/*
 * Some tests for OpenGL functions
 *
 * Copyright (C) 2007 Roderick Colenbrander
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include <windows.h>
#include <wingdi.h>
#include "wine/test.h"

#define MAX_FORMATS 256
typedef void* HPBUFFERARB;

/* WGL_ARB_extensions_string */
static const char* (WINAPI *pwglGetExtensionsStringARB)(HDC);
static int (WINAPI *pwglReleasePbufferDCARB)(HPBUFFERARB, HDC);

/* WGL_ARB_make_current_read */
static BOOL (WINAPI *pwglMakeContextCurrentARB)(HDC hdraw, HDC hread, HGLRC hglrc);
static HDC (WINAPI *pwglGetCurrentReadDCARB)();

/* WGL_ARB_pixel_format */
#define WGL_COLOR_BITS_ARB 0x2014
#define WGL_RED_BITS_ARB   0x2015
#define WGL_GREEN_BITS_ARB 0x2017
#define WGL_BLUE_BITS_ARB  0x2019
#define WGL_ALPHA_BITS_ARB 0x201B
#define WGL_SUPPORT_GDI_ARB   0x200F
#define WGL_DOUBLE_BUFFER_ARB 0x2011

static BOOL (WINAPI *pwglChoosePixelFormatARB)(HDC, const int *, const FLOAT *, UINT, int *, UINT *);
static BOOL (WINAPI *pwglGetPixelFormatAttribivARB)(HDC, int, int, UINT, const int *, int *);

/* WGL_ARB_pbuffer */
#define WGL_DRAW_TO_PBUFFER_ARB 0x202D
static HPBUFFERARB* (WINAPI *pwglCreatePbufferARB)(HDC, int, int, int, const int *);
static HDC (WINAPI *pwglGetPbufferDCARB)(HPBUFFERARB);

static const char* wgl_extensions = NULL;

static void init_functions(void)
{
#define GET_PROC(func) \
    p ## func = (void*)wglGetProcAddress(#func); \
    if(!p ## func) \
      trace("wglGetProcAddress(%s) failed\n", #func);

    /* WGL_ARB_extensions_string */
    GET_PROC(wglGetExtensionsStringARB)

    /* WGL_ARB_make_current_read */
    GET_PROC(wglMakeContextCurrentARB);
    GET_PROC(wglGetCurrentReadDCARB);

    /* WGL_ARB_pixel_format */
    GET_PROC(wglChoosePixelFormatARB)
    GET_PROC(wglGetPixelFormatAttribivARB)

    /* WGL_ARB_pbuffer */
    GET_PROC(wglCreatePbufferARB)
    GET_PROC(wglGetPbufferDCARB)
    GET_PROC(wglReleasePbufferDCARB)

#undef GET_PROC
}

static void test_pbuffers(HDC hdc)
{
    const int iAttribList[] = { WGL_DRAW_TO_PBUFFER_ARB, 1, /* Request pbuffer support */
                                0 };
    int iFormats[MAX_FORMATS];
    unsigned int nOnscreenFormats;
    unsigned int nFormats;
    int i, res;
    int iPixelFormat = 0;

    nOnscreenFormats = DescribePixelFormat(hdc, 0, 0, NULL);

    /* When you want to render to a pbuffer you need to call wglGetPbufferDCARB which
     * returns a 'magic' HDC which you can then pass to wglMakeCurrent to switch rendering
     * to the pbuffer. Below some tests are performed on what happens if you use standard WGL calls
     * on this 'magic' HDC for both a pixelformat that support onscreen and offscreen rendering
     * and a pixelformat that's only available for offscreen rendering (this means that only
     * wglChoosePixelFormatARB and friends know about the format.
     *
     * The first thing we need are pixelformats with pbuffer capabilites.
     */
    res = pwglChoosePixelFormatARB(hdc, iAttribList, NULL, MAX_FORMATS, iFormats, &nFormats);
    if(res <= 0)
    {
        skip("No pbuffer compatible formats found while WGL_ARB_pbuffer is supported\n");
        return;
    }
    trace("nOnscreenFormats: %d\n", nOnscreenFormats);
    trace("Total number of pbuffer capable pixelformats: %d\n", nFormats);

    /* Try to select an onscreen pixelformat out of the list */
    for(i=0; i < nFormats; i++)
    {
        /* Check if the format is onscreen, if it is choose it */
        if(iFormats[i] <= nOnscreenFormats)
        {
            iPixelFormat = iFormats[i];
            trace("Selected iPixelFormat=%d\n", iPixelFormat);
            break;
        }
    }

    /* A video driver supports a large number of onscreen and offscreen pixelformats.
     * The traditional WGL calls only see a subset of the whole pixelformat list. First
     * of all they only see the onscreen formats (the offscreen formats are at the end of the
     * pixelformat list) and second extended pixelformat capabilities are hidden from the
     * standard WGL calls. Only functions that depend on WGL_ARB_pixel_format can see them.
     *
     * Below we check if the pixelformat is also supported onscreen.
     */
    if(iPixelFormat != 0)
    {
        HDC pbuffer_hdc;
        HPBUFFERARB pbuffer = pwglCreatePbufferARB(hdc, iPixelFormat, 640 /* width */, 480 /* height */, NULL);
        if(!pbuffer)
            skip("Pbuffer creation failed!\n");

        /* Test the pixelformat returned by GetPixelFormat on a pbuffer as the behavior is not clear */
        pbuffer_hdc = pwglGetPbufferDCARB(pbuffer);
        res = GetPixelFormat(pbuffer_hdc);
        ok(res == iPixelFormat, "Unexpected iPixelFormat=%d returned by GetPixelFormat for format %d\n", res, iPixelFormat);
        trace("iPixelFormat returned by GetPixelFormat: %d\n", res);
        trace("PixelFormat from wglChoosePixelFormatARB: %d\n", iPixelFormat);

        pwglReleasePbufferDCARB(pbuffer, hdc);
    }
    else skip("Pbuffer test for onscreen pixelformat skipped as no onscreen format with pbuffer capabilities have been found\n");

    /* Search for a real offscreen format */
    for(i=0, iPixelFormat=0; i<nFormats; i++)
    {
        if(iFormats[i] > nOnscreenFormats)
        {
            iPixelFormat = iFormats[i];
            trace("Selected iPixelFormat: %d\n", iPixelFormat);
            break;
        }
    }

    if(iPixelFormat != 0)
    {
        HDC pbuffer_hdc;
        HPBUFFERARB pbuffer = pwglCreatePbufferARB(hdc, iPixelFormat, 640 /* width */, 480 /* height */, NULL);
        if(!pbuffer)
            skip("Pbuffer creation failed!\n");

        /* Test the pixelformat returned by GetPixelFormat on a pbuffer as the behavior is not clear */
        pbuffer_hdc = pwglGetPbufferDCARB(pbuffer);
        res = GetPixelFormat(pbuffer_hdc);

        ok(res == 1, "Unexpected iPixelFormat=%d (1 expected) returned by GetPixelFormat for offscreen format %d\n", res, iPixelFormat);
        trace("iPixelFormat returned by GetPixelFormat: %d\n", res);
        trace("PixelFormat from wglChoosePixelFormatARB: %d\n", iPixelFormat);
        pwglReleasePbufferDCARB(pbuffer, hdc);
    }
    else skip("Pbuffer test for offscreen pixelformat skipped as no offscreen-only format with pbuffer capabilities has been found\n");
}

static void test_setpixelformat(void)
{
    int res = 0;
    int pf;
    PIXELFORMATDESCRIPTOR pfd = {
        sizeof(PIXELFORMATDESCRIPTOR),
        1,                     /* version */
        PFD_DRAW_TO_WINDOW |
        PFD_SUPPORT_OPENGL |
        PFD_DOUBLEBUFFER,
        PFD_TYPE_RGBA,
        24,                    /* 24-bit color depth */
        0, 0, 0, 0, 0, 0,      /* color bits */
        0,                     /* alpha buffer */
        0,                     /* shift bit */
        0,                     /* accumulation buffer */
        0, 0, 0, 0,            /* accum bits */
        32,                    /* z-buffer */
        0,                     /* stencil buffer */
        0,                     /* auxiliary buffer */
        PFD_MAIN_PLANE,        /* main layer */
        0,                     /* reserved */
        0, 0, 0                /* layer masks */
    };

    HDC hdc = GetDC(0);
    ok(hdc != 0, "GetDC(0) failed!\n");

    /* This should pass even on the main device context */
    pf = ChoosePixelFormat(hdc, &pfd);
    ok(pf != 0, "ChoosePixelFormat failed on main device context\n");

    /* SetPixelFormat on the main device context 'X root window' should fail */
    res = SetPixelFormat(hdc, pf, &pfd);
    ok(res == 0, "SetPixelFormat on main device context should fail\n");
}

static void test_colorbits(HDC hdc)
{
    const int iAttribList[] = { WGL_COLOR_BITS_ARB, WGL_RED_BITS_ARB, WGL_GREEN_BITS_ARB,
                                WGL_BLUE_BITS_ARB, WGL_ALPHA_BITS_ARB };
    int iAttribRet[sizeof(iAttribList)/sizeof(iAttribList[0])];
    const int iAttribs[] = { WGL_ALPHA_BITS_ARB, 1, 0 };
    unsigned int nFormats;
    int res;
    int iPixelFormat = 0;

    /* We need a pixel format with at least one bit of alpha */
    res = pwglChoosePixelFormatARB(hdc, iAttribs, NULL, 1, &iPixelFormat, &nFormats);
    if(res == FALSE || nFormats == 0)
    {
        skip("No suitable pixel formats found\n");
        return;
    }

    res = pwglGetPixelFormatAttribivARB(hdc, iPixelFormat, 0,
              sizeof(iAttribList)/sizeof(iAttribList[0]), iAttribList, iAttribRet);
    if(res == FALSE)
    {
        skip("wglGetPixelFormatAttribivARB failed\n");
        return;
    }
    iAttribRet[1] += iAttribRet[2]+iAttribRet[3]+iAttribRet[4];
    ok(iAttribRet[0] == iAttribRet[1], "WGL_COLOR_BITS_ARB (%d) does not equal R+G+B+A (%d)!\n",
                                       iAttribRet[0], iAttribRet[1]);
}

static void test_gdi_dbuf(HDC hdc)
{
    const int iAttribList[] = { WGL_SUPPORT_GDI_ARB, WGL_DOUBLE_BUFFER_ARB };
    int iAttribRet[sizeof(iAttribList)/sizeof(iAttribList[0])];
    unsigned int nFormats;
    int iPixelFormat;
    int res;

    nFormats = DescribePixelFormat(hdc, 0, 0, NULL);
    for(iPixelFormat = 1;iPixelFormat <= nFormats;iPixelFormat++)
    {
        res = pwglGetPixelFormatAttribivARB(hdc, iPixelFormat, 0,
                  sizeof(iAttribList)/sizeof(iAttribList[0]), iAttribList,
                  iAttribRet);
        ok(res!=FALSE, "wglGetPixelFormatAttribivARB failed for pixel format %d\n", iPixelFormat);
        if(res == FALSE)
            continue;

        ok(!(iAttribRet[0] && iAttribRet[1]), "GDI support and double buffering on pixel format %d\n", iPixelFormat);
    }
}

static void test_make_current_read(HDC hdc)
{
    int res;
    HDC hread;
    HGLRC hglrc = wglCreateContext(hdc);

    if(!hglrc)
    {
        skip("wglCreateContext failed!\n");
        return;
    }

    res = wglMakeCurrent(hdc, hglrc);
    if(!res)
    {
        skip("wglMakeCurrent failed!\n");
        return;
    }

    /* Test what wglGetCurrentReadDCARB does for wglMakeCurrent as the spec doesn't mention it */
    hread = pwglGetCurrentReadDCARB();
    trace("hread %p, hdc %p\n", hread, hdc);
    ok(hread == hdc, "wglGetCurrentReadDCARB failed for standard wglMakeCurrent\n");

    pwglMakeContextCurrentARB(hdc, hdc, hglrc);
    hread = pwglGetCurrentReadDCARB();
    ok(hread == hdc, "wglGetCurrentReadDCARB failed for wglMakeContextCurrent\n");
}

static void test_dc(HWND hwnd, HDC hdc)
{
    int pf1, pf2;
    HDC hdc2;

    /* Get another DC and make sure it has the same pixel format */
    hdc2 = GetDC(hwnd);
    if(hdc != hdc2)
    {
        pf1 = GetPixelFormat(hdc);
        pf2 = GetPixelFormat(hdc2);
        ok(pf1 == pf2, "Second DC does not have the same format (%d != %d)\n", pf1, pf2);
    }
    else
        skip("Could not get a different DC for the window\n");

    if(hdc2)
    {
        ReleaseDC(hwnd, hdc2);
        hdc2 = NULL;
    }
}

START_TEST(opengl)
{
    HWND hwnd;
    PIXELFORMATDESCRIPTOR pfd = {
        sizeof(PIXELFORMATDESCRIPTOR),
        1,                     /* version */
        PFD_DRAW_TO_WINDOW |
        PFD_SUPPORT_OPENGL |
        PFD_DOUBLEBUFFER,
        PFD_TYPE_RGBA,
        24,                    /* 24-bit color depth */
        0, 0, 0, 0, 0, 0,      /* color bits */
        0,                     /* alpha buffer */
        0,                     /* shift bit */
        0,                     /* accumulation buffer */
        0, 0, 0, 0,            /* accum bits */
        32,                    /* z-buffer */
        0,                     /* stencil buffer */
        0,                     /* auxiliary buffer */
        PFD_MAIN_PLANE,        /* main layer */
        0,                     /* reserved */
        0, 0, 0                /* layer masks */
    };

    hwnd = CreateWindow("static", "Title", WS_OVERLAPPEDWINDOW,
                        10, 10, 200, 200, NULL, NULL, NULL, NULL);
    ok(hwnd != NULL, "err: %d\n", GetLastError());
    if (hwnd)
    {
        HDC hdc;
        int iPixelFormat, res;
        HGLRC hglrc;
        ShowWindow(hwnd, SW_SHOW);

        hdc = GetDC(hwnd);

        iPixelFormat = ChoosePixelFormat(hdc, &pfd);
        ok(iPixelFormat > 0, "No pixelformat found!\n"); /* This should never happen as ChoosePixelFormat always returns a closest match */

        res = SetPixelFormat(hdc, iPixelFormat, &pfd);
        ok(res, "SetPixelformat failed: %x\n", GetLastError());

        test_dc(hwnd, hdc);

        hglrc = wglCreateContext(hdc);
        res = wglMakeCurrent(hdc, hglrc);
        ok(res, "wglMakeCurrent failed!\n");
        init_functions();

        test_setpixelformat();
        test_colorbits(hdc);
        test_gdi_dbuf(hdc);

        wgl_extensions = pwglGetExtensionsStringARB(hdc);
        if(wgl_extensions == NULL) skip("Skipping opengl32 tests because this OpenGL implementation doesn't support WGL extensions!\n");

        if(strstr(wgl_extensions, "WGL_ARB_make_current_read"))
            test_make_current_read(hdc);
        else
            trace("WGL_ARB_make_current_read not supported, skipping test\n");

        if(strstr(wgl_extensions, "WGL_ARB_pbuffer"))
            test_pbuffers(hdc);
        else
            trace("WGL_ARB_pbuffer not supported, skipping pbuffer test\n");

        DestroyWindow(hwnd);
    }
}