaderBuilder to build an instances of
RendererCommon.GlDrawer that can accept multiple input sources
(OES, RGB, or YUV) using a generic fragment shader as input.

Bug: webrtc:9355
Change-Id: I14a0a280d2b6f838984f7b60897cc0c58e2a948a
Reviewed-on: https://webrtc-review.googlesource.com/80940
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23622}

sdk/android/tests/src/org/webrtc/GlGenericDrawerTest.java

@@ -0,0 +1,158 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+package org.webrtc;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.webrtc.GlShader;
+
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class GlGenericDrawerTest {
+  // Simplest possible valid generic fragment shader.
+  private static final String FRAGMENT_SHADER = "void main() {\n"
+      + "  gl_FragColor = sample(tc);\n"
+      + "}\n";
+  private static final int TEXTURE_ID = 3;
+  private static final float[] TEX_MATRIX =
+      new float[] {1, 2, 3, 4, -1, -2, -3, -4, 0, 0, 1, 0, 0, 0, 0, 1};
+  private static final int FRAME_WIDTH = 640;
+  private static final int FRAME_HEIGHT = 480;
+  private static final int VIEWPORT_X = 3;
+  private static final int VIEWPORT_Y = 5;
+  private static final int VIEWPORT_WIDTH = 500;
+  private static final int VIEWPORT_HEIGHT = 500;
+
+  // Replace OpenGLES GlShader dependency with a mock.
+  private class GlGenericDrawerForTest extends GlGenericDrawer {
+    public GlGenericDrawerForTest(String genericFragmentSource, ShaderCallbacks shaderCallbacks) {
+      super(genericFragmentSource, shaderCallbacks);
+    }
+
+    @Override
+    GlShader createShader(ShaderType shaderType) {
+      return mockedShader;
+    }
+  }
+
+  private GlShader mockedShader;
+  private GlGenericDrawer glGenericDrawer;
+  private GlGenericDrawer.ShaderCallbacks mockedCallbacks;
+
+  @Before
+  public void setUp() {
+    mockedShader = mock(GlShader.class);
+    mockedCallbacks = mock(GlGenericDrawer.ShaderCallbacks.class);
+    glGenericDrawer = new GlGenericDrawerForTest(FRAGMENT_SHADER, mockedCallbacks);
+  }
+
+  @After
+  public void tearDown() {
+    verifyNoMoreInteractions(mockedCallbacks);
+  }
+
+  @Test
+  public void testOesFragmentShader() {
+    final String expectedOesFragmentShader = "#extension GL_OES_EGL_image_external : require\n"
+        + "precision mediump float;\n"
+        + "varying vec2 tc;\n"
+        + "uniform samplerExternalOES tex;\n"
+        + "void main() {\n"
+        + "  gl_FragColor = texture2D(tex, tc);\n"
+        + "}\n";
+    final String oesFragmentShader =
+        GlGenericDrawer.createFragmentShaderString(FRAGMENT_SHADER, GlGenericDrawer.ShaderType.OES);
+    assertEquals(expectedOesFragmentShader, oesFragmentShader);
+  }
+
+  @Test
+  public void testRgbFragmentShader() {
+    final String expectedRgbFragmentShader = "precision mediump float;\n"
+        + "varying vec2 tc;\n"
+        + "uniform sampler2D tex;\n"
+        + "void main() {\n"
+        + "  gl_FragColor = texture2D(tex, tc);\n"
+        + "}\n";
+    final String rgbFragmentShader =
+        GlGenericDrawer.createFragmentShaderString(FRAGMENT_SHADER, GlGenericDrawer.ShaderType.RGB);
+    assertEquals(expectedRgbFragmentShader, rgbFragmentShader);
+  }
+
+  @Test
+  public void testYuvFragmentShader() {
+    final String expectedYuvFragmentShader = "precision mediump float;\n"
+        + "varying vec2 tc;\n"
+        + "uniform sampler2D y_tex;\n"
+        + "uniform sampler2D u_tex;\n"
+        + "uniform sampler2D v_tex;\n"
+        + "vec4 sample(vec2 p) {\n"
+        + "  float y = texture2D(y_tex, p).r;\n"
+        + "  float u = texture2D(u_tex, p).r - 0.5;\n"
+        + "  float v = texture2D(v_tex, p).r - 0.5;\n"
+        + "  return vec4(y + 1.403 * v, y - 0.344 * u - 0.714 * v, y + 1.77 * u, 1);\n"
+        + "}\n"
+        + "void main() {\n"
+        + "  gl_FragColor = sample(tc);\n"
+        + "}\n";
+    final String yuvFragmentShader =
+        GlGenericDrawer.createFragmentShaderString(FRAGMENT_SHADER, GlGenericDrawer.ShaderType.YUV);
+    assertEquals(expectedYuvFragmentShader, yuvFragmentShader);
+  }
+
+  @Test
+  public void testShaderCallbacksOneRgbFrame() {
+    glGenericDrawer.drawRgb(TEXTURE_ID, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_X,
+        VIEWPORT_Y, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+
+    verify(mockedCallbacks).onNewShader(mockedShader);
+    verify(mockedCallbacks)
+        .onPrepareShader(
+            mockedShader, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+  }
+
+  @Test
+  public void testShaderCallbacksTwoRgbFrames() {
+    glGenericDrawer.drawRgb(TEXTURE_ID, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_X,
+        VIEWPORT_Y, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+    glGenericDrawer.drawRgb(TEXTURE_ID, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_X,
+        VIEWPORT_Y, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+
+    // Expect only one shader to be created, but two frames to be drawn.
+    verify(mockedCallbacks, times(1)).onNewShader(mockedShader);
+    verify(mockedCallbacks, times(2))
+        .onPrepareShader(
+            mockedShader, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+  }
+
+  @Test
+  public void testShaderCallbacksChangingShaderType() {
+    glGenericDrawer.drawRgb(TEXTURE_ID, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_X,
+        VIEWPORT_Y, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+    glGenericDrawer.drawOes(TEXTURE_ID, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_X,
+        VIEWPORT_Y, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+
+    // Expect two shaders to be created, and two frames to be drawn.
+    verify(mockedCallbacks, times(2)).onNewShader(mockedShader);
+    verify(mockedCallbacks, times(2))
+        .onPrepareShader(
+            mockedShader, TEX_MATRIX, FRAME_WIDTH, FRAME_HEIGHT, VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
+  }
+}