weston/libweston/renderer-gl/fragment.glsl
Pekka Paalanen 3f6be39f94 gl-renderer: factor out sample_input_texture()
Reading the input texture is just one part of the future color pipeline,
so separate it into a function of its own. This makes it easier to add
more steps to the pipeline, and shows the green tint is separate as
well.

Making use of early returns, reducing the if-else ladder should help
with readability. Sharing the call to yuva2rgba() likewise.

Setting yuva.w = alpha is not shared though, in case support for AYUV
format might be added in the future.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
2021-02-25 14:36:46 +02:00

148 lines
3.8 KiB
GLSL

/*
* Copyright 2012 Intel Corporation
* Copyright 2015,2019,2021 Collabora, Ltd.
* Copyright 2016 NVIDIA Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* GLSL version 1.00 ES, defined in gl-shaders.c */
/*
* Enumeration of shader variants, must match enum gl_shader_texture_variant.
*/
#define SHADER_VARIANT_RGBX 1
#define SHADER_VARIANT_RGBA 2
#define SHADER_VARIANT_Y_U_V 3
#define SHADER_VARIANT_Y_UV 4
#define SHADER_VARIANT_Y_XUXV 5
#define SHADER_VARIANT_XYUV 6
#define SHADER_VARIANT_SOLID 7
#define SHADER_VARIANT_EXTERNAL 8
#if DEF_VARIANT == SHADER_VARIANT_EXTERNAL
#extension GL_OES_EGL_image_external : require
#endif
precision mediump float;
/*
* These undeclared identifiers will be #defined by a runtime generated code
* snippet.
*/
const int c_variant = DEF_VARIANT;
const bool c_green_tint = DEF_GREEN_TINT;
vec4
yuva2rgba(vec4 yuva)
{
vec4 color_out;
float Y, su, sv;
Y = 1.16438356 * (yuva.x - 0.0625);
su = yuva.y - 0.5;
sv = yuva.z - 0.5;
color_out.r = Y + 1.59602678 * sv;
color_out.g = Y - 0.39176229 * su - 0.81296764 * sv;
color_out.b = Y + 2.01723214 * su;
color_out.rgb *= yuva.w;
color_out.a = yuva.w;
return color_out;
}
#if DEF_VARIANT == SHADER_VARIANT_EXTERNAL
uniform samplerExternalOES tex;
#else
uniform sampler2D tex;
#endif
varying vec2 v_texcoord;
uniform sampler2D tex1;
uniform sampler2D tex2;
uniform float alpha;
uniform vec4 unicolor;
vec4
sample_input_texture()
{
vec4 yuva;
/* Producing RGBA directly */
if (c_variant == SHADER_VARIANT_SOLID)
return alpha * unicolor;
if (c_variant == SHADER_VARIANT_RGBA ||
c_variant == SHADER_VARIANT_EXTERNAL) {
return alpha * texture2D(tex, v_texcoord);
}
if (c_variant == SHADER_VARIANT_RGBX)
return vec4(alpha * texture2D(tex, v_texcoord).rgb, alpha);
/* Requires conversion to RGBA */
if (c_variant == SHADER_VARIANT_Y_U_V) {
yuva.x = texture2D(tex, v_texcoord).x;
yuva.y = texture2D(tex1, v_texcoord).x;
yuva.z = texture2D(tex2, v_texcoord).x;
yuva.w = alpha;
} else if (c_variant == SHADER_VARIANT_Y_UV) {
yuva.x = texture2D(tex, v_texcoord).x;
yuva.yz = texture2D(tex1, v_texcoord).rg;
yuva.w = alpha;
} else if (c_variant == SHADER_VARIANT_Y_XUXV) {
yuva.x = texture2D(tex, v_texcoord).x;
yuva.yz = texture2D(tex1, v_texcoord).ga;
yuva.w = alpha;
} else if (c_variant == SHADER_VARIANT_XYUV) {
yuva.xyz = texture2D(tex, v_texcoord).bgr;
yuva.w = alpha;
} else {
/* Never reached, bad variant value. */
return vec4(1.0, 0.3, 1.0, 1.0);
}
return yuva2rgba(yuva);
}
void
main()
{
vec4 color;
/* Electrical (non-linear) RGBA values, pre-multiplied */
color = sample_input_texture();
if (c_green_tint)
color = vec4(0.0, 0.3, 0.0, 0.2) + color * 0.8;
gl_FragColor = color;
}