/*
 * Copyright 2008 George Sapountzis
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifdef GLX_DIRECT_RENDERING

#include <X11/Xlib.h>
#include "glheader.h"
#include "glxclient.h"
#include "glcontextmodes.h"
#include <dlfcn.h>
#include "dri_common.h"

typedef struct __GLXDRIdisplayPrivateRec __GLXDRIdisplayPrivate;
typedef struct __GLXDRIcontextPrivateRec __GLXDRIcontextPrivate;
typedef struct __GLXDRIdrawablePrivateRec __GLXDRIdrawablePrivate;

struct __GLXDRIdisplayPrivateRec {
    __GLXDRIdisplay base;
};

struct __GLXDRIcontextPrivateRec {
    __GLXDRIcontext base;
    __DRIcontext *driContext;
    __GLXscreenConfigs *psc;
};

struct __GLXDRIdrawablePrivateRec {
    __GLXDRIdrawable base;

    GC gc;
    GC swapgc;

    XVisualInfo *visinfo;
    XImage *ximage;
    int bpp;
};

/**
 * swrast loader functions
 */

static Bool XCreateDrawable(__GLXDRIdrawablePrivate *pdp,
			    Display *dpy, XID drawable, int visualid)
{
    XGCValues gcvalues;
    long visMask;
    XVisualInfo visTemp;
    int num_visuals;

    /* create GC's */
    pdp->gc = XCreateGC(dpy, drawable, 0, NULL);
    pdp->swapgc = XCreateGC(dpy, drawable, 0, NULL);

    gcvalues.function = GXcopy;
    gcvalues.graphics_exposures = False;
    XChangeGC(dpy, pdp->gc, GCFunction, &gcvalues);
    XChangeGC(dpy, pdp->swapgc, GCFunction, &gcvalues);
    XChangeGC(dpy, pdp->swapgc, GCGraphicsExposures, &gcvalues);

    /* create XImage  */
    visTemp.screen = DefaultScreen(dpy);
    visTemp.visualid = visualid;
    visMask = (VisualScreenMask | VisualIDMask);
    pdp->visinfo = XGetVisualInfo(dpy, visMask, &visTemp, &num_visuals);

    pdp->ximage = XCreateImage(dpy,
			       pdp->visinfo->visual,
			       pdp->visinfo->depth,
			       ZPixmap, 0,   /* format, offset */
			       NULL,         /* data */
			       0, 0,         /* size */
			       32,           /* bitmap_pad */
			       0);           /* bytes_per_line */

    /* get the true number of bits per pixel */
    pdp->bpp = pdp->ximage->bits_per_pixel;

    return True;
}

static void XDestroyDrawable(__GLXDRIdrawablePrivate *pdp,
			     Display *dpy, XID drawable)
{
    XDestroyImage(pdp->ximage);
    XFree(pdp->visinfo);

    XFreeGC(dpy, pdp->gc);
    XFreeGC(dpy, pdp->swapgc);
}

static void
swrastGetDrawableInfo(__DRIdrawable *draw,
		      int *x, int *y, int *w, int *h,
		      void *loaderPrivate)
{
    __GLXDRIdrawablePrivate *pdp = loaderPrivate;
    __GLXDRIdrawable *pdraw = &(pdp->base);;
    Display *dpy = pdraw->psc->dpy;
    Drawable drawable;

    Window root;
    Status stat;
    unsigned int bw, depth;

    drawable = pdraw->xDrawable;

    stat = XGetGeometry(dpy, drawable, &root,
			x, y, (unsigned int *)w, (unsigned int *)h,
			&bw, &depth);
}

static inline int
bytes_per_line(int w, int bpp, unsigned mul)
{
    unsigned mask = mul - 1;

    return ((w * bpp + mask) & ~mask) / 8;
}

static void
swrastPutImage(__DRIdrawable *draw, int op,
	       int x, int y, int w, int h, char *data,
	       void *loaderPrivate)
{
    __GLXDRIdrawablePrivate *pdp = loaderPrivate;
    __GLXDRIdrawable *pdraw = &(pdp->base);;
    Display *dpy = pdraw->psc->dpy;
    Drawable drawable;
    XImage *ximage;
    GC gc;

    switch (op) {
    case __DRI_SWRAST_IMAGE_OP_DRAW:
	gc = pdp->gc;
	break;
    case __DRI_SWRAST_IMAGE_OP_SWAP:
	gc = pdp->swapgc;
	break;
    default:
	return;
    }

    drawable = pdraw->xDrawable;

    ximage = pdp->ximage;
    ximage->data = data;
    ximage->width = w;
    ximage->height = h;
    ximage->bytes_per_line = bytes_per_line(w, pdp->bpp, 32);

    XPutImage(dpy, drawable, gc, ximage, 0, 0, x, y, w, h);

    ximage->data = NULL;
}

static void
swrastGetImage(__DRIdrawable *draw,
	       int x, int y, int w, int h, char *data,
	       void *loaderPrivate)
{
    __GLXDRIdrawablePrivate *pdp = loaderPrivate;
    __GLXDRIdrawable *pdraw = &(pdp->base);;
    Display *dpy = pdraw->psc->dpy;
    Drawable drawable;
    XImage *ximage;

    drawable = pdraw->xDrawable;

    ximage = pdp->ximage;
    ximage->data = data;
    ximage->width = w;
    ximage->height = h;
    ximage->bytes_per_line = bytes_per_line(w, pdp->bpp, 32);

    XGetSubImage(dpy, drawable, x, y, w, h, ~0L, ZPixmap, ximage, 0, 0);

    ximage->data = NULL;
}

static const __DRIswrastLoaderExtension swrastLoaderExtension = {
    { __DRI_SWRAST_LOADER, __DRI_SWRAST_LOADER_VERSION },
    swrastGetDrawableInfo,
    swrastPutImage,
    swrastGetImage
};

static const __DRIextension *loader_extensions[] = {
    &systemTimeExtension.base,
    &swrastLoaderExtension.base,
    NULL
};

/**
 * GLXDRI functions
 */

static void driDestroyContext(__GLXDRIcontext *context,
			      __GLXscreenConfigs *psc, Display *dpy)
{
    __GLXDRIcontextPrivate *pcp = (__GLXDRIcontextPrivate *) context;
    const __DRIcoreExtension *core = pcp->psc->core;

    (*core->destroyContext)(pcp->driContext);

    Xfree(pcp);
}

static Bool driBindContext(__GLXDRIcontext *context,
			   __GLXDRIdrawable *draw, __GLXDRIdrawable *read)
{
    __GLXDRIcontextPrivate *pcp = (__GLXDRIcontextPrivate *) context;
    const __DRIcoreExtension *core = pcp->psc->core;

    return (*core->bindContext)(pcp->driContext,
				draw->driDrawable,
				read->driDrawable);
}

static void driUnbindContext(__GLXDRIcontext *context)
{
    __GLXDRIcontextPrivate *pcp = (__GLXDRIcontextPrivate *) context;
    const __DRIcoreExtension *core = pcp->psc->core;

    (*core->unbindContext)(pcp->driContext);
}

static __GLXDRIcontext *driCreateContext(__GLXscreenConfigs *psc,
					 const __GLcontextModes *mode,
					 GLXContext gc,
					 GLXContext shareList, int renderType)
{
    __GLXDRIcontextPrivate *pcp, *pcp_shared;
    __GLXDRIconfigPrivate *config = (__GLXDRIconfigPrivate *) mode;
    const __DRIcoreExtension *core = psc->core;
    __DRIcontext *shared = NULL;

    if (!psc || !psc->driScreen)
	return NULL;

    if (shareList) {
	pcp_shared = (__GLXDRIcontextPrivate *) shareList->driContext;
	shared = pcp_shared->driContext;
    }

    pcp = Xmalloc(sizeof *pcp);
    if (pcp == NULL)
	return NULL;

    pcp->psc = psc;
    pcp->driContext =
	(*core->createNewContext)(psc->__driScreen,
				  config->driConfig, shared, pcp);
    if (pcp->driContext == NULL) {
	Xfree(pcp);
	return NULL;
    }

    pcp->base.destroyContext = driDestroyContext;
    pcp->base.bindContext = driBindContext;
    pcp->base.unbindContext = driUnbindContext;

    return &pcp->base;
}

static void driDestroyDrawable(__GLXDRIdrawable *pdraw)
{
    __GLXDRIdrawablePrivate *pdp = (__GLXDRIdrawablePrivate *) pdraw;
    const __DRIcoreExtension *core = pdraw->psc->core;

    (*core->destroyDrawable)(pdraw->driDrawable);

    XDestroyDrawable(pdp, pdraw->psc->dpy, pdraw->drawable);
    Xfree(pdp);
}

static __GLXDRIdrawable *driCreateDrawable(__GLXscreenConfigs *psc,
					   XID xDrawable,
					   GLXDrawable drawable,
					   const __GLcontextModes *modes)
{
    __GLXDRIdrawable *pdraw;
    __GLXDRIdrawablePrivate *pdp;
    __GLXDRIconfigPrivate *config = (__GLXDRIconfigPrivate *) modes;
    const __DRIswrastExtension *swrast = psc->swrast;

    /* Old dri can't handle GLX 1.3+ drawable constructors. */
    if (xDrawable != drawable)
	return NULL;

    pdp = Xmalloc(sizeof(*pdp));
    if (!pdp)
	return NULL;

    pdraw = &(pdp->base);
    pdraw->xDrawable = xDrawable;
    pdraw->drawable = drawable;
    pdraw->psc = psc;

    XCreateDrawable(pdp, psc->dpy, xDrawable, modes->visualID);

    /* Create a new drawable */
    pdraw->driDrawable =
	(*swrast->createNewDrawable)(psc->__driScreen,
				     config->driConfig,
				     pdp);

    if (!pdraw->driDrawable) {
	XDestroyDrawable(pdp, psc->dpy, xDrawable);
	Xfree(pdp);
	return NULL;
    }

    pdraw->destroyDrawable = driDestroyDrawable;

    return pdraw;
}

static void driDestroyScreen(__GLXscreenConfigs *psc)
{
    /* Free the direct rendering per screen data */
    (*psc->core->destroyScreen)(psc->__driScreen);
    psc->__driScreen = NULL;
    if (psc->driver)
	dlclose(psc->driver);
}

static __GLXDRIscreen *driCreateScreen(__GLXscreenConfigs *psc, int screen,
				       __GLXdisplayPrivate *priv)
{
    __GLXDRIscreen *psp;
    const __DRIconfig **driver_configs;
    const __DRIextension **extensions;
    const char *driverName = "swrast";
    int i;

    psp = Xmalloc(sizeof *psp);
    if (psp == NULL)
	return NULL;

    /* Initialize per screen dynamic client GLX extensions */
    psc->ext_list_first_time = GL_TRUE;

    psc->driver = driOpenDriver(driverName);
    if (psc->driver == NULL)
	goto handle_error;

    extensions = dlsym(psc->driver, __DRI_DRIVER_EXTENSIONS);
    if (extensions == NULL) {
	ErrorMessageF("driver exports no extensions (%s)\n", dlerror());
	goto handle_error;
    }

    for (i = 0; extensions[i]; i++) {
	if (strcmp(extensions[i]->name, __DRI_CORE) == 0)
	    psc->core = (__DRIcoreExtension *) extensions[i];
	if (strcmp(extensions[i]->name, __DRI_SWRAST) == 0)
	    psc->swrast = (__DRIswrastExtension *) extensions[i];
    }

    if (psc->core == NULL || psc->swrast == NULL) {
	ErrorMessageF("core dri extension not found\n");
	goto handle_error;
    }

    psc->__driScreen =
	psc->swrast->createNewScreen(screen,
				     loader_extensions, &driver_configs, psc);
    if (psc->__driScreen == NULL) {
	ErrorMessageF("failed to create dri screen\n");
	goto handle_error;
    }

    driBindExtensions(psc, 0);

    psc->configs = driConvertConfigs(psc->core, psc->configs, driver_configs);
    psc->visuals = driConvertConfigs(psc->core, psc->visuals, driver_configs);

    psp->destroyScreen = driDestroyScreen;
    psp->createContext = driCreateContext;
    psp->createDrawable = driCreateDrawable;

    return psp;

 handle_error:
    Xfree(psp);

    if (psc->driver)
	dlclose(psc->driver);

    ErrorMessageF("reverting to indirect rendering\n");

    return NULL;
}

/* Called from __glXFreeDisplayPrivate.
 */
static void driDestroyDisplay(__GLXDRIdisplay *dpy)
{
    Xfree(dpy);
}

/*
 * Allocate, initialize and return a __DRIdisplayPrivate object.
 * This is called from __glXInitialize() when we are given a new
 * display pointer.
 */
_X_HIDDEN __GLXDRIdisplay *driswCreateDisplay(Display *dpy)
{
    __GLXDRIdisplayPrivate *pdpyp;

    pdpyp = Xmalloc(sizeof *pdpyp);
    if (pdpyp == NULL)
	return NULL;

    pdpyp->base.destroyDisplay = driDestroyDisplay;
    pdpyp->base.createScreen = driCreateScreen;

    return &pdpyp->base;
}

#endif /* GLX_DIRECT_RENDERING */