qcam: viewfinder_gl: Merge the semi-planar UV and VU shaders

Use macros to select the U and V pattern, to avoid code duplication
between the two semi-planar shaders.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

1 files changed, 39 insertions, 0 deletions

diff --git a/src/qcam/assets/shader/YUV_2_planes.frag b/src/qcam/assets/shader/YUV_2_planes.frag
new file mode 100644
index 00000000..125f1c85
--- /dev/null
+++ b/src/qcam/assets/shader/YUV_2_planes.frag
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * YUV_2_planes.frag - Fragment shader code for NV12, NV16 and NV24 formats
+ */
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+varying vec2 textureOut;
+uniform sampler2D tex_y;
+uniform sampler2D tex_u;
+
+void main(void)
+{
+	vec3 yuv;
+	vec3 rgb;
+	mat3 yuv2rgb_bt601_mat = mat3(
+		vec3(1.164,  1.164, 1.164),
+		vec3(0.000, -0.392, 2.017),
+		vec3(1.596, -0.813, 0.000)
+	);
+
+	yuv.x = texture2D(tex_y, textureOut).r - 0.063;
+#if defined(YUV_PATTERN_UV)
+	yuv.y = texture2D(tex_u, textureOut).r - 0.500;
+	yuv.z = texture2D(tex_u, textureOut).g - 0.500;
+#elif defined(YUV_PATTERN_VU)
+	yuv.y = texture2D(tex_u, textureOut).g - 0.500;
+	yuv.z = texture2D(tex_u, textureOut).r - 0.500;
+#else
+#error Invalid pattern
+#endif
+
+	rgb = yuv2rgb_bt601_mat * yuv;
+	gl_FragColor = vec4(rgb, 1.0);
+}