qcam: Add OpenGL shader code as Qt resource

Add OpenGL fragment and vertex shaders to convert two- and tri-planar
YUV formats to RGB. This will be used to accelerate YUV image rendering.

Signed-off-by: Show Liu <show.liu@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/qcam/assets/shader/NV_2_planes_UV_f.glsl

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * NV_2_planes_UV_f.glsl - 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;
+	yuv.y = texture2D(tex_u, textureOut).r - 0.500;
+	yuv.z = texture2D(tex_u, textureOut).g - 0.500;
+
+	rgb = yuv2rgb_bt601_mat * yuv;
+	gl_FragColor = vec4(rgb, 1.0);
+}

src/qcam/assets/shader/NV_2_planes_VU_f.glsl

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * NV_2_planes_VU_f.glsl - Fragment shader code for NV21, NV61 and NV42 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;
+	yuv.y = texture2D(tex_u, textureOut).g - 0.500;
+	yuv.z = texture2D(tex_u, textureOut).r - 0.500;
+
+	rgb = yuv2rgb_bt601_mat * yuv;
+	gl_FragColor = vec4(rgb, 1.0);
+}

src/qcam/assets/shader/NV_3_planes_f.glsl

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * NV_3_planes_UV_f.glsl - Fragment shader code for YUV420 format
+ */
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+varying vec2 textureOut;
+uniform sampler2D tex_y;
+uniform sampler2D tex_u;
+uniform sampler2D tex_v;
+
+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;
+	yuv.y = texture2D(tex_u, textureOut).r - 0.500;
+	yuv.z = texture2D(tex_v, textureOut).r - 0.500;
+
+	rgb = yuv2rgb_bt601_mat * yuv;
+	gl_FragColor = vec4(rgb, 1.0);
+}

src/qcam/assets/shader/NV_vertex_shader.glsl

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * NV_vertex_shader.glsl - Vertex shader code for NV family
+ */
+
+attribute vec4 vertexIn;
+attribute vec2 textureIn;
+varying vec2 textureOut;
+
+void main(void)
+{
+	gl_Position = vertexIn;
+	textureOut = textureIn;
+}

src/qcam/assets/shader/shaders.qrc

@@ -0,0 +1,9 @@
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource>
+<file>./NV_vertex_shader.glsl</file>
+<file>./NV_2_planes_UV_f.glsl</file>
+<file>./NV_2_planes_VU_f.glsl</file>
+<file>./NV_3_planes_f.glsl</file>
+</qresource>
+</RCC>

src/qcam/meson.build

@@ -16,6 +16,7 @@ qcam_moc_headers = files([
 
 qcam_resources = files([
     'assets/feathericons/feathericons.qrc',
+    'assets/shader/shaders.qrc'
 ])
 
 qt5 = import('qt5')