1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-12-25 18:30:21 +00:00
CLK/Outputs/CRT/CRTOpenGL.cpp

375 lines
15 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 "OpenGL.hpp"
#include "TextureTarget.hpp"
#include "Shader.hpp"
#include "CRTOpenGL.hpp"
using namespace Outputs;
struct CRT::OpenGLState {
std::unique_ptr<OpenGL::Shader> shaderProgram;
GLuint arrayBuffers[kCRTNumberOfFrames], vertexArrays[kCRTNumberOfFrames];
GLint positionAttribute;
GLint textureCoordinatesAttribute;
GLint lateralAttribute;
GLint timestampAttribute;
GLint windowSizeUniform, timestampBaseUniform;
GLint boundsOriginUniform, boundsSizeUniform;
GLuint textureName, shadowMaskTextureName;
GLuint defaultFramebuffer;
std::unique_ptr<OpenGL::TextureTarget> compositeTexture; // receives raw composite levels
std::unique_ptr<OpenGL::TextureTarget> filteredYTexture; // receives filtered Y in the R channel plus unfiltered I/U and Q/V in G and B
std::unique_ptr<OpenGL::TextureTarget> filteredTexture; // receives filtered YIQ or YUV
};
static GLenum formatForDepth(size_t depth)
{
switch(depth)
{
default: return GL_FALSE;
case 1: return GL_RED;
case 2: return GL_RG;
case 3: return GL_RGB;
case 4: return GL_RGBA;
}
}
void CRT::construct_openGL()
{
_openGL_state = nullptr;
_composite_shader = _rgb_shader = nullptr;
}
void CRT::destruct_openGL()
{
delete _openGL_state;
_openGL_state = nullptr;
if(_composite_shader) free(_composite_shader);
if(_rgb_shader) free(_rgb_shader);
}
void CRT::draw_frame(unsigned int output_width, unsigned int output_height, bool only_if_dirty)
{
// establish essentials
if(!_openGL_state)
{
_openGL_state = new OpenGLState;
glGenTextures(1, &_openGL_state->textureName);
glBindTexture(GL_TEXTURE_2D, _openGL_state->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);
GLenum format = formatForDepth(_buffer_builder->buffers[0].bytes_per_pixel);
glTexImage2D(GL_TEXTURE_2D, 0, (GLint)format, CRTInputBufferBuilderWidth, CRTInputBufferBuilderHeight, 0, format, GL_UNSIGNED_BYTE, _buffer_builder->buffers[0].data);
glGenVertexArrays(kCRTNumberOfFrames, _openGL_state->vertexArrays);
glGenBuffers(kCRTNumberOfFrames, _openGL_state->arrayBuffers);
prepare_shader();
for(int c = 0; c < kCRTNumberOfFrames; c++)
{
glBindBuffer(GL_ARRAY_BUFFER, _openGL_state->arrayBuffers[c]);
glBindVertexArray(_openGL_state->vertexArrays[c]);
prepare_vertex_array();
}
glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *)&_openGL_state->defaultFramebuffer);
// _openGL_state->compositeTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(2048, kCRTFrameIntermediateBufferHeight));
// _openGL_state->filteredYTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(2048, kCRTFrameIntermediateBufferHeight));
// _openGL_state->filteredTexture = std::unique_ptr<OpenGL::TextureTarget>(new OpenGL::TextureTarget(2048, kCRTFrameIntermediateBufferHeight));
}
// lock down any further work on the current frame
_output_mutex->lock();
// update uniforms
push_size_uniforms(output_width, output_height);
// clear the buffer
glClear(GL_COLOR_BUFFER_BIT);
// 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
GLenum format = formatForDepth(_buffer_builder->buffers[0].bytes_per_pixel);
if(_buffer_builder->_next_write_y_position < _buffer_builder->last_uploaded_line)
{
glTexSubImage2D(GL_TEXTURE_2D, 0,
0, (GLint)_buffer_builder->last_uploaded_line,
CRTInputBufferBuilderWidth, (GLint)(CRTInputBufferBuilderHeight - _buffer_builder->last_uploaded_line),
format, GL_UNSIGNED_BYTE,
&_buffer_builder->buffers[0].data[_buffer_builder->last_uploaded_line * CRTInputBufferBuilderWidth * _buffer_builder->buffers[0].bytes_per_pixel]);
_buffer_builder->last_uploaded_line = 0;
}
if(_buffer_builder->_next_write_y_position > _buffer_builder->last_uploaded_line)
{
glTexSubImage2D(GL_TEXTURE_2D, 0,
0, (GLint)_buffer_builder->last_uploaded_line,
CRTInputBufferBuilderWidth, (GLint)(1 + _buffer_builder->_next_write_y_position - _buffer_builder->last_uploaded_line),
format, GL_UNSIGNED_BYTE,
&_buffer_builder->buffers[0].data[_buffer_builder->last_uploaded_line * CRTInputBufferBuilderWidth * _buffer_builder->buffers[0].bytes_per_pixel]);
_buffer_builder->last_uploaded_line = _buffer_builder->_next_write_y_position;
}
// draw all sitting frames
int run = _run_write_pointer;
// printf("%d: %zu v %zu\n", run, _run_builders[run]->uploaded_vertices, _run_builders[run]->number_of_vertices);
GLint total_age = 0;
for(int c = 0; c < kCRTNumberOfFrames; c++)
{
// update the total age at the start of this set of runs
total_age += _run_builders[run]->duration;
if(_run_builders[run]->number_of_vertices > 0)
{
glUniform1f(_openGL_state->timestampBaseUniform, (GLfloat)total_age);
// bind the vertex array
glBindVertexArray(_openGL_state->vertexArrays[run]);
// bind this frame's array buffer
glBindBuffer(GL_ARRAY_BUFFER, _openGL_state->arrayBuffers[run]);
if(_run_builders[run]->uploaded_vertices != _run_builders[run]->number_of_vertices)
{
// glBufferSubData can only replace existing data, not grow the pool, so for now we'll just take this hit
uint8_t *data = &_run_builders[run]->_input_runs[0];
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)(_run_builders[run]->number_of_vertices * kCRTSizeOfVertex), data, GL_DYNAMIC_DRAW);
_run_builders[run]->uploaded_vertices = _run_builders[run]->number_of_vertices;
}
// draw this frame
glDrawArrays(GL_TRIANGLES, 0, (GLsizei)_run_builders[run]->number_of_vertices);
}
// advance back in time
run = (run - 1 + kCRTNumberOfFrames) % kCRTNumberOfFrames;
}
_output_mutex->unlock();
}
void CRT::set_openGL_context_will_change(bool should_delete_resources)
{
_openGL_state = nullptr;
}
void CRT::push_size_uniforms(unsigned int output_width, unsigned int output_height)
{
if(_openGL_state->windowSizeUniform >= 0)
{
glUniform2f(_openGL_state->windowSizeUniform, output_width, output_height);
}
GLfloat outputAspectRatioMultiplier = ((float)output_width / (float)output_height) / (4.0f / 3.0f);
Rect _aspect_ratio_corrected_bounds = _visible_area;
GLfloat bonusWidth = (outputAspectRatioMultiplier - 1.0f) * _visible_area.size.width;
_aspect_ratio_corrected_bounds.origin.x -= bonusWidth * 0.5f * _aspect_ratio_corrected_bounds.size.width;
_aspect_ratio_corrected_bounds.size.width *= outputAspectRatioMultiplier;
if(_openGL_state->boundsOriginUniform >= 0)
glUniform2f(_openGL_state->boundsOriginUniform, (GLfloat)_aspect_ratio_corrected_bounds.origin.x, (GLfloat)_aspect_ratio_corrected_bounds.origin.y);
if(_openGL_state->boundsSizeUniform >= 0)
glUniform2f(_openGL_state->boundsSizeUniform, (GLfloat)_aspect_ratio_corrected_bounds.size.width, (GLfloat)_aspect_ratio_corrected_bounds.size.height);
}
void CRT::set_composite_sampling_function(const char *shader)
{
_composite_shader = strdup(shader);
}
void CRT::set_rgb_sampling_function(const char *shader)
{
_rgb_shader = strdup(shader);
}
char *CRT::get_vertex_shader()
{
// the main job of the vertex shader is just to map from an input area of [0,1]x[0,1], with the origin in the
// top left to OpenGL's [-1,1]x[-1,1] with the origin in the lower left, and to convert input data coordinates
// from integral to floating point; there's also some setup for NTSC, PAL or whatever.
// const char *const ntscVertexShaderGlobals =
// "out vec2 srcCoordinatesVarying[4];\n"
// "out float phase;\n";
//
// const char *const ntscVertexShaderBody =
// "phase = srcCoordinates.x * 6.283185308;\n"
// "\n"
// "srcCoordinatesVarying[0] = vec2(srcCoordinates.x / textureSize.x, (srcCoordinates.y + 0.5) / textureSize.y);\n"
// "srcCoordinatesVarying[3] = srcCoordinatesVarying[0] + vec2(0.375 / textureSize.x, 0.0);\n"
// "srcCoordinatesVarying[2] = srcCoordinatesVarying[0] + vec2(0.125 / textureSize.x, 0.0);\n"
// "srcCoordinatesVarying[1] = srcCoordinatesVarying[0] - vec2(0.125 / textureSize.x, 0.0);\n"
// "srcCoordinatesVarying[0] = srcCoordinatesVarying[0] - vec2(0.325 / textureSize.x, 0.0);\n";
return strdup(
"#version 150\n"
"in vec2 position;"
"in vec2 srcCoordinates;"
"in float lateral;"
"in float timestamp;"
"uniform vec2 boundsOrigin;"
"uniform vec2 boundsSize;"
"out float lateralVarying;"
"out vec2 shadowMaskCoordinates;"
"out float alpha;"
"uniform vec2 textureSize;"
"uniform float timestampBase;"
"uniform float ticksPerFrame;"
"const float shadowMaskMultiple = 600;"
"out vec2 srcCoordinatesVarying;"
"void main(void)"
"{"
"lateralVarying = lateral + 1.0707963267949;"
"shadowMaskCoordinates = position * vec2(shadowMaskMultiple, shadowMaskMultiple * 0.85057471264368);"
"srcCoordinatesVarying = vec2(srcCoordinates.x / textureSize.x, (srcCoordinates.y + 0.5) / textureSize.y);"
"float age = (timestampBase - timestamp) / ticksPerFrame;"
"alpha = min(10.0 * exp(-age * 2.0), 1.0);"
"vec2 mappedPosition = (position - boundsOrigin) / boundsSize;"
"gl_Position = vec4(mappedPosition.x * 2.0 - 1.0, 1.0 - mappedPosition.y * 2.0, 0.0, 1.0);"
"}");
}
char *CRT::get_fragment_shader()
{
// assumes y = [0, 1], i and q = [-0.5, 0.5]; therefore i components are multiplied by 1.1914 versus standard matrices, q by 1.0452
// const char *const yiqToRGB = "const mat3 yiqToRGB = mat3(1.0, 1.0, 1.0, 1.1389784, -0.3240608, -1.3176884, 0.6490692, -0.6762444, 1.7799756);";
// assumes y = [0,1], u and v = [-0.5, 0.5]; therefore u components are multiplied by 1.14678899082569, v by 0.8130081300813
// const char *const yuvToRGB = "const mat3 yiqToRGB = mat3(1.0, 1.0, 1.0, 0.0, -0.75213899082569, 2.33040137614679, 0.92669105691057, -0.4720325203252, 0.0);";
// const char *const ntscFragmentShaderGlobals =
// "in vec2 srcCoordinatesVarying[4];\n"
// "in float phase;\n"
// "\n"
// "// for conversion from i and q are in the range [-0.5, 0.5] (so i needs to be multiplied by 1.1914 and q by 1.0452)\n"
// "const mat3 yiqToRGB = mat3(1.0, 1.0, 1.0, 1.1389784, -0.3240608, -1.3176884, 0.6490692, -0.6762444, 1.7799756);\n";
// const char *const ntscFragmentShaderBody =
// "vec4 angles = vec4(phase) + vec4(-2.35619449019234, -0.78539816339745, 0.78539816339745, 2.35619449019234);\n"
// "vec4 samples = vec4("
// " sample(srcCoordinatesVarying[0], angles.x),"
// " sample(srcCoordinatesVarying[1], angles.y),"
// " sample(srcCoordinatesVarying[2], angles.z),"
// " sample(srcCoordinatesVarying[3], angles.w)"
// ");\n"
// "\n"
// "float y = dot(vec4(0.25), samples);\n"
// "samples -= vec4(y);\n"
// "\n"
// "float i = dot(cos(angles), samples);\n"
// "float q = dot(sin(angles), samples);\n"
// "\n"
// "fragColour = 5.0 * texture(shadowMaskTexID, shadowMaskCoordinates) * vec4(yiqToRGB * vec3(y, i, q), 1.0);//sin(lateralVarying));\n";
// dot(vec3(1.0/6.0, 2.0/3.0, 1.0/6.0), vec3(sample(srcCoordinatesVarying[0]), sample(srcCoordinatesVarying[0]), sample(srcCoordinatesVarying[0])));//sin(lateralVarying));\n";
return get_compound_shader(
"#version 150\n"
"in float lateralVarying;"
"in float alpha;"
"in vec2 shadowMaskCoordinates;"
"in vec2 srcCoordinatesVarying;"
"out vec4 fragColour;"
"uniform sampler2D texID;"
"uniform sampler2D shadowMaskTexID;"
"\n%s\n"
"void main(void)"
"{"
"fragColour = vec4(rgb_sample(srcCoordinatesVarying).rgb, alpha * sin(lateralVarying));" //
"}"
, _rgb_shader);
}
char *CRT::get_compound_shader(const char *base, const char *insert)
{
size_t totalLength = strlen(base) + strlen(insert) + 1;
char *text = new char[totalLength];
snprintf(text, totalLength, base, insert);
return text;
}
void CRT::prepare_shader()
{
char *vertex_shader = get_vertex_shader();
char *fragment_shader = get_fragment_shader();
_openGL_state->shaderProgram = std::unique_ptr<OpenGL::Shader>(new OpenGL::Shader(vertex_shader, fragment_shader));
_openGL_state->shaderProgram->bind();
_openGL_state->positionAttribute = _openGL_state->shaderProgram->get_attrib_location("position");
_openGL_state->textureCoordinatesAttribute = _openGL_state->shaderProgram->get_attrib_location("srcCoordinates");
_openGL_state->lateralAttribute = _openGL_state->shaderProgram->get_attrib_location("lateral");
_openGL_state->timestampAttribute = _openGL_state->shaderProgram->get_attrib_location("timestamp");
_openGL_state->windowSizeUniform = _openGL_state->shaderProgram->get_uniform_location("windowSize");
_openGL_state->boundsSizeUniform = _openGL_state->shaderProgram->get_uniform_location("boundsSize");
_openGL_state->boundsOriginUniform = _openGL_state->shaderProgram->get_uniform_location("boundsOrigin");
_openGL_state->timestampBaseUniform = _openGL_state->shaderProgram->get_uniform_location("timestampBase");
GLint texIDUniform = _openGL_state->shaderProgram->get_uniform_location("texID");
GLint shadowMaskTexIDUniform = _openGL_state->shaderProgram->get_uniform_location("shadowMaskTexID");
GLint textureSizeUniform = _openGL_state->shaderProgram->get_uniform_location("textureSize");
GLint ticksPerFrameUniform = _openGL_state->shaderProgram->get_uniform_location("ticksPerFrame");
glUniform1i(texIDUniform, 0);
glUniform1i(shadowMaskTexIDUniform, 1);
glUniform2f(textureSizeUniform, CRTInputBufferBuilderWidth, CRTInputBufferBuilderHeight);
glUniform1f(ticksPerFrameUniform, (GLfloat)(_cycles_per_line * _height_of_display));
}
void CRT::prepare_vertex_array()
{
glEnableVertexAttribArray((GLuint)_openGL_state->positionAttribute);
glEnableVertexAttribArray((GLuint)_openGL_state->textureCoordinatesAttribute);
glEnableVertexAttribArray((GLuint)_openGL_state->lateralAttribute);
glEnableVertexAttribArray((GLuint)_openGL_state->timestampAttribute);
const GLsizei vertexStride = kCRTSizeOfVertex;
glVertexAttribPointer((GLuint)_openGL_state->positionAttribute, 2, GL_UNSIGNED_SHORT, GL_TRUE, vertexStride, (void *)kCRTVertexOffsetOfPosition);
glVertexAttribPointer((GLuint)_openGL_state->textureCoordinatesAttribute, 2, GL_UNSIGNED_SHORT, GL_FALSE, vertexStride, (void *)kCRTVertexOffsetOfTexCoord);
glVertexAttribPointer((GLuint)_openGL_state->timestampAttribute, 4, GL_UNSIGNED_INT, GL_FALSE, vertexStride, (void *)kCRTVertexOffsetOfTimestamp);
glVertexAttribPointer((GLuint)_openGL_state->lateralAttribute, 1, GL_UNSIGNED_BYTE, GL_FALSE, vertexStride, (void *)kCRTVertexOffsetOfLateral);
}
void CRT::set_output_device(OutputDevice output_device)
{
_output_device = output_device;
}