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CLK/Outputs/OpenGL/ScanTargetGLSLFragments.cpp

533 lines
17 KiB
C++

//
// ScanTargetVertexArrayAttributs.cpp
// Clock Signal
//
// Created by Thomas Harte on 11/11/2018.
// Copyright © 2018 Thomas Harte. All rights reserved.
//
#include "ScanTarget.hpp"
#include <cmath>
using namespace Outputs::Display::OpenGL;
void Outputs::Display::OpenGL::ScanTarget::set_uniforms(ShaderType type, Shader &target) {
// Slightly over-amping rowHeight here is a cheap way to make sure that lines
// converge even allowing for the fact that they may not be spaced by exactly
// the expected distance. Cf. the stencil-powered logic for making sure all
// pixels are painted only exactly once per field.
target.set_uniform("rowHeight", GLfloat(1.05f / modals_.expected_vertical_lines));
target.set_uniform("scale", GLfloat(modals_.output_scale.x), GLfloat(modals_.output_scale.y));
target.set_uniform("phaseOffset", GLfloat(modals_.input_data_tweaks.phase_linked_luminance_offset));
}
void ScanTarget::enable_vertex_attributes(ShaderType type, Shader &target) {
#define rt_offset_of(field, source) (reinterpret_cast<uint8_t *>(&source.field) - reinterpret_cast<uint8_t *>(&source))
// test_scan and test_line are here so that the byte offsets that need to be
// calculated inside a loop can be done so validly; offsetof requires constant arguments.
Scan test_scan;
Line test_line;
switch(type) {
case ShaderType::Composition:
for(int c = 0; c < 2; ++c) {
const std::string prefix = c ? "end" : "start";
target.enable_vertex_attribute_with_pointer(
prefix + "DataX",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Scan),
reinterpret_cast<void *>(rt_offset_of(scan.end_points[c].data_offset, test_scan)),
1);
target.enable_vertex_attribute_with_pointer(
prefix + "Clock",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Scan),
reinterpret_cast<void *>(rt_offset_of(scan.end_points[c].cycles_since_end_of_horizontal_retrace, test_scan)),
1);
}
target.enable_vertex_attribute_with_pointer(
"dataY",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Scan),
reinterpret_cast<void *>(offsetof(Scan, data_y)),
1);
target.enable_vertex_attribute_with_pointer(
"lineY",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Scan),
reinterpret_cast<void *>(offsetof(Scan, line)),
1);
break;
case ShaderType::Conversion:
for(int c = 0; c < 2; ++c) {
const std::string prefix = c ? "end" : "start";
target.enable_vertex_attribute_with_pointer(
prefix + "Point",
2, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Line),
reinterpret_cast<void *>(rt_offset_of(end_points[c].x, test_line)),
1);
target.enable_vertex_attribute_with_pointer(
prefix + "Clock",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Line),
reinterpret_cast<void *>(rt_offset_of(end_points[c].cycles_since_end_of_horizontal_retrace, test_line)),
1);
target.enable_vertex_attribute_with_pointer(
prefix + "CompositeAngle",
1, GL_SHORT, GL_FALSE,
sizeof(Line),
reinterpret_cast<void *>(rt_offset_of(end_points[c].composite_angle, test_line)),
1);
}
target.enable_vertex_attribute_with_pointer(
"lineY",
1, GL_UNSIGNED_SHORT, GL_FALSE,
sizeof(Line),
reinterpret_cast<void *>(offsetof(Line, line)),
1);
target.enable_vertex_attribute_with_pointer(
"lineCompositeAmplitude",
1, GL_UNSIGNED_BYTE, GL_FALSE,
sizeof(Line),
reinterpret_cast<void *>(offsetof(Line, composite_amplitude)),
1);
break;
}
#undef rt_offset_of
}
std::unique_ptr<Shader> ScanTarget::composition_shader() const {
const std::string vertex_shader =
"#version 150\n"
"in float startDataX;"
"in float startClock;"
"in float endDataX;"
"in float endClock;"
"in float dataY;"
"in float lineY;"
"out vec2 textureCoordinate;"
"uniform usampler2D textureName;"
"void main(void) {"
"float lateral = float(gl_VertexID & 1);"
"float longitudinal = float((gl_VertexID & 2) >> 1);"
"textureCoordinate = vec2(mix(startDataX, endDataX, lateral), dataY + 0.5) / textureSize(textureName, 0);"
"vec2 eyePosition = vec2(mix(startClock, endClock, lateral), lineY + longitudinal) / vec2(2048.0, 2048.0);"
"gl_Position = vec4(eyePosition*2.0 - vec2(1.0), 0.0, 1.0);"
"}";
std::string fragment_shader =
"#version 150\n"
"out vec4 fragColour;"
"in vec2 textureCoordinate;"
"uniform usampler2D textureName;"
"void main(void) {";
switch(modals_.input_data_type) {
case InputDataType::Luminance1:
fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0).rrrr;";
break;
case InputDataType::Luminance8:
fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0).rrrr / vec4(255.0);";
break;
case InputDataType::PhaseLinkedLuminance8:
case InputDataType::Luminance8Phase8:
case InputDataType::Red8Green8Blue8:
fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0) / vec4(255.0);";
break;
case InputDataType::Red1Green1Blue1:
fragment_shader += "fragColour = vec4(textureLod(textureName, textureCoordinate, 0).rrr & uvec3(4u, 2u, 1u), 1.0);";
break;
case InputDataType::Red2Green2Blue2:
fragment_shader +=
"uint textureValue = textureLod(textureName, textureCoordinate, 0).r;"
"fragColour = vec4(float((textureValue >> 4) & 3u), float((textureValue >> 2) & 3u), float(textureValue & 3u), 3.0) / 3.0;";
break;
case InputDataType::Red4Green4Blue4:
fragment_shader +=
"uvec2 textureValue = textureLod(textureName, textureCoordinate, 0).rg;"
"fragColour = vec4(float(textureValue.r) / 15.0, float(textureValue.g & 240u) / 240.0, float(textureValue.g & 15u) / 15.0, 1.0);";
break;
}
return std::unique_ptr<Shader>(new Shader(
vertex_shader,
fragment_shader + "}",
{
{"startDataX", 0},
{"startClock", 1},
{"endDataX", 2},
{"endClock", 3},
{"dataY", 4},
{"lineY", 5},
}
));
}
std::unique_ptr<Shader> ScanTarget::conversion_shader() const {
// Compose a vertex shader. If the display type is RGB, generate just the proper
// geometry position, plus a solitary textureCoordinate.
//
// If the display type is anything other than RGB, also produce composite
// angle and 1/composite amplitude as outputs.
//
// If the display type is composite colour, generate four textureCoordinates,
// spanning a range of -135, -45, +45, +135 degrees.
//
// If the display type is S-Video, generate three textureCoordinates, at
// -45, 0, +45.
std::string vertex_shader =
"#version 150\n"
"uniform vec2 scale;"
"uniform float rowHeight;"
"in vec2 startPoint;"
"in vec2 endPoint;"
"in float startClock;"
"in float startCompositeAngle;"
"in float endClock;"
"in float endCompositeAngle;"
"in float lineY;"
"in float lineCompositeAmplitude;"
"uniform sampler2D textureName;"
"uniform vec2 origin;"
"uniform vec2 size;";
std::string fragment_shader =
"#version 150\n"
"uniform sampler2D textureName;"
"out vec4 fragColour;";
if(modals_.display_type != DisplayType::RGB) {
vertex_shader +=
"out float compositeAngle;"
"out float compositeAmplitude;"
"out float oneOverCompositeAmplitude;"
"uniform vec4 textureCoordinateOffsets;"
"uniform float angleOffsets[4];"
;
fragment_shader +=
"in float compositeAngle;"
"in float compositeAmplitude;"
"in float oneOverCompositeAmplitude;";
}
switch(modals_.display_type){
case DisplayType::RGB:
case DisplayType::CompositeMonochrome:
vertex_shader += "out vec2 textureCoordinate;";
fragment_shader += "in vec2 textureCoordinate;";
break;
case DisplayType::CompositeColour:
case DisplayType::SVideo:
vertex_shader +=
"out vec2 textureCoordinates[4];"
"out vec4 angles;";
fragment_shader +=
"in vec2 textureCoordinates[4];"
"in vec4 angles;";
break;
}
// Add the code to generate a proper output position; this applies to all display types.
vertex_shader +=
"void main(void) {"
"float lateral = float(gl_VertexID & 1);"
"float longitudinal = float((gl_VertexID & 2) >> 1);"
"vec2 centrePoint = mix(startPoint, vec2(endPoint.x, startPoint.y), lateral) / scale;"
"vec2 height = normalize(vec2(endPoint.x, startPoint.y) - startPoint).yx * (longitudinal - 0.5) * rowHeight;"
"vec2 eyePosition = vec2(-1.0, 1.0) + vec2(2.0, -2.0) * (((centrePoint + height) - origin) / size);"
"gl_Position = vec4(eyePosition, 0.0, 1.0);";
// For everything other than RGB, calculate the two composite outputs.
if(modals_.display_type != DisplayType::RGB) {
vertex_shader +=
"compositeAngle = (mix(startCompositeAngle, endCompositeAngle, lateral) / 32.0) * 3.141592654;"
"compositeAmplitude = lineCompositeAmplitude / 255.0;"
"oneOverCompositeAmplitude = mix(0.0, 255.0 / lineCompositeAmplitude, step(0.01, lineCompositeAmplitude));";
}
// For RGB and monochrome composite, generate the single texture coordinate; otherwise generate either three
// or four depending on the type of decoding to apply.
switch(modals_.display_type){
case DisplayType::RGB:
case DisplayType::CompositeMonochrome:
vertex_shader +=
"textureCoordinate = vec2(mix(startClock, endClock, lateral), lineY + 0.5) / textureSize(textureName, 0);";
break;
case DisplayType::CompositeColour:
case DisplayType::SVideo:
vertex_shader +=
"float centreClock = mix(startClock, endClock, lateral);"
"textureCoordinates[0] = vec2(centreClock + textureCoordinateOffsets[0], lineY + 0.5) / textureSize(textureName, 0);"
"textureCoordinates[1] = vec2(centreClock + textureCoordinateOffsets[1], lineY + 0.5) / textureSize(textureName, 0);"
"textureCoordinates[2] = vec2(centreClock + textureCoordinateOffsets[2], lineY + 0.5) / textureSize(textureName, 0);"
"textureCoordinates[3] = vec2(centreClock + textureCoordinateOffsets[3], lineY + 0.5) / textureSize(textureName, 0);"
"angles = vec4("
"compositeAngle - 2.356194490192345,"
"compositeAngle - 0.785398163397448,"
"compositeAngle + 0.785398163397448,"
"compositeAngle + 2.356194490192345"
");";
break;
}
vertex_shader += "}";
// Compose a fragment shader.
//
// For an RGB display ... [TODO]
if(modals_.display_type != DisplayType::RGB) {
fragment_shader +=
"uniform mat3 lumaChromaToRGB;"
"uniform mat3 rgbToLumaChroma;";
}
if(modals_.display_type == DisplayType::SVideo) {
fragment_shader +=
"vec2 svideo_sample(vec2 coordinate, float angle) {";
switch(modals_.input_data_type) {
case InputDataType::Luminance1:
case InputDataType::Luminance8:
// Easy, just copy across.
fragment_shader += "return vec2(texture(textureName, coordinate).r, 0.0);";
break;
case InputDataType::PhaseLinkedLuminance8:
fragment_shader +=
"uint iPhase = uint((angle * 2.0 / 3.141592654) ) & 3u;" // + phaseOffset*4.0
"return vec2(texture(textureName, coordinate)[iPhase], 0.0);";
break;
case InputDataType::Luminance8Phase8:
fragment_shader +=
"vec2 yc = texture(textureName, coordinate).rg;"
"float phaseOffset = 3.141592654 * 2.0 * 2.0 * yc.y;"
"float rawChroma = step(yc.y, 0.75) * cos(angle + phaseOffset);"
"return vec2(yc.x, rawChroma);";
break;
case InputDataType::Red1Green1Blue1:
case InputDataType::Red2Green2Blue2:
case InputDataType::Red4Green4Blue4:
case InputDataType::Red8Green8Blue8:
fragment_shader +=
"vec3 colour = rgbToLumaChroma * texture(textureName, coordinate).rgb;"
"vec2 quadrature = vec2(cos(angle), sin(angle));"
"return vec2(colour.r, dot(quadrature, colour.gb));";
break;
}
fragment_shader += "}";
}
if(modals_.display_type == DisplayType::CompositeMonochrome || modals_.display_type == DisplayType::CompositeColour) {
fragment_shader +=
"float composite_sample(vec2 coordinate, float angle) {";
switch(modals_.input_data_type) {
case InputDataType::Luminance1:
case InputDataType::Luminance8:
// Easy, just copy across.
fragment_shader += "return texture(textureName, coordinate).r;";
break;
case InputDataType::PhaseLinkedLuminance8:
fragment_shader +=
"uint iPhase = uint((angle * 2.0 / 3.141592654) ) & 3u;" // + phaseOffset*4.0
"return texture(textureName, coordinate)[iPhase];";
break;
case InputDataType::Luminance8Phase8:
fragment_shader +=
"vec2 yc = texture(textureName, coordinate).rg;"
"float phaseOffset = 3.141592654 * 2.0 * 2.0 * yc.y;"
"float rawChroma = step(yc.y, 0.75) * cos(angle + phaseOffset);"
"return mix(yc.x, rawChroma, compositeAmplitude);";
break;
case InputDataType::Red1Green1Blue1:
case InputDataType::Red2Green2Blue2:
case InputDataType::Red4Green4Blue4:
case InputDataType::Red8Green8Blue8:
fragment_shader +=
"vec3 colour = rgbToLumaChroma * texture(textureName, coordinate).rgb;"
"vec2 quadrature = vec2(cos(angle), sin(angle));"
"return mix(colour.r, dot(quadrature, colour.gb), compositeAmplitude);";
break;
}
fragment_shader += "}";
}
fragment_shader +=
"void main(void) {"
"vec3 fragColour3;";
switch(modals_.display_type) {
case DisplayType::RGB:
fragment_shader += "fragColour3 = texture(textureName, textureCoordinate).rgb;";
break;
case DisplayType::SVideo:
fragment_shader +=
// Sample four times over, at proper angle offsets.
"vec2 samples[4] = vec2[4]("
"svideo_sample(textureCoordinates[0], angles[0]),"
"svideo_sample(textureCoordinates[1], angles[1]),"
"svideo_sample(textureCoordinates[2], angles[2]),"
"svideo_sample(textureCoordinates[3], angles[3])"
");"
"vec4 chrominances = vec4("
"samples[0].y,"
"samples[1].y,"
"samples[2].y,"
"samples[3].y"
");"
// Split and average chrominance.
"vec2 channels = vec2("
"dot(cos(angles), chrominances),"
"dot(sin(angles), chrominances)"
") * vec2(0.25);"
// Apply a colour space conversion to get RGB.
"fragColour3 = lumaChromaToRGB * vec3(samples[1].x, channels);";
break;
case DisplayType::CompositeColour:
fragment_shader +=
// Sample four times over, at proper angle offsets.
"vec4 samples = vec4("
"composite_sample(textureCoordinates[0], angles[0]),"
"composite_sample(textureCoordinates[1], angles[1]),"
"composite_sample(textureCoordinates[2], angles[2]),"
"composite_sample(textureCoordinates[3], angles[3])"
");"
// Compute a luminance for use if there's no colour information, now, before
// modifying samples.
"float mono_luminance = dot(samples.yz, vec2(0.5));"
// Take the average to calculate luminance, then subtract that from all four samples to
// give chrominance.
"float luminance = dot(samples, vec4(0.25));"
"samples -= vec4(luminance);"
"luminance /= (1.0 - compositeAmplitude);"
// Split and average chrominance.
"vec2 channels = vec2("
"dot(cos(angles), samples),"
"dot(sin(angles), samples)"
") * vec2(0.125 * oneOverCompositeAmplitude);"
// Apply a colour space conversion to get RGB.
"fragColour3 = mix("
"lumaChromaToRGB * vec3(luminance, channels),"
"vec3(mono_luminance),"
"step(oneOverCompositeAmplitude, 0.01)"
");";
break;
case DisplayType::CompositeMonochrome:
fragment_shader += "fragColour3 = vec3(composite_sample(textureCoordinate, compositeAngle));";
break;
}
// Apply a brightness adjustment if requested.
if(fabs(modals_.brightness - 1.0f) > 0.05f) {
fragment_shader += "fragColour3 = fragColour3 * " + std::to_string(modals_.brightness) + ";";
}
// Apply a gamma correction if required.
if(fabs(output_gamma_ - modals_.intended_gamma) > 0.05f) {
const float gamma_ratio = output_gamma_ / modals_.intended_gamma;
fragment_shader += "fragColour3 = pow(fragColour3, vec3(" + std::to_string(gamma_ratio) + "));";
}
fragment_shader +=
"fragColour = vec4(fragColour3, 0.64);"
"}";
const auto shader = new Shader(
vertex_shader,
fragment_shader,
{
{"startPoint", 0},
{"endPoint", 1},
{"startClock", 2},
{"endClock", 3},
{"lineY", 4},
{"lineCompositeAmplitude", 5},
{"startCompositeAngle", 6},
{"endCompositeAngle", 7},
}
);
// If this isn't an RGB or composite colour shader, set the proper colour space.
if(modals_.display_type != DisplayType::RGB) {
float clocks_per_angle = float(modals_.cycles_per_line) * float(modals_.colour_cycle_denominator) / float(modals_.colour_cycle_numerator);
shader->set_uniform("textureCoordinateOffsets",
-0.375f * clocks_per_angle,
-0.125f * clocks_per_angle,
+0.125f * clocks_per_angle,
+0.375f * clocks_per_angle);
switch(modals_.composite_colour_space) {
case ColourSpace::YIQ: {
const GLfloat rgbToYIQ[] = {0.299f, 0.596f, 0.211f, 0.587f, -0.274f, -0.523f, 0.114f, -0.322f, 0.312f};
const GLfloat yiqToRGB[] = {1.0f, 1.0f, 1.0f, 0.956f, -0.272f, -1.106f, 0.621f, -0.647f, 1.703f};
shader->set_uniform_matrix("lumaChromaToRGB", 3, false, yiqToRGB);
shader->set_uniform_matrix("rgbToLumaChroma", 3, false, rgbToYIQ);
} break;
case ColourSpace::YUV: {
const GLfloat rgbToYUV[] = {0.299f, -0.14713f, 0.615f, 0.587f, -0.28886f, -0.51499f, 0.114f, 0.436f, -0.10001f};
const GLfloat yuvToRGB[] = {1.0f, 1.0f, 1.0f, 0.0f, -0.39465f, 2.03211f, 1.13983f, -0.58060f, 0.0f};
shader->set_uniform_matrix("lumaChromaToRGB", 3, false, yuvToRGB);
shader->set_uniform_matrix("rgbToLumaChroma", 3, false, rgbToYUV);
} break;
}
}
return std::unique_ptr<Shader>(shader);
}