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Makes first reintroduction of colour composite decoding.

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This commit is contained in:
Thomas Harte 2018-11-24 22:30:39 -05:00
parent 6c92853461
commit cf49603a9e
3 changed files with 44 additions and 13 deletions
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2
Outputs/OpenGL/ScanTarget.cpp
View File

@ -102,7 +102,7 @@ ScanTarget::~ScanTarget() {
}
void ScanTarget::set_modals(Modals modals) {
modals.display_type = DisplayType::CompositeMonochrome;
modals.display_type = DisplayType::CompositeColour;
modals_ = modals;

1
Outputs/OpenGL/ScanTarget.hpp
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@ -179,6 +179,7 @@ class ScanTarget: public Outputs::Display::ScanTarget {
static std::unique_ptr<Shader> input_shader(InputDataType input_data_type, DisplayType display_type);
static std::unique_ptr<Shader> composite_to_svideo_shader(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width);
static std::unique_ptr<Shader> svideo_to_rgb_shader(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width);
static std::vector<float> coefficients_for_filter(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width, float multiple_of_colour_clock);
struct PipelineStage {
PipelineStage(Shader *shader, GLenum texture_unit) :

54
Outputs/OpenGL/ScanTargetGLSLFragments.cpp
View File

@ -101,14 +101,14 @@ std::string ScanTarget::glsl_default_vertex_shader(ShaderType type) {
result +=
"out float compositeAngle;"
"out float compositeAmplitudeOut;"
"out float oneOverCompositeAmplitude;"
"void main(void) {"
"float lateral = float(gl_VertexID & 1);"
"float longitudinal = float((gl_VertexID & 2) >> 1);"
"compositeAngle = (mix(startCompositeAngle, endCompositeAngle, lateral) / 32.0) * 3.141592654;"
"compositeAmplitudeOut = compositeAmplitude / 255.0;";
"oneOverCompositeAmplitude = mix(0.0, 255.0 / compositeAmplitude, step(0.01, compositeAmplitude));";
if(type == ShaderType::InputScan) {
result +=
@ -234,7 +234,7 @@ std::unique_ptr<Shader> ScanTarget::input_shader(InputDataType input_data_type,
"out vec3 fragColour;"
"in vec2 textureCoordinate;"
"in float compositeAngle;"
"in float compositeAmplitudeOut;"
"in float oneOverCompositeAmplitude;"
"uniform mat3 lumaChromaToRGB;"
"uniform mat3 rgbToLumaChroma;"
@ -325,7 +325,7 @@ std::unique_ptr<Shader> ScanTarget::input_shader(InputDataType input_data_type,
(display_type == DisplayType::CompositeMonochrome || display_type == DisplayType::CompositeColour) &&
computed_display_type != DisplayType::CompositeMonochrome
) {
fragment_shader += "fragColour = vec3(mix(fragColour.r, 2.0*(fragColour.g - 0.5), compositeAmplitudeOut));";
fragment_shader += "fragColour = vec3(mix(fragColour.r, 2.0*(fragColour.g - 0.5), 1.0 / oneOverCompositeAmplitude));";
}
return std::unique_ptr<Shader>(new Shader(
@ -335,6 +335,12 @@ std::unique_ptr<Shader> ScanTarget::input_shader(InputDataType input_data_type,
));
}
std::vector<float> ScanTarget::coefficients_for_filter(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width, float multiple_of_colour_clock) {
const float cycles_per_expanded_line = (float(colour_cycle_numerator) / float(colour_cycle_denominator)) / (float(processing_width) / float(LineBufferWidth));
const SignalProcessing::FIRFilter filter(11, float(LineBufferWidth), 0.0f, cycles_per_expanded_line * multiple_of_colour_clock);
return filter.get_coefficients();
}
std::unique_ptr<Shader> ScanTarget::svideo_to_rgb_shader(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width) {
/*
Composite to S-Video conversion is achieved by filtering the input signal to obtain luminance, and then subtracting that
@ -343,10 +349,7 @@ std::unique_ptr<Shader> ScanTarget::svideo_to_rgb_shader(int colour_cycle_numera
(Colour cycle numerator)/(Colour cycle denominator) gives the number of colour cycles in (processing_width / LineBufferWidth),
there'll be at least four samples per colour clock and in practice at most just a shade more than 9.
*/
const float cycles_per_expanded_line = (float(colour_cycle_numerator) / float(colour_cycle_denominator)) / (float(processing_width) / float(LineBufferWidth));
const SignalProcessing::FIRFilter filter(11, float(LineBufferWidth), 0.0f, cycles_per_expanded_line * 0.5f);
auto coefficients = filter.get_coefficients();
auto coefficients = coefficients_for_filter(colour_cycle_numerator, colour_cycle_denominator, processing_width, 0.5f);
auto shader = std::unique_ptr<Shader>(new Shader(
glsl_globals(ShaderType::ProcessedScan) + glsl_default_vertex_shader(ShaderType::ProcessedScan),
"#version 150\n"
@ -396,8 +399,35 @@ std::unique_ptr<Shader> ScanTarget::svideo_to_rgb_shader(int colour_cycle_numera
}
std::unique_ptr<Shader> ScanTarget::composite_to_svideo_shader(int colour_cycle_numerator, int colour_cycle_denominator, int processing_width) {
const float cycles_per_expanded_line = (float(colour_cycle_numerator) / float(colour_cycle_denominator)) / (float(processing_width) / float(LineBufferWidth));
const SignalProcessing::FIRFilter filter(11, float(LineBufferWidth), 0.0f, cycles_per_expanded_line * 0.5f);
const auto coefficients = filter.get_coefficients();
return nullptr;
auto coefficients = coefficients_for_filter(colour_cycle_numerator, colour_cycle_denominator, processing_width, 0.75f);
auto shader = std::unique_ptr<Shader>(new Shader(
glsl_globals(ShaderType::ProcessedScan) + glsl_default_vertex_shader(ShaderType::ProcessedScan),
"#version 150\n"
"in vec2 textureCoordinates[11];"
"in float compositeAngle;"
"in float oneOverCompositeAmplitude;"
"uniform vec4 textureWeights[3];"
"uniform sampler2D textureName;"
"out vec3 fragColour;"
"void main() {"
"vec4 samples[3] = vec4[3]("
"vec4(texture(textureName, textureCoordinates[0]).r, texture(textureName, textureCoordinates[1]).r, texture(textureName, textureCoordinates[2]).r, texture(textureName, textureCoordinates[3]).r),"
"vec4(texture(textureName, textureCoordinates[4]).r, texture(textureName, textureCoordinates[5]).r, texture(textureName, textureCoordinates[6]).r, texture(textureName, textureCoordinates[7]).r),"
"vec4(texture(textureName, textureCoordinates[8]).r, texture(textureName, textureCoordinates[9]).r, texture(textureName, textureCoordinates[10]).r, 0.0)"
");"
"float luma = dot(textureWeights[0], samples[0]) + dot(textureWeights[1], samples[1]) + dot(textureWeights[2], samples[2]);"
"vec2 quadrature = vec2(cos(compositeAngle), sin(compositeAngle));"
"vec2 chroma = ((samples[1].y - luma) * oneOverCompositeAmplitude)*quadrature;"
"fragColour = vec3(luma, chroma*0.5 + vec2(0.5));"
"}",
attribute_bindings(ShaderType::ProcessedScan)
));
coefficients.push_back(0.0f);
shader->set_uniform("textureWeights", 4, 3, coefficients.data());
return shader;
}