weston/libweston/renderer-gl/fragment.glsl
Pekka Paalanen 044379f66a gl-renderer: consolidate linpow sampling GLSL
This is pure refactoring.

Ease readability by reducing code duplication between pre and post curve
linpow handling.

While at it, define symbols for the counts. This patch converts only
linpow. Powlin are converted in follow-up.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
2024-04-18 14:56:53 +00:00

447 lines
12 KiB
GLSL

/*
* Copyright 2012 Intel Corporation
* Copyright 2015,2019,2021 Collabora, Ltd.
* Copyright 2016 NVIDIA Corporation
* Copyright 2021 Advanced Micro Devices, Inc.
*
* 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 */
/* For annotating shader compile-time constant arguments */
#define compile_const const
/*
* 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
/* enum gl_shader_color_curve */
#define SHADER_COLOR_CURVE_IDENTITY 0
#define SHADER_COLOR_CURVE_LUT_3x1D 1
#define SHADER_COLOR_CURVE_LINPOW 2
#define SHADER_COLOR_CURVE_POWLIN 3
/* enum gl_shader_color_mapping */
#define SHADER_COLOR_MAPPING_IDENTITY 0
#define SHADER_COLOR_MAPPING_3DLUT 1
#define SHADER_COLOR_MAPPING_MATRIX 2
#if DEF_VARIANT == SHADER_VARIANT_EXTERNAL
#extension GL_OES_EGL_image_external : require
#endif
#if DEF_COLOR_MAPPING == SHADER_COLOR_MAPPING_3DLUT
#extension GL_OES_texture_3D : require
#endif
#ifdef GL_FRAGMENT_PRECISION_HIGH
#define HIGHPRECISION highp
#else
#define HIGHPRECISION mediump
#endif
precision HIGHPRECISION float;
/*
* These undeclared identifiers will be #defined by a runtime generated code
* snippet.
*/
compile_const int c_variant = DEF_VARIANT;
compile_const bool c_input_is_premult = DEF_INPUT_IS_PREMULT;
compile_const bool c_green_tint = DEF_GREEN_TINT;
compile_const int c_color_pre_curve = DEF_COLOR_PRE_CURVE;
compile_const int c_color_mapping = DEF_COLOR_MAPPING;
compile_const int c_color_post_curve = DEF_COLOR_POST_CURVE;
compile_const bool c_need_color_pipeline =
c_color_pre_curve != SHADER_COLOR_CURVE_IDENTITY ||
c_color_mapping != SHADER_COLOR_MAPPING_IDENTITY ||
c_color_post_curve != SHADER_COLOR_CURVE_IDENTITY;
vec4
yuva2rgba(vec4 yuva)
{
vec4 color_out;
float Y, su, sv;
/* ITU-R BT.601 & BT.709 quantization (limited range) */
/* Y = 255/219 * (x - 16/256) */
Y = 1.16438356 * (yuva.x - 0.0625);
/* Remove offset 128/256, but the 255/224 multiplier comes later */
su = yuva.y - 0.5;
sv = yuva.z - 0.5;
/*
* ITU-R BT.601 encoding coefficients (inverse), with the
* 255/224 limited range multiplier already included in the
* factors for su (Cb) and sv (Cr).
*/
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.a = yuva.w;
return color_out;
}
#if DEF_VARIANT == SHADER_VARIANT_EXTERNAL
uniform samplerExternalOES tex;
#else
uniform sampler2D tex;
#endif
varying HIGHPRECISION vec2 v_texcoord;
uniform sampler2D tex1;
uniform sampler2D tex2;
uniform float view_alpha;
uniform vec4 unicolor;
#define MAX_CURVE_PARAMS 10
#define MAX_CURVESET_PARAMS (MAX_CURVE_PARAMS * 3)
uniform HIGHPRECISION sampler2D color_pre_curve_lut_2d;
uniform HIGHPRECISION vec2 color_pre_curve_lut_scale_offset;
uniform HIGHPRECISION float color_pre_curve_params[MAX_CURVESET_PARAMS];
uniform bool color_pre_curve_clamped_input;
uniform HIGHPRECISION sampler2D color_post_curve_lut_2d;
uniform HIGHPRECISION vec2 color_post_curve_lut_scale_offset;
uniform HIGHPRECISION float color_post_curve_params[MAX_CURVESET_PARAMS];
uniform bool color_post_curve_clamped_input;
#if DEF_COLOR_MAPPING == SHADER_COLOR_MAPPING_3DLUT
uniform HIGHPRECISION sampler3D color_mapping_lut_3d;
uniform HIGHPRECISION vec2 color_mapping_lut_scale_offset;
#endif
uniform HIGHPRECISION mat3 color_mapping_matrix;
vec4
sample_input_texture()
{
vec4 yuva = vec4(0.0, 0.0, 0.0, 1.0);
/* Producing RGBA directly */
if (c_variant == SHADER_VARIANT_SOLID)
return unicolor;
if (c_variant == SHADER_VARIANT_RGBA ||
c_variant == SHADER_VARIANT_EXTERNAL) {
return texture2D(tex, v_texcoord);
}
if (c_variant == SHADER_VARIANT_RGBX)
return vec4(texture2D(tex, v_texcoord).rgb, 1.0);
/* 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;
} else if (c_variant == SHADER_VARIANT_Y_UV) {
yuva.x = texture2D(tex, v_texcoord).x;
yuva.yz = texture2D(tex1, v_texcoord).rg;
} else if (c_variant == SHADER_VARIANT_Y_XUXV) {
yuva.x = texture2D(tex, v_texcoord).x;
yuva.yz = texture2D(tex1, v_texcoord).ga;
} else if (c_variant == SHADER_VARIANT_XYUV) {
yuva.xyz = texture2D(tex, v_texcoord).bgr;
} else {
/* Never reached, bad variant value. */
return vec4(1.0, 0.3, 1.0, 1.0);
}
return yuva2rgba(yuva);
}
/*
* Sample a 1D LUT which is a single row of a 2D texture. The 2D texture has
* four rows so that the centers of texels have precise y-coordinates.
*
* Texture coordinates go from 0.0 to 1.0 corresponding to texture edges.
* When we do LUT look-ups with linear filtering, the correct range to sample
* from is not from edge to edge, but center of first texel to center of last
* texel. This follows because with LUTs, you have the exact end points given,
* you never extrapolate but only interpolate.
* The scale and offset are precomputed to achieve this mapping.
*/
float
sample_lut_1d(HIGHPRECISION sampler2D lut, vec2 scale_offset,
float x, compile_const int row)
{
float tx = x * scale_offset.s + scale_offset.t;
float ty = (float(row) + 0.5) / 4.0;
return texture2D(lut, vec2(tx, ty)).x;
}
vec3
sample_lut_3x1d(HIGHPRECISION sampler2D lut, vec2 scale_offset, vec3 color)
{
return vec3(sample_lut_1d(lut, scale_offset, color.r, 0),
sample_lut_1d(lut, scale_offset, color.g, 1),
sample_lut_1d(lut, scale_offset, color.b, 2));
}
vec3
lut_texcoord(vec3 pos, vec2 scale_offset)
{
return pos * scale_offset.s + scale_offset.t;
}
float
linpow(float x, float g, float a, float b, float c, float d)
{
/* See WESTON_COLOR_CURVE_TYPE_LINPOW for details about LINPOW. */
if (x >= d)
return pow((a * x) + b, g);
return c * x;
}
float
powlin(float x, float g, float a, float b, float c, float d)
{
/* See WESTON_COLOR_CURVE_TYPE_POWLIN for details about POWLIN. */
if (x >= d)
return a * pow(x, g) + b;
return c * x;
}
float
sample_linpow(float params[MAX_CURVESET_PARAMS], bool must_clamp,
float x, compile_const int color_channel)
{
float g, a, b, c, d;
/*
* For each color channel we have MAX_CURVE_PARAMS parameters.
* The parameters for the three curves are stored in RGB order.
*/
g = params[0 + color_channel * MAX_CURVE_PARAMS];
a = params[1 + color_channel * MAX_CURVE_PARAMS];
b = params[2 + color_channel * MAX_CURVE_PARAMS];
c = params[3 + color_channel * MAX_CURVE_PARAMS];
d = params[4 + color_channel * MAX_CURVE_PARAMS];
if (must_clamp)
x = clamp(x, 0.0, 1.0);
/* We use mirroring for negative input values. */
if (x < 0.0)
return -linpow(-x, g, a, b, c, d);
return linpow(x, g, a, b, c, d);
}
vec3
sample_linpow_vec3(float params[MAX_CURVESET_PARAMS], bool must_clamp,
vec3 color)
{
return vec3(sample_linpow(params, must_clamp, color.r, 0),
sample_linpow(params, must_clamp, color.g, 1),
sample_linpow(params, must_clamp, color.b, 2));
}
float
sample_color_pre_curve_powlin(float x, compile_const int color_channel)
{
float g, a, b, c, d;
/* For each color channel we have 10 parameters. The params are
* linearized in an array of size 30, in RGB order. */
g = color_pre_curve_params[0 + (color_channel * 10)];
a = color_pre_curve_params[1 + (color_channel * 10)];
b = color_pre_curve_params[2 + (color_channel * 10)];
c = color_pre_curve_params[3 + (color_channel * 10)];
d = color_pre_curve_params[4 + (color_channel * 10)];
if (color_pre_curve_clamped_input)
x = clamp(x, 0.0, 1.0);
/* We use mirroring for negative input values. */
if (x < 0.0)
return -powlin(-x, g, a, b, c, d);
return powlin(x, g, a, b, c, d);
}
float
sample_color_post_curve_powlin(float x, compile_const int color_channel)
{
float g, a, b, c, d;
/* For each color channel we have 10 parameters. The params are
* linearized in an array of size 30, in RGB order. */
g = color_post_curve_params[0 + (color_channel * 10)];
a = color_post_curve_params[1 + (color_channel * 10)];
b = color_post_curve_params[2 + (color_channel * 10)];
c = color_post_curve_params[3 + (color_channel * 10)];
d = color_post_curve_params[4 + (color_channel * 10)];
if (color_post_curve_clamped_input)
x = clamp(x, 0.0, 1.0);
/* We use mirroring for negative input values. */
if (x < 0.0)
return -powlin(-x, g, a, b, c, d);
return powlin(x, g, a, b, c, d);
}
vec3
color_pre_curve(vec3 color)
{
vec3 ret;
if (c_color_pre_curve == SHADER_COLOR_CURVE_IDENTITY) {
return color;
} else if (c_color_pre_curve == SHADER_COLOR_CURVE_LUT_3x1D) {
return sample_lut_3x1d(color_pre_curve_lut_2d,
color_pre_curve_lut_scale_offset,
color);
} else if (c_color_pre_curve == SHADER_COLOR_CURVE_LINPOW) {
return sample_linpow_vec3(color_pre_curve_params,
color_pre_curve_clamped_input,
color);
} else if (c_color_pre_curve == SHADER_COLOR_CURVE_POWLIN) {
ret.r = sample_color_pre_curve_powlin(color.r, 0);
ret.g = sample_color_pre_curve_powlin(color.g, 1);
ret.b = sample_color_pre_curve_powlin(color.b, 2);
return ret;
} else {
/* Never reached, bad c_color_pre_curve. */
return vec3(1.0, 0.3, 1.0);
}
}
vec3
sample_color_mapping_lut_3d(vec3 color)
{
vec3 pos, ret = vec3(0.0, 0.0, 0.0);
#if DEF_COLOR_MAPPING == SHADER_COLOR_MAPPING_3DLUT
pos = lut_texcoord(color, color_mapping_lut_scale_offset);
ret = texture3D(color_mapping_lut_3d, pos).rgb;
#endif
return ret;
}
vec3
color_mapping(vec3 color)
{
if (c_color_mapping == SHADER_COLOR_MAPPING_IDENTITY)
return color;
else if (c_color_mapping == SHADER_COLOR_MAPPING_3DLUT)
return sample_color_mapping_lut_3d(color);
else if (c_color_mapping == SHADER_COLOR_MAPPING_MATRIX)
return color_mapping_matrix * color.rgb;
else /* Never reached, bad c_color_mapping. */
return vec3(1.0, 0.3, 1.0);
}
vec3
color_post_curve(vec3 color)
{
vec3 ret;
if (c_color_post_curve == SHADER_COLOR_CURVE_IDENTITY) {
return color;
} else if (c_color_post_curve == SHADER_COLOR_CURVE_LUT_3x1D) {
return sample_lut_3x1d(color_post_curve_lut_2d,
color_post_curve_lut_scale_offset,
color);
} else if (c_color_post_curve == SHADER_COLOR_CURVE_LINPOW) {
return sample_linpow_vec3(color_post_curve_params,
color_post_curve_clamped_input,
color);
} else if (c_color_post_curve == SHADER_COLOR_CURVE_POWLIN) {
ret.r = sample_color_post_curve_powlin(color.r, 0);
ret.g = sample_color_post_curve_powlin(color.g, 1);
ret.b = sample_color_post_curve_powlin(color.b, 2);
return ret;
} else {
/* Never reached, bad c_color_post_curve. */
return vec3(1.0, 0.3, 1.0);
}
}
vec4
color_pipeline(vec4 color)
{
/* Ensure straight alpha */
if (c_input_is_premult) {
if (color.a == 0.0)
color.rgb = vec3(0, 0, 0);
else
color.rgb *= 1.0 / color.a;
}
color.rgb = color_pre_curve(color.rgb);
color.rgb = color_mapping(color.rgb);
color.rgb = color_post_curve(color.rgb);
return color;
}
void
main()
{
vec4 color;
/* Electrical (non-linear) RGBA values, may be premult or not */
color = sample_input_texture();
if (c_need_color_pipeline)
color = color_pipeline(color); /* Produces straight alpha */
/* Ensure pre-multiplied for blending */
if (!c_input_is_premult || c_need_color_pipeline)
color.rgb *= color.a;
color *= view_alpha;
if (c_green_tint)
color = vec4(0.0, 0.3, 0.0, 0.2) + color * 0.8;
gl_FragColor = color;
}