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mirror of https://github.com/TomHarte/CLK.git synced 2024-12-29 13:29:46 +00:00
CLK/Outputs/CRT/Internals/CRTOpenGL.cpp

819 lines
29 KiB
C++

// CRTOpenGL.cpp
// Clock Signal
//
// Created by Thomas Harte on 03/02/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "CRT.hpp"
#include <stdlib.h>
#include <math.h>
#include "CRTOpenGL.hpp"
#include "../../../SignalProcessing/FIRFilter.hpp"
#include "Shaders/OutputShader.hpp"
static const GLint internalFormatForDepth(size_t depth)
{
switch(depth)
{
default: return GL_FALSE;
case 1: return GL_R8UI;
case 2: return GL_RG8UI;
case 3: return GL_RGB8UI;
case 4: return GL_RGBA8UI;
}
}
static const GLenum formatForDepth(size_t depth)
{
switch(depth)
{
default: return GL_FALSE;
case 1: return GL_RED_INTEGER;
case 2: return GL_RG_INTEGER;
case 3: return GL_RGB_INTEGER;
case 4: return GL_RGBA_INTEGER;
}
}
static int getCircularRanges(GLsizei start, GLsizei end, GLsizei buffer_length, GLsizei granularity, GLsizei *ranges)
{
GLsizei startOffset = start%granularity;
if(startOffset)
{
start -= startOffset;
}
GLsizei length = end - start;
if(!length) return 0;
if(length > buffer_length)
{
ranges[0] = 0;
ranges[1] = buffer_length;
return 1;
}
else
{
ranges[0] = start % buffer_length;
if(ranges[0]+length < buffer_length)
{
ranges[1] = length;
return 1;
}
else
{
ranges[1] = buffer_length - ranges[0];
ranges[2] = 0;
ranges[3] = length - ranges[1];
return 2;
}
}
}
using namespace Outputs::CRT;
namespace {
static const GLenum composite_texture_unit = GL_TEXTURE0;
static const GLenum filtered_y_texture_unit = GL_TEXTURE1;
static const GLenum filtered_texture_unit = GL_TEXTURE2;
static const GLenum source_data_texture_unit = GL_TEXTURE3;
}
OpenGLOutputBuilder::OpenGLOutputBuilder(unsigned int buffer_depth) :
_output_mutex(new std::mutex),
_visible_area(Rect(0, 0, 1, 1)),
_composite_src_output_y(0),
_cleared_composite_output_y(0),
_composite_shader(nullptr),
_rgb_shader(nullptr),
_output_buffer_data(nullptr),
_source_buffer_data(nullptr),
_input_texture_data(nullptr),
_output_buffer_data_pointer(0),
_drawn_output_buffer_data_pointer(0),
_source_buffer_data_pointer(0),
_drawn_source_buffer_data_pointer(0)
{
_buffer_builder = std::unique_ptr<CRTInputBufferBuilder>(new CRTInputBufferBuilder(buffer_depth));
glBlendFunc(GL_SRC_ALPHA, GL_CONSTANT_COLOR);
glBlendColor(0.4f, 0.4f, 0.4f, 0.5f);
// Create intermediate textures and bind to slots 0, 1 and 2
glActiveTexture(composite_texture_unit);
compositeTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight));
compositeTexture->bind_texture();
glActiveTexture(filtered_y_texture_unit);
filteredYTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight));
filteredYTexture->bind_texture();
glActiveTexture(filtered_texture_unit);
filteredTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight));
filteredTexture->bind_texture();
// create the surce texture
glGenTextures(1, &textureName);
glActiveTexture(source_data_texture_unit);
glBindTexture(GL_TEXTURE_2D, textureName);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, internalFormatForDepth(_buffer_builder->bytes_per_pixel), InputBufferBuilderWidth, InputBufferBuilderHeight, 0, formatForDepth(_buffer_builder->bytes_per_pixel), GL_UNSIGNED_BYTE, nullptr);
// create a pixel unpack buffer
glGenBuffers(1, &_input_texture_array);
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, _input_texture_array);
_input_texture_array_size = (GLsizeiptr)(InputBufferBuilderWidth * InputBufferBuilderHeight * _buffer_builder->bytes_per_pixel);
glBufferData(GL_PIXEL_UNPACK_BUFFER, _input_texture_array_size, NULL, GL_STREAM_DRAW);
// map the buffer for clients
_input_texture_data = (uint8_t *)glMapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, _input_texture_array_size, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
// create the output vertex array
glGenVertexArrays(1, &output_vertex_array);
// create a buffer for output vertex attributes
glGenBuffers(1, &output_array_buffer);
glBindBuffer(GL_ARRAY_BUFFER, output_array_buffer);
glBufferData(GL_ARRAY_BUFFER, OutputVertexBufferDataSize, NULL, GL_STREAM_DRAW);
// map that buffer too, for any CRT activity that may occur before the first draw
_output_buffer_data = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, OutputVertexBufferDataSize, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
// create the source vertex array
glGenVertexArrays(1, &source_vertex_array);
// create a buffer for source vertex attributes
glGenBuffers(1, &source_array_buffer);
glBindBuffer(GL_ARRAY_BUFFER, source_array_buffer);
glBufferData(GL_ARRAY_BUFFER, SourceVertexBufferDataSize, NULL, GL_STREAM_DRAW);
// map that buffer too, for any CRT activity that may occur before the first draw
_source_buffer_data = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, SourceVertexBufferDataSize, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
// map back the default framebuffer
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
OpenGLOutputBuilder::~OpenGLOutputBuilder()
{
glUnmapBuffer(GL_ARRAY_BUFFER);
glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
glDeleteTextures(1, &textureName);
glDeleteBuffers(1, &_input_texture_array);
glDeleteBuffers(1, &output_array_buffer);
glDeleteBuffers(1, &source_array_buffer);
glDeleteVertexArrays(1, &output_vertex_array);
free(_composite_shader);
free(_rgb_shader);
}
void OpenGLOutputBuilder::draw_frame(unsigned int output_width, unsigned int output_height, bool only_if_dirty)
{
// establish essentials
if(!composite_input_shader_program && !rgb_shader_program)
{
prepare_composite_input_shader();
prepare_source_vertex_array();
prepare_composite_output_shader();
prepare_rgb_output_shader();
prepare_output_vertex_array();
set_timing_uniforms();
set_colour_space_uniforms();
// This should return either an actual framebuffer number, if this is a target with a framebuffer intended for output,
// or 0 if no framebuffer is bound, in which case 0 is also what we want to supply to bind the implied framebuffer. So
// it works either way.
glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *)&defaultFramebuffer);
// TODO: is this sustainable, cross-platform? If so, why store it at all?
defaultFramebuffer = 0;
}
// lock down any further work on the current frame
_output_mutex->lock();
// release the mapping, giving up on trying to draw if data has been lost
glBindBuffer(GL_ARRAY_BUFFER, output_array_buffer);
glUnmapBuffer(GL_ARRAY_BUFFER);
glBindBuffer(GL_ARRAY_BUFFER, source_array_buffer);
glUnmapBuffer(GL_ARRAY_BUFFER);
glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
// upload more source pixel data if any; we'll always resubmit the last line submitted last
// time as it may have had extra data appended to it
if(_buffer_builder->_write_y_position < _buffer_builder->last_uploaded_line)
{
glTexSubImage2D( GL_TEXTURE_2D, 0,
0, (GLint)_buffer_builder->last_uploaded_line,
InputBufferBuilderWidth, (GLint)(InputBufferBuilderHeight - _buffer_builder->last_uploaded_line),
formatForDepth(_buffer_builder->bytes_per_pixel), GL_UNSIGNED_BYTE,
(void *)(_buffer_builder->last_uploaded_line * InputBufferBuilderWidth * _buffer_builder->bytes_per_pixel));
_buffer_builder->last_uploaded_line = 0;
}
if(_buffer_builder->_write_y_position > _buffer_builder->last_uploaded_line)
{
glTexSubImage2D( GL_TEXTURE_2D, 0,
0, (GLint)_buffer_builder->last_uploaded_line,
InputBufferBuilderWidth, (GLint)(1 + _buffer_builder->_next_write_y_position - _buffer_builder->last_uploaded_line),
formatForDepth(_buffer_builder->bytes_per_pixel), GL_UNSIGNED_BYTE,
(void *)(_buffer_builder->last_uploaded_line * InputBufferBuilderWidth * _buffer_builder->bytes_per_pixel));
_buffer_builder->last_uploaded_line = _buffer_builder->_next_write_y_position;
}
// for television, update intermediate buffers and then draw; for a monitor, just draw
if(_output_device == Television || !rgb_shader_program)
{
// decide how much to draw
if(_drawn_source_buffer_data_pointer != _source_buffer_data_pointer)
{
// determine how many lines are newly reclaimed; they'll need to be cleared
GLsizei clearing_zones[4], drawing_zones[4];
int number_of_clearing_zones = getCircularRanges(_cleared_composite_output_y+1, _composite_src_output_y+1, IntermediateBufferHeight, 1, clearing_zones);
int number_of_drawing_zones = getCircularRanges(_drawn_source_buffer_data_pointer, _source_buffer_data_pointer, SourceVertexBufferDataSize, 2*SourceVertexSize, drawing_zones);
_composite_src_output_y %= IntermediateBufferHeight;
_cleared_composite_output_y = _composite_src_output_y;
_source_buffer_data_pointer %= SourceVertexBufferDataSize;
_drawn_source_buffer_data_pointer = _source_buffer_data_pointer;
// all drawing will be from the source vertex array and without blending
glBindVertexArray(source_vertex_array);
glDisable(GL_BLEND);
OpenGL::TextureTarget *targets[] = {
compositeTexture.get(),
filteredYTexture.get(),
filteredTexture.get()
};
OpenGL::Shader *shaders[] = {
composite_input_shader_program.get(),
composite_y_filter_shader_program.get(),
composite_chrominance_filter_shader_program.get()
};
float clear_colours[][3] = {
{0.0, 0.0, 0.0},
{0.0, 0.5, 0.5},
{0.0, 0.0, 0.0}
};
for(int stage = 0; stage < 3; stage++)
{
// switch to the initial texture
targets[stage]->bind_framebuffer();
shaders[stage]->bind();
// clear as desired
if(number_of_clearing_zones)
{
glEnable(GL_SCISSOR_TEST);
glClearColor(clear_colours[stage][0], clear_colours[stage][1], clear_colours[stage][2], 1.0);
for(int c = 0; c < number_of_clearing_zones; c++)
{
glScissor(0, clearing_zones[c*2], IntermediateBufferWidth, clearing_zones[c*2 + 1]);
glClear(GL_COLOR_BUFFER_BIT);
}
glDisable(GL_SCISSOR_TEST);
}
// draw as desired
for(int c = 0; c < number_of_drawing_zones; c++)
{
glDrawArrays(GL_LINES, drawing_zones[c*2] / SourceVertexSize, drawing_zones[c*2 + 1] / SourceVertexSize);
}
}
// switch back to screen output
glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);
glViewport(0, 0, (GLsizei)output_width, (GLsizei)output_height);
glClearColor(0.0, 0.0, 0.0, 1.0);
}
// transfer to screen
perform_output_stage(output_width, output_height, composite_output_shader_program.get());
}
else
perform_output_stage(output_width, output_height, rgb_shader_program.get());
// drawing commands having been issued, reclaim the array buffer pointer
glBindBuffer(GL_ARRAY_BUFFER, output_array_buffer);
_output_buffer_data = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, OutputVertexBufferDataSize, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
glBindBuffer(GL_ARRAY_BUFFER, source_array_buffer);
_source_buffer_data = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, SourceVertexBufferDataSize, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
_input_texture_data = (uint8_t *)glMapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, _input_texture_array_size, GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
_output_mutex->unlock();
}
void OpenGLOutputBuilder::perform_output_stage(unsigned int output_width, unsigned int output_height, OpenGL::OutputShader *const shader)
{
if(shader)
{
// clear the buffer
// glClear(GL_COLOR_BUFFER_BIT);
// draw all pending lines
GLsizei drawing_zones[4];
int number_of_drawing_zones = getCircularRanges(_drawn_output_buffer_data_pointer, _output_buffer_data_pointer, OutputVertexBufferDataSize, 6*OutputVertexSize, drawing_zones);
_output_buffer_data_pointer %= SourceVertexBufferDataSize;
_output_buffer_data_pointer -= (_output_buffer_data_pointer%(6*OutputVertexSize));
_drawn_output_buffer_data_pointer = _output_buffer_data_pointer;
if(number_of_drawing_zones > 0)
{
glEnable(GL_BLEND);
// Ensure we're back on the output framebuffer, drawing from the output array buffer
glBindVertexArray(output_vertex_array);
// update uniforms (implicitly binding the shader)
shader->set_output_size(output_width, output_height, _visible_area);
// draw
for(int c = 0; c < number_of_drawing_zones; c++)
{
glDrawArrays(GL_TRIANGLE_STRIP, drawing_zones[c*2] / OutputVertexSize, drawing_zones[c*2 + 1] / OutputVertexSize);
}
}
}
}
void OpenGLOutputBuilder::set_openGL_context_will_change(bool should_delete_resources)
{
}
void OpenGLOutputBuilder::set_composite_sampling_function(const char *shader)
{
_composite_shader = strdup(shader);
}
void OpenGLOutputBuilder::set_rgb_sampling_function(const char *shader)
{
_rgb_shader = strdup(shader);
}
#pragma mark - Input vertex shader (i.e. from source data to intermediate line layout)
char *OpenGLOutputBuilder::get_input_vertex_shader(const char *input_position, const char *header)
{
char *result;
asprintf(&result,
"#version 150\n"
"in vec2 inputPosition;"
"in vec2 outputPosition;"
"in vec3 phaseAmplitudeAndOffset;"
"in float phaseTime;"
"uniform float phaseCyclesPerTick;"
"uniform ivec2 outputTextureSize;"
"uniform float extension;"
"\n%s\n"
"out vec2 inputPositionVarying;"
"out vec2 iInputPositionVarying;"
"out float phaseVarying;"
"out float amplitudeVarying;"
"out vec2 inputPositionsVarying[11];"
"void main(void)"
"{"
"vec2 extensionVector = vec2(extension, 0.0) * 2.0 * (phaseAmplitudeAndOffset.z - 0.5);"
"vec2 extendedInputPosition = %s + extensionVector;"
"vec2 extendedOutputPosition = outputPosition + extensionVector;"
"vec2 textureSize = vec2(textureSize(texID, 0));"
"iInputPositionVarying = extendedInputPosition;"
"inputPositionVarying = (extendedInputPosition + vec2(0.0, 0.5)) / textureSize;"
"textureSize = textureSize * vec2(1.0);"
"inputPositionsVarying[0] = inputPositionVarying - (vec2(10.0, 0.0) / textureSize);"
"inputPositionsVarying[1] = inputPositionVarying - (vec2(8.0, 0.0) / textureSize);"
"inputPositionsVarying[2] = inputPositionVarying - (vec2(6.0, 0.0) / textureSize);"
"inputPositionsVarying[3] = inputPositionVarying - (vec2(4.0, 0.0) / textureSize);"
"inputPositionsVarying[4] = inputPositionVarying - (vec2(2.0, 0.0) / textureSize);"
"inputPositionsVarying[5] = inputPositionVarying;"
"inputPositionsVarying[6] = inputPositionVarying + (vec2(2.0, 0.0) / textureSize);"
"inputPositionsVarying[7] = inputPositionVarying + (vec2(4.0, 0.0) / textureSize);"
"inputPositionsVarying[8] = inputPositionVarying + (vec2(6.0, 0.0) / textureSize);"
"inputPositionsVarying[9] = inputPositionVarying + (vec2(8.0, 0.0) / textureSize);"
"inputPositionsVarying[10] = inputPositionVarying + (vec2(10.0, 0.0) / textureSize);"
"phaseVarying = (phaseCyclesPerTick * (extendedOutputPosition.x - phaseTime) + phaseAmplitudeAndOffset.x) * 2.0 * 3.141592654;"
"amplitudeVarying = 0.33;" // phaseAmplitudeAndOffset.y
"vec2 eyePosition = 2.0*(extendedOutputPosition / outputTextureSize) - vec2(1.0) + vec2(0.5)/textureSize;"
"gl_Position = vec4(eyePosition, 0.0, 1.0);"
"}", header, input_position);
return result;
}
char *OpenGLOutputBuilder::get_input_fragment_shader()
{
char *composite_shader = _composite_shader;
if(!composite_shader)
{
asprintf(&composite_shader,
"%s\n"
"uniform mat3 rgbToLumaChroma;"
"float composite_sample(usampler2D texID, vec2 coordinate, vec2 iCoordinate, float phase, float amplitude)"
"{"
"vec3 rgbColour = clamp(rgb_sample(texID, coordinate, iCoordinate), vec3(0.0), vec3(1.0));"
"vec3 lumaChromaColour = rgbToLumaChroma * rgbColour;"
"vec2 quadrature = vec2(cos(phase), -sin(phase)) * amplitude;"
"return dot(lumaChromaColour, vec3(1.0 - amplitude, quadrature));"
"}",
_rgb_shader);
// TODO: use YIQ if this is NTSC
}
char *result;
asprintf(&result,
"#version 150\n"
"in vec2 inputPositionVarying;"
"in vec2 iInputPositionVarying;"
"in float phaseVarying;"
"in float amplitudeVarying;"
"out vec4 fragColour;"
"uniform usampler2D texID;"
"\n%s\n"
"void main(void)"
"{"
"fragColour = vec4(composite_sample(texID, inputPositionVarying, iInputPositionVarying, phaseVarying, amplitudeVarying));"
"}"
, composite_shader);
if(!_composite_shader) free(composite_shader);
return result;
}
char *OpenGLOutputBuilder::get_y_filter_fragment_shader()
{
return strdup(
"#version 150\n"
"in float phaseVarying;"
"in float amplitudeVarying;"
"in vec2 inputPositionsVarying[11];"
"uniform vec4 weights[3];"
"out vec3 fragColour;"
"uniform sampler2D texID;"
"void main(void)"
"{"
"vec4 samples[3] = vec4[]("
"vec4("
"texture(texID, inputPositionsVarying[0]).r,"
"texture(texID, inputPositionsVarying[1]).r,"
"texture(texID, inputPositionsVarying[2]).r,"
"texture(texID, inputPositionsVarying[3]).r"
"),"
"vec4("
"texture(texID, inputPositionsVarying[4]).r,"
"texture(texID, inputPositionsVarying[5]).r,"
"texture(texID, inputPositionsVarying[6]).r,"
"texture(texID, inputPositionsVarying[7]).r"
"),"
"vec4("
"texture(texID, inputPositionsVarying[8]).r,"
"texture(texID, inputPositionsVarying[9]).r,"
"texture(texID, inputPositionsVarying[10]).r,"
"0.0"
")"
");"
"float luminance = "
"dot(vec3("
"dot(samples[0], weights[0]),"
"dot(samples[1], weights[1]),"
"dot(samples[2], weights[2])"
"), vec3(1.0)) / (1.0 - amplitudeVarying);"
"float chrominance = 0.5 * (samples[1].y - luminance) / amplitudeVarying;"
"vec2 quadrature = vec2(cos(phaseVarying), -sin(phaseVarying));"
"fragColour = vec3(luminance, vec2(0.5) + (chrominance * quadrature));"
"}");
}
char *OpenGLOutputBuilder::get_chrominance_filter_fragment_shader()
{
return strdup(
"#version 150\n"
"in float phaseVarying;"
"in float amplitudeVarying;"
"in vec2 inputPositionsVarying[11];"
"uniform vec4 weights[3];"
"out vec3 fragColour;"
"uniform sampler2D texID;"
"uniform mat3 lumaChromaToRGB;"
"void main(void)"
"{"
"vec3 centreSample = texture(texID, inputPositionsVarying[5]).rgb;"
"vec2 samples[] = vec2[]("
"texture(texID, inputPositionsVarying[0]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[1]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[2]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[3]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[4]).gb - vec2(0.5),"
"centreSample.gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[6]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[7]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[8]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[9]).gb - vec2(0.5),"
"texture(texID, inputPositionsVarying[10]).gb - vec2(0.5)"
");"
"vec4 channel1[] = vec4[]("
"vec4(samples[0].r, samples[1].r, samples[2].r, samples[3].r),"
"vec4(samples[4].r, samples[5].r, samples[6].r, samples[7].r),"
"vec4(samples[8].r, samples[9].r, samples[10].r, 0.0)"
");"
"vec4 channel2[] = vec4[]("
"vec4(samples[0].g, samples[1].g, samples[2].g, samples[3].g),"
"vec4(samples[4].g, samples[5].g, samples[6].g, samples[7].g),"
"vec4(samples[8].g, samples[9].g, samples[10].g, 0.0)"
");"
"vec3 lumaChromaColour = vec3(centreSample.r,"
"dot(vec3("
"dot(channel1[0], weights[0]),"
"dot(channel1[1], weights[1]),"
"dot(channel1[2], weights[2])"
"), vec3(1.0)) + 0.5,"
"dot(vec3("
"dot(channel2[0], weights[0]),"
"dot(channel2[1], weights[1]),"
"dot(channel2[2], weights[2])"
"), vec3(1.0)) + 0.5"
");"
"vec3 lumaChromaColourInRange = (lumaChromaColour - vec3(0.0, 0.5, 0.5)) * vec3(1.0, 2.0, 2.0);"
"fragColour = lumaChromaToRGB * lumaChromaColourInRange;"
"}");
}
#pragma mark - Intermediate vertex shaders (i.e. from intermediate line layout to intermediate line layout)
#pragma mark - Program compilation
std::unique_ptr<OpenGL::Shader> OpenGLOutputBuilder::prepare_intermediate_shader(const char *input_position, const char *header, char *fragment_shader, GLenum texture_unit, bool extends)
{
std::unique_ptr<OpenGL::Shader> shader;
char *vertex_shader = get_input_vertex_shader(input_position, header);
if(vertex_shader && fragment_shader)
{
OpenGL::Shader::AttributeBinding bindings[] =
{
{"inputPosition", 0},
{"outputPosition", 1},
{"phaseAmplitudeAndOffset", 2},
{"phaseTime", 3},
{nullptr}
};
shader = std::unique_ptr<OpenGL::Shader>(new OpenGL::Shader(vertex_shader, fragment_shader, bindings));
GLint texIDUniform = shader->get_uniform_location("texID");
GLint outputTextureSizeUniform = shader->get_uniform_location("outputTextureSize");
shader->bind();
glUniform1i(texIDUniform, (GLint)(texture_unit - GL_TEXTURE0));
glUniform2i(outputTextureSizeUniform, IntermediateBufferWidth, IntermediateBufferHeight);
}
free(vertex_shader);
free(fragment_shader);
return shader;
}
void OpenGLOutputBuilder::prepare_composite_input_shader()
{
composite_input_shader_program = prepare_intermediate_shader("inputPosition", "uniform usampler2D texID;", get_input_fragment_shader(), source_data_texture_unit, false);
composite_y_filter_shader_program = prepare_intermediate_shader("outputPosition", "uniform sampler2D texID;", get_y_filter_fragment_shader(), composite_texture_unit, true);
composite_chrominance_filter_shader_program = prepare_intermediate_shader("outputPosition", "uniform sampler2D texID;", get_chrominance_filter_fragment_shader(), filtered_y_texture_unit, true);
}
void OpenGLOutputBuilder::prepare_source_vertex_array()
{
if(composite_input_shader_program)
{
GLint inputPositionAttribute = composite_input_shader_program->get_attrib_location("inputPosition");
GLint outputPositionAttribute = composite_input_shader_program->get_attrib_location("outputPosition");
GLint phaseAmplitudeAndOffsetAttribute = composite_input_shader_program->get_attrib_location("phaseAmplitudeAndOffset");
GLint phaseTimeAttribute = composite_input_shader_program->get_attrib_location("phaseTime");
glBindVertexArray(source_vertex_array);
glEnableVertexAttribArray((GLuint)inputPositionAttribute);
glEnableVertexAttribArray((GLuint)outputPositionAttribute);
glEnableVertexAttribArray((GLuint)phaseAmplitudeAndOffsetAttribute);
glEnableVertexAttribArray((GLuint)phaseTimeAttribute);
const GLsizei vertexStride = SourceVertexSize;
glBindBuffer(GL_ARRAY_BUFFER, source_array_buffer);
glVertexAttribPointer((GLuint)inputPositionAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)SourceVertexOffsetOfInputPosition);
glVertexAttribPointer((GLuint)outputPositionAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)SourceVertexOffsetOfOutputPosition);
glVertexAttribPointer((GLuint)phaseAmplitudeAndOffsetAttribute, 3, GL_UNSIGNED_BYTE, GL_TRUE, vertexStride, (void *)SourceVertexOffsetOfPhaseAmplitudeAndOffset);
glVertexAttribPointer((GLuint)phaseTimeAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)SourceVertexOffsetOfPhaseTime);
}
}
void OpenGLOutputBuilder::prepare_rgb_output_shader()
{
const char *rgb_shader = _rgb_shader;
if(!_rgb_shader)
{
rgb_shader =
"vec3 rgb_sample(usampler2D sampler, vec2 coordinate, vec2 icoordinate)"
"{"
"return texture(sampler, coordinate).rgb / vec3(255.0);"
"}";
}
rgb_shader_program = OpenGL::OutputShader::make_shader(rgb_shader, "rgb_sample(texID, srcCoordinatesVarying, iSrcCoordinatesVarying)", true);
rgb_shader_program->set_source_texture_unit(source_data_texture_unit);
}
void OpenGLOutputBuilder::prepare_composite_output_shader()
{
composite_output_shader_program = OpenGL::OutputShader::make_shader("", "texture(texID, srcCoordinatesVarying).rgb", false);
composite_output_shader_program->set_source_texture_unit(filtered_texture_unit);
}
void OpenGLOutputBuilder::prepare_output_vertex_array()
{
if(rgb_shader_program)
{
GLint positionAttribute = rgb_shader_program->get_attrib_location("position");
GLint textureCoordinatesAttribute = rgb_shader_program->get_attrib_location("srcCoordinates");
GLint lateralAttribute = rgb_shader_program->get_attrib_location("lateral");
glBindVertexArray(output_vertex_array);
glEnableVertexAttribArray((GLuint)positionAttribute);
glEnableVertexAttribArray((GLuint)textureCoordinatesAttribute);
glEnableVertexAttribArray((GLuint)lateralAttribute);
const GLsizei vertexStride = OutputVertexSize;
glBindBuffer(GL_ARRAY_BUFFER, output_array_buffer);
glVertexAttribPointer((GLuint)positionAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)OutputVertexOffsetOfPosition);
glVertexAttribPointer((GLuint)textureCoordinatesAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)OutputVertexOffsetOfTexCoord);
glVertexAttribPointer((GLuint)lateralAttribute, 1, GL_UNSIGNED_BYTE, GL_FALSE, vertexStride, (void *)OutputVertexOffsetOfLateral);
}
}
#pragma mark - Public Configuration
void OpenGLOutputBuilder::set_output_device(OutputDevice output_device)
{
if(_output_device != output_device)
{
_output_device = output_device;
_composite_src_output_y = 0;
}
}
void OpenGLOutputBuilder::set_timing(unsigned int cycles_per_line, unsigned int height_of_display, unsigned int horizontal_scan_period, unsigned int vertical_scan_period, unsigned int vertical_period_divider)
{
_cycles_per_line = cycles_per_line;
_height_of_display = height_of_display;
_horizontal_scan_period = horizontal_scan_period;
_vertical_scan_period = vertical_scan_period;
_vertical_period_divider = vertical_period_divider;
set_timing_uniforms();
}
#pragma mark - Internal Configuration
void OpenGLOutputBuilder::set_colour_space_uniforms()
{
_output_mutex->lock();
GLfloat rgbToYUV[] = {0.299f, -0.14713f, 0.615f, 0.587f, -0.28886f, -0.51499f, 0.114f, 0.436f, -0.10001f};
GLfloat yuvToRGB[] = {1.0f, 1.0f, 1.0f, 0.0f, -0.39465f, 2.03211f, 1.13983f, -0.58060f, 0.0f};
GLfloat rgbToYIQ[] = {0.299f, 0.596f, 0.211f, 0.587f, -0.274f, -0.523f, 0.114f, -0.322f, 0.312f};
GLfloat yiqToRGB[] = {1.0f, 1.0f, 1.0f, 0.956f, -0.272f, -1.106f, 0.621f, -0.647f, 1.703f};
GLfloat *fromRGB, *toRGB;
switch(_colour_space)
{
case ColourSpace::YIQ:
fromRGB = rgbToYIQ;
toRGB = yiqToRGB;
break;
case ColourSpace::YUV:
fromRGB = rgbToYUV;
toRGB = yuvToRGB;
break;
}
if(composite_input_shader_program)
{
composite_input_shader_program->bind();
GLint uniform = composite_input_shader_program->get_uniform_location("rgbToLumaChroma");
if(uniform >= 0)
{
glUniformMatrix3fv(uniform, 1, GL_FALSE, fromRGB);
}
}
if(composite_chrominance_filter_shader_program)
{
composite_chrominance_filter_shader_program->bind();
GLint uniform = composite_chrominance_filter_shader_program->get_uniform_location("lumaChromaToRGB");
if(uniform >= 0)
{
glUniformMatrix3fv(uniform, 1, GL_FALSE, toRGB);
}
}
_output_mutex->unlock();
}
void OpenGLOutputBuilder::set_timing_uniforms()
{
_output_mutex->lock();
OpenGL::Shader *intermediate_shaders[] = {
composite_input_shader_program.get(),
composite_y_filter_shader_program.get(),
composite_chrominance_filter_shader_program.get()
};
bool extends = false;
for(int c = 0; c < 3; c++)
{
if(intermediate_shaders[c])
{
intermediate_shaders[c]->bind();
GLint phaseCyclesPerTickUniform = intermediate_shaders[c]->get_uniform_location("phaseCyclesPerTick");
GLint extensionUniform = intermediate_shaders[c]->get_uniform_location("extension");
float phaseCyclesPerTick = (float)_colour_cycle_numerator / (float)(_colour_cycle_denominator * _cycles_per_line);
glUniform1f(phaseCyclesPerTickUniform, phaseCyclesPerTick);
glUniform1f(extensionUniform, extends ? ceilf(1.0f / phaseCyclesPerTick) : 0.0f);
}
extends = true;
}
OpenGL::OutputShader *output_shaders[] = {
rgb_shader_program.get(),
composite_output_shader_program.get()
};
for(int c = 0; c < 2; c++)
{
if(output_shaders[c])
{
output_shaders[c]->set_timing(_height_of_display, _cycles_per_line, _horizontal_scan_period, _vertical_scan_period, _vertical_period_divider);
}
}
float colour_subcarrier_frequency = (float)_colour_cycle_numerator / (float)_colour_cycle_denominator;
GLint weightsUniform;
float weights[12];
if(composite_y_filter_shader_program)
{
SignalProcessing::FIRFilter luminance_filter(11, _cycles_per_line * 0.5f, 0.0f, colour_subcarrier_frequency * 0.5f, SignalProcessing::FIRFilter::DefaultAttenuation);
composite_y_filter_shader_program->bind();
weightsUniform = composite_y_filter_shader_program->get_uniform_location("weights");
luminance_filter.get_coefficients(weights);
glUniform4fv(weightsUniform, 3, weights);
}
if(composite_chrominance_filter_shader_program)
{
SignalProcessing::FIRFilter chrominance_filter(11, _cycles_per_line * 0.5f, 0.0f, colour_subcarrier_frequency * 0.5f, SignalProcessing::FIRFilter::DefaultAttenuation);
composite_chrominance_filter_shader_program->bind();
weightsUniform = composite_chrominance_filter_shader_program->get_uniform_location("weights");
chrominance_filter.get_coefficients(weights);
glUniform4fv(weightsUniform, 3, weights);
}
_output_mutex->unlock();
}