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****************************************************************************/

#include <qglpixelbuffer.h>

#include <qgl.h>

#include <private/qgl_p.h>

#include <private/qglpixelbuffer_p.h>

#include <qimage.h>

#include <qdebug.h>

QT_BEGIN_NAMESPACE

/* WGL_WGLEXT_PROTOTYPES */

typedef const char * (WINAPI * PFNWGLGETEXTENSIONSSTRINGARBPROC) (HDC hdc);

typedef HPBUFFERARB (WINAPI * PFNWGLCREATEPBUFFERARBPROC) (HDC hDC, int iPixelFormat, int iWidth, int iHeight, const int *piAttribList);

typedef HDC (WINAPI * PFNWGLGETPBUFFERDCARBPROC) (HPBUFFERARB hPbuffer);

typedef int (WINAPI * PFNWGLRELEASEPBUFFERDCARBPROC) (HPBUFFERARB hPbuffer, HDC hDC);

typedef BOOL (WINAPI * PFNWGLDESTROYPBUFFERARBPROC) (HPBUFFERARB hPbuffer);

typedef BOOL (WINAPI * PFNWGLQUERYPBUFFERARBPROC) (HPBUFFERARB hPbuffer, int iAttribute, int *piValue);

typedef BOOL (WINAPI * PFNWGLGETPIXELFORMATATTRIBIVARBPROC) (HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, const int *piAttributes, int *piValues);

typedef BOOL (WINAPI * PFNWGLGETPIXELFORMATATTRIBFVARBPROC) (HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, const int *piAttributes, FLOAT *pfValues);

typedef BOOL (WINAPI * PFNWGLCHOOSEPIXELFORMATARBPROC) (HDC hdc, const int *piAttribIList, const FLOAT *pfAttribFList, UINT nMaxFormats, int *piFormats, UINT *nNumFormats);

typedef BOOL (WINAPI * PFNWGLBINDTEXIMAGEARBPROC) (HPBUFFERARB hPbuffer, int iBuffer);

typedef BOOL (WINAPI * PFNWGLRELEASETEXIMAGEARBPROC) (HPBUFFERARB hPbuffer, int iBuffer);

typedef BOOL (WINAPI * PFNWGLSETPBUFFERATTRIBARBPROC) (HPBUFFERARB hPbuffer, const int * piAttribList);

#ifndef WGL_ARB_pbuffer

#define WGL_DRAW_TO_PBUFFER_ARB        0x202D

#define WGL_MAX_PBUFFER_PIXELS_ARB     0x202E

#define WGL_MAX_PBUFFER_WIDTH_ARB      0x202F

#define WGL_MAX_PBUFFER_HEIGHT_ARB     0x2030

#define WGL_PBUFFER_LARGEST_ARB        0x2033

#define WGL_PBUFFER_WIDTH_ARB          0x2034

#define WGL_PBUFFER_HEIGHT_ARB         0x2035

#define WGL_PBUFFER_LOST_ARB           0x2036

#endif

#ifndef WGL_ARB_pixel_format

#define WGL_NUMBER_PIXEL_FORMATS_ARB   0x2000

#define WGL_DRAW_TO_WINDOW_ARB         0x2001

#define WGL_DRAW_TO_BITMAP_ARB         0x2002

#define WGL_ACCELERATION_ARB           0x2003

#define WGL_NEED_PALETTE_ARB           0x2004

#define WGL_NEED_SYSTEM_PALETTE_ARB    0x2005

#define WGL_SWAP_LAYER_BUFFERS_ARB     0x2006

#define WGL_SWAP_METHOD_ARB            0x2007

#define WGL_NUMBER_OVERLAYS_ARB        0x2008

#define WGL_NUMBER_UNDERLAYS_ARB       0x2009

#define WGL_TRANSPARENT_ARB            0x200A

#define WGL_TRANSPARENT_RED_VALUE_ARB  0x2037

#define WGL_TRANSPARENT_GREEN_VALUE_ARB 0x2038

#define WGL_TRANSPARENT_BLUE_VALUE_ARB 0x2039

#define WGL_TRANSPARENT_ALPHA_VALUE_ARB 0x203A

#define WGL_TRANSPARENT_INDEX_VALUE_ARB 0x203B

#define WGL_SHARE_DEPTH_ARB            0x200C

#define WGL_SHARE_STENCIL_ARB          0x200D

#define WGL_SHARE_ACCUM_ARB            0x200E

#define WGL_SUPPORT_GDI_ARB            0x200F

#define WGL_SUPPORT_OPENGL_ARB         0x2010

#define WGL_DOUBLE_BUFFER_ARB          0x2011

#define WGL_STEREO_ARB                 0x2012

#define WGL_PIXEL_TYPE_ARB             0x2013

#define WGL_COLOR_BITS_ARB             0x2014

#define WGL_RED_BITS_ARB               0x2015

#define WGL_RED_SHIFT_ARB              0x2016

#define WGL_GREEN_BITS_ARB             0x2017

#define WGL_GREEN_SHIFT_ARB            0x2018

#define WGL_BLUE_BITS_ARB              0x2019

#define WGL_BLUE_SHIFT_ARB             0x201A

#define WGL_ALPHA_BITS_ARB             0x201B

#define WGL_ALPHA_SHIFT_ARB            0x201C

#define WGL_ACCUM_BITS_ARB             0x201D

#define WGL_ACCUM_RED_BITS_ARB         0x201E

#define WGL_ACCUM_GREEN_BITS_ARB       0x201F

#define WGL_ACCUM_BLUE_BITS_ARB        0x2020

#define WGL_ACCUM_ALPHA_BITS_ARB       0x2021

#define WGL_DEPTH_BITS_ARB             0x2022

#define WGL_STENCIL_BITS_ARB           0x2023

#define WGL_AUX_BUFFERS_ARB            0x2024

#define WGL_NO_ACCELERATION_ARB        0x2025

#define WGL_GENERIC_ACCELERATION_ARB   0x2026

#define WGL_FULL_ACCELERATION_ARB      0x2027

#define WGL_SWAP_EXCHANGE_ARB          0x2028

#define WGL_SWAP_COPY_ARB              0x2029

#define WGL_SWAP_UNDEFINED_ARB         0x202A

#define WGL_TYPE_RGBA_ARB              0x202B

#define WGL_TYPE_COLORINDEX_ARB        0x202C

#endif

#ifndef WGL_ARB_render_texture

#define WGL_BIND_TO_TEXTURE_RGB_ARB        0x2070

#define WGL_BIND_TO_TEXTURE_RGBA_ARB       0x2071

#define WGL_TEXTURE_FORMAT_ARB             0x2072

#define WGL_TEXTURE_TARGET_ARB             0x2073

#define WGL_MIPMAP_TEXTURE_ARB             0x2074

#define WGL_TEXTURE_RGB_ARB                0x2075

#define WGL_TEXTURE_RGBA_ARB               0x2076

#define WGL_NO_TEXTURE_ARB                 0x2077

#define WGL_TEXTURE_CUBE_MAP_ARB           0x2078

#define WGL_TEXTURE_1D_ARB                 0x2079

#define WGL_TEXTURE_2D_ARB                 0x207A

#define WGL_MIPMAP_LEVEL_ARB               0x207B

#define WGL_CUBE_MAP_FACE_ARB              0x207C

#define WGL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB 0x207D

#define WGL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB 0x207E

#define WGL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB 0x207F

#define WGL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB 0x2080

#define WGL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB 0x2081

#define WGL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB 0x2082

#define WGL_FRONT_LEFT_ARB                 0x2083

#define WGL_FRONT_RIGHT_ARB                0x2084

#define WGL_BACK_LEFT_ARB                  0x2085

#define WGL_BACK_RIGHT_ARB                 0x2086

#define WGL_AUX0_ARB                       0x2087

#define WGL_AUX1_ARB                       0x2088

#define WGL_AUX2_ARB                       0x2089

#define WGL_AUX3_ARB                       0x208A

#define WGL_AUX4_ARB                       0x208B

#define WGL_AUX5_ARB                       0x208C

#define WGL_AUX6_ARB                       0x208D

#define WGL_AUX7_ARB                       0x208E

#define WGL_AUX8_ARB                       0x208F

#define WGL_AUX9_ARB                       0x2090

#endif

#ifndef WGL_FLOAT_COMPONENTS_NV

#define WGL_FLOAT_COMPONENTS_NV        0x20B0

#endif

QGLFormat pfiToQGLFormat(HDC hdc, int pfi);

static void qt_format_to_attrib_list(bool has_render_texture, const QGLFormat &f, int attribs[])

{

    int i = 0;

    attribs[i++] = WGL_SUPPORT_OPENGL_ARB;

    attribs[i++] = TRUE;

    attribs[i++] = WGL_DRAW_TO_PBUFFER_ARB;

    attribs[i++] = TRUE;

    if (has_render_texture) {

        attribs[i++] = WGL_BIND_TO_TEXTURE_RGBA_ARB;

        attribs[i++] = TRUE;

    }

    attribs[i++] = WGL_COLOR_BITS_ARB;

    attribs[i++] = 32;

    attribs[i++] = WGL_DOUBLE_BUFFER_ARB;

    attribs[i++] = FALSE;

    if (f.stereo()) {

        attribs[i++] = WGL_STEREO_ARB;

        attribs[i++] = TRUE;

    }

    if (f.depth()) {

        attribs[i++] = WGL_DEPTH_BITS_ARB;

        attribs[i++] = f.depthBufferSize() == -1 ? 24 : f.depthBufferSize();

    }

    if (f.redBufferSize() != -1) {

        attribs[i++] = WGL_RED_BITS_ARB;

        attribs[i++] = f.redBufferSize();

    }

    if (f.greenBufferSize() != -1) {

        attribs[i++] = WGL_GREEN_BITS_ARB;

        attribs[i++] = f.greenBufferSize();

    }

    if (f.blueBufferSize() != -1) {

        attribs[i++] = WGL_BLUE_BITS_ARB;

        attribs[i++] = f.blueBufferSize();

    }

    if (f.alpha()) {

        attribs[i++] = WGL_ALPHA_BITS_ARB;

        attribs[i++] = f.alphaBufferSize() == -1 ? 8 : f.alphaBufferSize();

    }

    if (f.accum()) {

        attribs[i++] = WGL_ACCUM_BITS_ARB;

        attribs[i++] = f.accumBufferSize() == -1 ? 16 : f.accumBufferSize();

    }

    if (f.stencil()) {

        attribs[i++] = WGL_STENCIL_BITS_ARB;

        attribs[i++] = f.stencilBufferSize() == -1 ? 8 : f.stencilBufferSize();

    }

    if ((f.redBufferSize() > 8 || f.greenBufferSize() > 8

         || f.blueBufferSize() > 8 || f.alphaBufferSize() > 8)

        && (QGLExtensions::glExtensions & QGLExtensions::NVFloatBuffer))

    {

        attribs[i++] = WGL_FLOAT_COMPONENTS_NV;

        attribs[i++] = TRUE;

    }

    // sample buffers doesn't work in conjunction with the render_texture extension

    // so igonre that for now

    // if (f.sampleBuffers()) {

    //     attribs[i++] = WGL_SAMPLE_BUFFERS_ARB;

    //     attribs[i++] = 1;

    //     attribs[i++] = WGL_SAMPLES_ARB;

    //     attribs[i++] = f.samples() == -1 ? 16 : f.samples();

    // }

    attribs[i] = 0;

}

bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)

{

    QGLWidget dmy;

    dmy.makeCurrent(); // needed for wglGetProcAddress() to succeed

    PFNWGLCREATEPBUFFERARBPROC wglCreatePbufferARB =

        (PFNWGLCREATEPBUFFERARBPROC) wglGetProcAddress("wglCreatePbufferARB");

    PFNWGLGETPBUFFERDCARBPROC wglGetPbufferDCARB =

        (PFNWGLGETPBUFFERDCARBPROC) wglGetProcAddress("wglGetPbufferDCARB");

    PFNWGLQUERYPBUFFERARBPROC wglQueryPbufferARB =

        (PFNWGLQUERYPBUFFERARBPROC) wglGetProcAddress("wglQueryPbufferARB");

    PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormatARB =

        (PFNWGLCHOOSEPIXELFORMATARBPROC) wglGetProcAddress("wglChoosePixelFormatARB");

    if (!wglCreatePbufferARB) // assumes that if one can be resolved, all of them can

        return false;

    dc = GetDC(dmy.winId());

    Q_ASSERT(dc);

    PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB =

        (PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");

    if (wglGetExtensionsStringARB) {

        QString extensions(QLatin1String(wglGetExtensionsStringARB(dc)));

        has_render_texture = extensions.contains(QLatin1String("WGL_ARB_render_texture"));

    }

    int attribs[40];

    qt_format_to_attrib_list(has_render_texture, f, attribs);

    // Find pbuffer capable pixel format.

    unsigned int num_formats = 0;

    int pixel_format;

    wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);

    // some GL implementations don't support pbuffers with accum

    // buffers, so try that before we give up

    if (num_formats == 0 && f.accum()) {

        QGLFormat tmp = f;

        tmp.setAccum(false);

        qt_format_to_attrib_list(has_render_texture, tmp, attribs);

        wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);

    }

    if (num_formats == 0) {

        qWarning("QGLPixelBuffer: Unable to find a pixel format with pbuffer  - giving up.");

        ReleaseDC(dmy.winId(), dc);

        return false;

    }

    format = pfiToQGLFormat(dc, pixel_format);

    // NB! The below ONLY works if the width/height are powers of 2.

    // Set some pBuffer attributes so that we can use this pBuffer as

    // a 2D RGBA texture target.

    int pb_attribs[] = {WGL_TEXTURE_FORMAT_ARB, WGL_TEXTURE_RGBA_ARB,

                        WGL_TEXTURE_TARGET_ARB, WGL_TEXTURE_2D_ARB, 0};

    pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(),

                               has_render_texture ? pb_attribs : 0);

    if(!pbuf) {

        // try again without the render_texture extension

        pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(), 0);

        has_render_texture = false;

        if (!pbuf) {

            qWarning("QGLPixelBuffer: Unable to create pbuffer [w=%d, h=%d] - giving up.", size.width(), size.height());

            ReleaseDC(dmy.winId(), dc);

            return false;

        }

    }

    ReleaseDC(dmy.winId(), dc);

    dc = wglGetPbufferDCARB(pbuf);

    ctx = wglCreateContext(dc);

    if (!dc || !ctx) {

        qWarning("QGLPixelBuffer: Unable to create pbuffer context - giving up.");

        return false;

    }

    HGLRC share_ctx = shareWidget ? shareWidget->d_func()->glcx->d_func()->rc : 0;

    if (share_ctx && !wglShareLists(share_ctx, ctx))

        qWarning("QGLPixelBuffer: Unable to share display lists - with share widget.");

    int width, height;

    wglQueryPbufferARB(pbuf, WGL_PBUFFER_WIDTH_ARB, &width);

    wglQueryPbufferARB(pbuf, WGL_PBUFFER_HEIGHT_ARB, &height);

    return true;

}

bool QGLPixelBufferPrivate::cleanup()

{

    PFNWGLRELEASEPBUFFERDCARBPROC wglReleasePbufferDCARB =

        (PFNWGLRELEASEPBUFFERDCARBPROC) wglGetProcAddress("wglReleasePbufferDCARB");

    PFNWGLDESTROYPBUFFERARBPROC wglDestroyPbufferARB =

        (PFNWGLDESTROYPBUFFERARBPROC) wglGetProcAddress("wglDestroyPbufferARB");

    if (!invalid && wglReleasePbufferDCARB && wglDestroyPbufferARB) {

        wglReleasePbufferDCARB(pbuf, dc);

        wglDestroyPbufferARB(pbuf);

    }

    return true;

}

bool QGLPixelBuffer::bindToDynamicTexture(GLuint texture_id)

{

    Q_D(QGLPixelBuffer);

    if (d->invalid || !d->has_render_texture)

        return false;

    PFNWGLBINDTEXIMAGEARBPROC wglBindTexImageARB =

        (PFNWGLBINDTEXIMAGEARBPROC) wglGetProcAddress("wglBindTexImageARB");

    if (wglBindTexImageARB) {

        glBindTexture(GL_TEXTURE_2D, texture_id);

        return wglBindTexImageARB(d->pbuf, WGL_FRONT_LEFT_ARB);

    }

    return false;

}

void QGLPixelBuffer::releaseFromDynamicTexture()

{

    Q_D(QGLPixelBuffer);

    if (d->invalid || !d->has_render_texture)

        return;

    PFNWGLRELEASETEXIMAGEARBPROC wglReleaseTexImageARB =

        (PFNWGLRELEASETEXIMAGEARBPROC) wglGetProcAddress("wglReleaseTexImageARB");

    if (wglReleaseTexImageARB)

        wglReleaseTexImageARB(d->pbuf, WGL_FRONT_LEFT_ARB);

}

bool QGLPixelBuffer::hasOpenGLPbuffers()

{

    bool ret = false;

    QGLWidget *dmy = 0;

    if (!QGLContext::currentContext()) {

        dmy = new QGLWidget;

        dmy->makeCurrent();

    }

    PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB =

        (PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");

    if (wglGetExtensionsStringARB) {

        QString extensions(QLatin1String(wglGetExtensionsStringARB(wglGetCurrentDC())));

        if (extensions.contains(QLatin1String("WGL_ARB_pbuffer"))

            && extensions.contains(QLatin1String("WGL_ARB_pixel_format"))) {

            ret = true;

        }

    }

    if (dmy)

        delete dmy;

    return ret;

}

QT_END_NAMESPACE