CLK/OSBindings/Mac/Clock Signal/Atari2600.mm

//
//  Atari2600.m
//  ElectrEm
//
//  Created by Thomas Harte on 14/07/2015.
//  Copyright © 2015 Thomas Harte. All rights reserved.
//

#import "Atari2600.h"
#import "Atari2600.hpp"
#import <OpenGL/gl3.h>

const char *vertexShader =
	"#version 150\n"
	"\n"
	"in vec2 position;\n"
	"\n"
	"out vec4 colour;\n"
	"\n"
	"void main (void)\n"
	"{\n"
		"colour = vec4(position, 0.0, 1.0);\n"
		"gl_Position = vec4(position, 0.0, 1.0);\n"
	"}\n";

const char *fragmentShader =
	"#version 150\n"
	"\n"
	"in vec4 colour;\n"
	"out vec4 fragColour;\n"
	"\n"
	"void main(void)\n"
	"{\n"
		"fragColour = colour;\n"
	"}\n";

@interface CSAtari2600 (Callbacks)
- (void)crtDidEndFrame:(Outputs::CRTFrame *)frame;
@end

struct Atari2600CRTDelegate: public Outputs::CRT::CRTDelegate {
	CSAtari2600 *atari;
	void crt_did_end_frame(Outputs::CRT *crt, Outputs::CRTFrame *frame) { [atari crtDidEndFrame:frame]; }
};

@implementation CSAtari2600 {
	Atari2600::Machine _atari2600;
	Atari2600CRTDelegate _crtDelegate;

	dispatch_queue_t _serialDispatchQueue;
	Outputs::CRTFrame *_queuedFrame;

	GLuint _vertexShader, _fragmentShader;
	GLuint _shaderProgram;

	GLuint _arrayBuffer, _vertexArray;
}

- (void)crtDidEndFrame:(Outputs::CRTFrame *)frame {

	dispatch_async(dispatch_get_main_queue(), ^{
		if(_queuedFrame) {
			dispatch_async(_serialDispatchQueue, ^{
				_atari2600.get_crt()->return_frame();
			});
		}
		_queuedFrame = frame;

		[self.delegate atari2600NeedsRedraw:self];
	});
}

- (GLuint)compileShader:(const char *)source type:(GLenum)type
{
	GLuint shader = glCreateShader(type);
	glShaderSource(shader, 1, &source, NULL);
	glCompileShader(shader);
	return shader;
}

- (void)draw {

	if(!_shaderProgram)
	{
		_shaderProgram = glCreateProgram();
		_vertexShader = [self compileShader:vertexShader type:GL_VERTEX_SHADER];
		_fragmentShader = [self compileShader:fragmentShader type:GL_FRAGMENT_SHADER];

		glAttachShader(_shaderProgram, _vertexShader);
		glAttachShader(_shaderProgram, _fragmentShader);
		glLinkProgram(_shaderProgram);

		glGenVertexArrays(1, &_vertexArray);
		glBindVertexArray(_vertexArray);
		glGenBuffers(1, &_arrayBuffer);
		glBindBuffer(GL_ARRAY_BUFFER, _arrayBuffer);

		GLfloat vertices[] = {
			0.0f, 0.0f,
			0.5f, 0.0f,
			0.5f, 0.6f,
			0.0f, 0.5f
		};

		glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	}

	if(_queuedFrame)
	{
		glClearColor(1.0, 0.0, 0.0, 1.0);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(_shaderProgram);

		GLint position = glGetAttribLocation(_shaderProgram, "position");

		glEnableVertexAttribArray(position);
		glVertexAttribPointer(position, 2, GL_FLOAT, GL_FALSE, 0, (void *)0);

		glDrawArrays(GL_LINES, 0, 4);

/*		printf("\n\n===\n\n");
		int c = 0;
		for(int run = 0; run < _queuedFrame->number_of_runs; run++)
		{
			char character = ' ';
			switch(_queuedFrame->runs[run].type)
			{
				case Outputs::CRTRun::Type::Sync:	character = '<'; break;
				case Outputs::CRTRun::Type::Level:	character = '_'; break;
				case Outputs::CRTRun::Type::Data:	character = '-'; break;
				case Outputs::CRTRun::Type::Blank:	character = ' '; break;
			}

			if(_queuedFrame->runs[run].start_point.dst_x < 1.0 / 224.0)
			{
				printf("\n[%0.2f]: ", _queuedFrame->runs[run].start_point.dst_y);
				c++;
			}

			printf("(%0.2f): ", _queuedFrame->runs[run].start_point.dst_x);
			float length = fabsf(_queuedFrame->runs[run].end_point.dst_x - _queuedFrame->runs[run].start_point.dst_x);
			int iLength = (int)(length * 64.0);
			for(int c = 0; c < iLength; c++)
			{
				putc(character, stdout);
			}
		}

		printf("\n\n[%d]\n\n", c);*/
	}
}

- (void)runForNumberOfCycles:(int)cycles {
	dispatch_async(_serialDispatchQueue, ^{
		_atari2600.run_for_cycles(cycles);
	});
}

- (void)setROM:(NSData *)rom {
	dispatch_async(_serialDispatchQueue, ^{
		_atari2600.set_rom(rom.length, (const uint8_t *)rom.bytes);
	});
}

- (instancetype)init {
	self = [super init];

	if (self) {
		_crtDelegate.atari = self;
		_atari2600.get_crt()->set_delegate(&_crtDelegate);
		_serialDispatchQueue = dispatch_queue_create("Atari 2600 queue", DISPATCH_QUEUE_SERIAL);
	}

	return self;
}

@end