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CLK/Outputs/CRT/CRTOpenGL.cpp
2016-02-05 22:47:12 -05:00

339 lines
12 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>
// TODO: figure out correct include paths for other platforms.
#include <OpenGL/OpenGL.h>
#include <OpenGL/gl3.h>
using namespace Outputs;
struct CRT::OpenGLState {
GLuint vertexShader, fragmentShader;
GLuint shaderProgram;
GLuint arrayBuffer, vertexArray;
GLint positionAttribute;
GLint textureCoordinatesAttribute;
GLint lateralAttribute;
GLint textureSizeUniform, windowSizeUniform;
GLint boundsOriginUniform, boundsSizeUniform;
GLint alphaUniform;
GLuint textureName, shadowMaskTextureName;
CRTSize textureSize;
GLuint compile_shader(const char *source, GLenum type)
{
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &source, NULL);
glCompileShader(shader);
#if defined(DEBUG)
GLint isCompiled = 0;
glGetShaderiv(shader, GL_COMPILE_STATUS, &isCompiled);
if(isCompiled == GL_FALSE)
{
GLint logLength;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &logLength);
if (logLength > 0) {
GLchar *log = (GLchar *)malloc((size_t)logLength);
glGetShaderInfoLog(shader, logLength, &logLength, log);
printf("Compile log:\n%s\n", log);
free(log);
}
}
#endif
return shader;
}
};
static GLenum formatForDepth(unsigned int 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;
_current_frame = _last_drawn_frame = nullptr;
_composite_shader = _rgb_shader = nullptr;
}
void CRT::destruct_openGL()
{
delete (OpenGLState *)_openGL_state;
if(_composite_shader) free(_composite_shader);
if(_rgb_shader) free(_rgb_shader);
}
void CRT::draw_frame(int output_width, int output_height, bool only_if_dirty)
{
_current_frame_mutex->lock();
if(!_current_frame && !only_if_dirty)
{
glClear(GL_COLOR_BUFFER_BIT);
}
if(_current_frame && (_current_frame != _last_drawn_frame || !only_if_dirty))
{
glClear(GL_COLOR_BUFFER_BIT);
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);
glGenVertexArrays(1, &_openGL_state->vertexArray);
glBindVertexArray(_openGL_state->vertexArray);
glGenBuffers(1, &_openGL_state->arrayBuffer);
glBindBuffer(GL_ARRAY_BUFFER, _openGL_state->arrayBuffer);
prepare_shader();
}
push_size_uniforms(output_width, output_height);
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)(_current_frame->number_of_vertices * _current_frame->size_per_vertex), _current_frame->vertices, GL_DYNAMIC_DRAW);
glBindTexture(GL_TEXTURE_2D, _openGL_state->textureName);
if(_openGL_state->textureSize.width != _current_frame->size.width || _openGL_state->textureSize.height != _current_frame->size.height)
{
GLenum format = formatForDepth(_current_frame->buffers[0].depth);
glTexImage2D(GL_TEXTURE_2D, 0, (GLint)format, _current_frame->size.width, _current_frame->size.height, 0, format, GL_UNSIGNED_BYTE, _current_frame->buffers[0].data);
_openGL_state->textureSize = _current_frame->size;
if(_openGL_state->textureSizeUniform >= 0)
glUniform2f(_openGL_state->textureSizeUniform, _current_frame->size.width, _current_frame->size.height);
}
else
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, _current_frame->size.width, _current_frame->dirty_size.height, formatForDepth(_current_frame->buffers[0].depth), GL_UNSIGNED_BYTE, _current_frame->buffers[0].data);
glDrawArrays(GL_TRIANGLES, 0, (GLsizei)_current_frame->number_of_vertices);
}
_current_frame_mutex->unlock();
}
void CRT::set_openGL_context_will_change(bool should_delete_resources)
{
}
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 = 1.0;//(viewSize.x / viewSize.y) / (4.0 / 3.0);
// _aspectRatioCorrectedBounds = _frameBounds;
// CGFloat bonusWidth = (outputAspectRatioMultiplier - 1.0f) * _frameBounds.size.width;
// _aspectRatioCorrectedBounds.origin.x -= bonusWidth * 0.5f * _aspectRatioCorrectedBounds.size.width;
// _aspectRatioCorrectedBounds.size.width *= outputAspectRatioMultiplier;
if(_openGL_state->boundsOriginUniform >= 0)
glUniform2f(_openGL_state->boundsOriginUniform, 0.0, 0.0); //(GLfloat)_aspectRatioCorrectedBounds.origin.x, (GLfloat)_aspectRatioCorrectedBounds.origin.y);
if(_openGL_state->boundsSizeUniform >= 0)
glUniform2f(_openGL_state->boundsSizeUniform, 1.0, 1.0);//(GLfloat)_aspectRatioCorrectedBounds.size.width, (GLfloat)_aspectRatioCorrectedBounds.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;"
"uniform vec2 boundsOrigin;"
"uniform vec2 boundsSize;"
"out float lateralVarying;"
"out vec2 shadowMaskCoordinates;"
"uniform vec2 textureSize;"
"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);\n"
"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 vec2 shadowMaskCoordinates;"
"out vec4 fragColour;"
"uniform sampler2D texID;"
"uniform sampler2D shadowMaskTexID;"
"uniform float alpha;"
"in vec2 srcCoordinatesVarying;"
"in float phase;\n"
"%s\n"
"void main(void)"
"{"
"fragColour = vec4(rgb_sample(srcCoordinatesVarying).rgb, 1.0);"
"}"
, _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 = glCreateProgram();
_openGL_state->vertexShader = _openGL_state->compile_shader(vertex_shader, GL_VERTEX_SHADER);
_openGL_state->fragmentShader = _openGL_state->compile_shader(fragment_shader, GL_FRAGMENT_SHADER);
delete vertex_shader;
delete fragment_shader;
glAttachShader(_openGL_state->shaderProgram, _openGL_state->vertexShader);
glAttachShader(_openGL_state->shaderProgram, _openGL_state->fragmentShader);
glLinkProgram(_openGL_state->shaderProgram);
glUseProgram(_openGL_state->shaderProgram);
_openGL_state->positionAttribute = glGetAttribLocation(_openGL_state->shaderProgram, "position");
_openGL_state->textureCoordinatesAttribute = glGetAttribLocation(_openGL_state->shaderProgram, "srcCoordinates");
_openGL_state->lateralAttribute = glGetAttribLocation(_openGL_state->shaderProgram, "lateral");
_openGL_state->alphaUniform = glGetUniformLocation(_openGL_state->shaderProgram, "alpha");
_openGL_state->textureSizeUniform = glGetUniformLocation(_openGL_state->shaderProgram, "textureSize");
_openGL_state->windowSizeUniform = glGetUniformLocation(_openGL_state->shaderProgram, "windowSize");
_openGL_state->boundsSizeUniform = glGetUniformLocation(_openGL_state->shaderProgram, "boundsSize");
_openGL_state->boundsOriginUniform = glGetUniformLocation(_openGL_state->shaderProgram, "boundsOrigin");
GLint texIDUniform = glGetUniformLocation(_openGL_state->shaderProgram, "texID");
GLint shadowMaskTexIDUniform = glGetUniformLocation(_openGL_state->shaderProgram, "shadowMaskTexID");
// [self pushSizeUniforms];
glUniform1i(texIDUniform, 0);
glUniform1i(shadowMaskTexIDUniform, 1);
glEnableVertexAttribArray((GLuint)_openGL_state->positionAttribute);
glEnableVertexAttribArray((GLuint)_openGL_state->textureCoordinatesAttribute);
glEnableVertexAttribArray((GLuint)_openGL_state->lateralAttribute);
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->lateralAttribute, 1, GL_UNSIGNED_BYTE, GL_FALSE, vertexStride, (void *)kCRTVertexOffsetOfLateral);
}