demo_beatsync.cpp

#define seconds * 1e3
#define bpm 60000 /
#define frames -1
#define GLExt(a) a(wglGetProcAddress(#a))
#define native(t) __declspec(dllimport) t __stdcall
#define MIDINote(hout, base, note, volume, channel) midiOutShortMsg(hout, 0x90 + ((base + note) * 0x100) + (volume * 0x10000) + channel)


// ## FRAMEWORK SETTINGS ##
//~ #define USEWIN						// Use a window (not recommended)
#define MODERN_GLSL						// One stop shader compiling
#define SOUND							// Midi?
// ########################

// ####### DEMO SETTINGS #######
#define XRES        1366
#define YRES         768
#define RUNTIME       15 seconds
#define SONGSPEED    bpm 120
#define BEAT_SUSTAIN  10 frames
// #############################


// Compile: cl /c /GS- /O2 /Ob1 /Oi /Os /FAs blah.cpp
/* Link:    crinkler.exe
			/OUT:".\demo.exe"
			opengl32.lib glu32.lib winmm.lib kernel32.lib user32.lib gdi32.lib
			winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib
			uuid.lib odbc32.lib odbccp32.lib msvcrt.lib libcmt.lib
			/SUBSYSTEM:WINDOWS
			/ENTRY:"entrypoint"
			/CRINKLER
			/HASHTRIES:8192
			/COMPMODE:SLOW
			/ORDERTRIES:32000
			/TINYHEADER
			/TINYIMPORT
			/UNALIGNCODE
			/REPORT:.\demo.html
			/SATURATE
			/UNSAFEIMPORT
			/LIBPATH:"C:\Program Files (x86)\Windows Kits\8.1\Lib\winv6.3\um\x86"
			/RANGE:opengl32
			.\blah.obj
*/


// Bootstrap your own windows.h. Using the stock one incurs 10+ bytes

extern "C" {
	struct BUTTER_PFDC { int a, b, c; };
	typedef void(__stdcall*glUseProgram)(int);
	typedef int(__stdcall*glCreateProgram)(void);
	typedef int(__stdcall*glCreateShader)(int);
	typedef void(__stdcall*glLinkProgram)(int);
	typedef void(__stdcall*glCompileShader)(int);
	typedef void(__stdcall*glAttachShader)(int,int);
	typedef void(__stdcall*glShaderSource)(unsigned shader, int count, const char** string, const int *length);
	typedef int(__stdcall*glCreateShaderProgramv)(int, int, const char**);
	native(void) glRects(short, short, short, short);
	native(int) GetDC(void*);
	native(int) GetAsyncKeyState(int);
	native(int) SetCursorPos(int, int);
	native(int) GetTickCount();
	native(int) wglGetProcAddress(const char*);
	native(int) wglMakeCurrent(int, int);
	native(int) ChoosePixelFormat(int, const BUTTER_PFDC*);
	native(int) SetPixelFormat(int, int, const BUTTER_PFDC*);
	native(int) wglCreateContext(int);
	native(void) SwapBuffers(int);
	native(void) ExitProcess(int);
	native(int) wsprintfA(char*, char*, ...);
	native(int) Beep(int,int);
	native(int) midiOutClose(int*);
	native(int) midiOutShortMsg(int, long);
	native(int) midiOutOpen(int*, int, int, int, int);
}

void entrypoint( void ) {
	const static BUTTER_PFDC pfd = {0,0,0x00000020|0x00000001};
#ifdef SOUND
	int hMidi = 0;
	midiOutClose(&hMidi);
	if(midiOutOpen(&hMidi, 0, 0, 0, 0)) goto graceful;

#endif

#ifdef USEWIN
    const auto hDC = GetDC(CreateWindow("edit", 0, WS_POPUP|WS_VISIBLE|WS_MAXIMIZE, 0,0,0,0,0,0,0,0));
	ShowCursor( 0 );
#else
	const auto hDC = GetDC(nullptr);
	SetCursorPos(0,YRES);
#endif

    SetPixelFormat(hDC, ChoosePixelFormat(hDC, &pfd), &pfd);
    wglMakeCurrent(hDC, wglCreateContext(hDC));

#ifndef MODERN_GLSL
    const auto p = GLExt(glCreateProgram)();
    const auto s = GLExt(glCreateShader)(0x8B30);
#endif
	const auto starttime = GetTickCount();
	auto beattime = 0;
	MIDINote(hMidi, 23, 0, 127, 15);
	int frame_sustain = 0;

loop:
		char pflog[1024];
		const auto elapsed = GetTickCount() - starttime;
		const int onbeat = elapsed - beattime > SONGSPEED;

		if(onbeat) {
			frame_sustain = 1;
			Beep(1e3, 10);
			beattime = elapsed;
		}

		if(frame_sustain && frame_sustain < BEAT_SUSTAIN)
			frame_sustain++;
		else
			frame_sustain = 0;

		wsprintfA(pflog, "void main(void) {"
			"float time = %d. / 1000.;"
			"float onbeat = %d.;"
			"float t = time, p;"
			"vec2 g = gl_FragCoord.xy, s = vec2(1366.,768.), u = (g+g-s)/s.y, ar = vec2(atan(u.x, u.y) * 3.18 + t*2., length(u)*3. + fract(t*.5)*4.);"
			"p = floor(ar.y)/5.;"
			"ar = abs(fract(ar)-.5);"
			"gl_FragColor = mix(vec4(1,.3,0,1), vec4(.3,.2,.5,1), vec4(fract((p)))) * .1/dot(ar,ar);"
			"gl_FragColor.a = 1.;"
			"if(onbeat > 0.) gl_FragColor += 1. / onbeat;"
		"}", elapsed, frame_sustain);

		const char *blorg = pflog;

#ifdef MODERN_GLSL
		GLExt(glUseProgram)(GLExt(glCreateShaderProgramv)(0x8B30, 1, &blorg));
#else
		GLExt(glShaderSource)(s, 1, &blorg, 0);
		GLExt(glCompileShader)(s);
		GLExt(glAttachShader)(p,s);
		GLExt(glLinkProgram)(p);
		GLExt(glUseProgram)(p);
#endif

		glRects(-1,-1,1,1);

        SwapBuffers(hDC);

		if(GetAsyncKeyState(27) || elapsed > RUNTIME) goto graceful;
	goto loop;

graceful:
    ExitProcess(
#ifdef SOUND
		midiOutClose(&hMidi)
#else
		0
#endif
	);
}