Refactored YUV test.

client/deps/glbench/src/yuv2rgb_4.glslf

+/*
+ * Copyright 2010, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * This is a semiplanar YUV to RGB conversion shader that uses separate
+ * samplers to hold Y, and UV components.
+ */
+
+uniform sampler2D ySampler;
+uniform sampler2D uvSampler; /* GL_LUMINANCE_ALPHA */
+
+#if defined (USE_UNIFORM_MATRIX)
+uniform mat4 conversion;
+#endif
+
+varying vec2 yPlane;
+varying vec2 uvPlane;
+
+void main() {
+#if defined(I915_WORKAROUND)
+  float yChannel = texture2D(ySampler, gl_TexCoord[0].xy).r;
+  vec2 uvChannel = texture2D(uvSampler, gl_TexCoord[0].zw).ra;
+#else
+  float yChannel = texture2D(ySampler, yPlane).r;
+  vec2 uvChannel = texture2D(uvSampler, uvPlane).ra;
+#endif
+  /*
+   * This does the colorspace conversion from Y'UV to RGB as a matrix
+   * multiply.  It also does the offset of the U and V channels from
+   * [0,1] to [-.5,.5] as part of the transform.
+   */
+  vec4 channels = vec4(yChannel, uvChannel, 1.0);
+
+#if !defined(USE_UNIFORM_MATRIX)
+  mat4 conversion = mat4( 1.0,    1.0,    1.0,   0.0,
+                          0.0,   -0.344,  1.772, 0.0,
+                          1.402, -0.714,  0.0,   0.0,
+                         -0.701,  0.529, -0.886, 1.0);
+#endif
+
+  gl_FragColor = conversion * channels;
+}