demo.cpp

#include <windows.h>
#define seconds * 1e3
#define GLExt(a) a(wglGetProcAddress(#a))
#define native(t) __declspec(dllimport) t __stdcall


// ## FRAMEWORK SETTINGS ##
//~ #define USEWIN						// Use a window (not recommended)
#define MODERN_GLSL						// One stop shader compiling
#define REUSE							// Turn on aggressive register reuse (can save dozens of bytes)
#define RE_REG_POSITIVE edi				// Annotates a "big positive value" (e.g. hDC)
// ########################

// #### DEMO  SETTINGS ####
#define XRES    1366
#define YRES     768
#define RUNTIME  15 seconds
// ########################


// 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
*/


extern "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);
}

void entrypoint( void ) {
	const static PIXELFORMATDESCRIPTOR pfd = {0,0,PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER};

#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);
#ifdef REUSE
	__asm {
		push RE_REG_POSITIVE;
		push 0;
		call SetCursorPos;
	}
#else
	SetCursorPos(0,YRES);
#endif
#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();

loop:
		char pflog[1024];
		const auto elapsed = GetTickCount() - starttime;

		wsprintf(pflog, "void main(void) {"
			"float time = %d. / 1000.;"
			"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.;"
		"}", elapsed);

		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

#ifdef REUSE
		__asm {
			push RE_REG_POSITIVE;
			push RE_REG_POSITIVE;
			push -1;
			push -1;
			call glRects;
		}
#else
		glRects(-1,-1,1,1);
#endif

        SwapBuffers(hDC);

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

graceful:
    ExitProcess( 0 );
}