/*
 * Copyright 2002-2005 Jason Edmeades
 * Copyright 2002-2005 Raphael Junqueira
 * Copyright 2004 Christian Costa
 * Copyright 2005 Oliver Stieber
 * Copyright 2007-2011, 2013-2014 Stefan Dösinger for CodeWeavers
 * Copyright 2009-2010 Henri Verbeet for CodeWeavers
 *
 * 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 "config.h"
#include "wine/port.h"

#include "wined3d_private.h"

WINE_DEFAULT_DEBUG_CHANNEL(d3d);

#define WINED3D_BUFFER_HASDESC      0x01    /* A vertex description has been found. */
#define WINED3D_BUFFER_USE_BO       0x02    /* Use a buffer object for this buffer. */
#define WINED3D_BUFFER_PIN_SYSMEM   0x04    /* Keep a system memory copy for this buffer. */
#define WINED3D_BUFFER_DISCARD      0x08    /* A DISCARD lock has occurred since the last preload. */
#define WINED3D_BUFFER_APPLESYNC    0x10    /* Using sync as in GL_APPLE_flush_buffer_range. */

#define VB_MAXDECLCHANGES     100     /* After that number of decl changes we stop converting */
#define VB_RESETDECLCHANGE    1000    /* Reset the decl changecount after that number of draws */
#define VB_MAXFULLCONVERSIONS 5       /* Number of full conversions before we stop converting */
#define VB_RESETFULLCONVS     20      /* Reset full conversion counts after that number of draws */

static void wined3d_buffer_evict_sysmem(struct wined3d_buffer *buffer)
{
    if (buffer->flags & WINED3D_BUFFER_PIN_SYSMEM)
    {
        TRACE("Not evicting system memory for buffer %p.\n", buffer);
        return;
    }

    TRACE("Evicting system memory for buffer %p.\n", buffer);
    wined3d_buffer_invalidate_location(buffer, WINED3D_LOCATION_SYSMEM);
    wined3d_resource_free_sysmem(&buffer->resource);
}

static void buffer_invalidate_bo_range(struct wined3d_buffer *buffer, unsigned int offset, unsigned int size)
{
    if (!offset && (!size || size == buffer->resource.size))
        goto invalidate_all;

    if (offset > buffer->resource.size || size > buffer->resource.size - offset)
    {
        WARN("Invalid range specified, invalidating entire buffer.\n");
        goto invalidate_all;
    }

    if (buffer->modified_areas >= buffer->maps_size)
    {
        struct wined3d_map_range *new;

        if (!(new = HeapReAlloc(GetProcessHeap(), 0, buffer->maps, 2 * buffer->maps_size * sizeof(*buffer->maps))))
        {
            ERR("Failed to allocate maps array, invalidating entire buffer.\n");
            goto invalidate_all;
        }

        buffer->maps = new;
        buffer->maps_size *= 2;
    }

    buffer->maps[buffer->modified_areas].offset = offset;
    buffer->maps[buffer->modified_areas].size = size;
    ++buffer->modified_areas;
    return;

invalidate_all:
    buffer->modified_areas = 1;
    buffer->maps[0].offset = 0;
    buffer->maps[0].size = buffer->resource.size;
}

static inline void buffer_clear_dirty_areas(struct wined3d_buffer *This)
{
    This->modified_areas = 0;
}

static BOOL buffer_is_dirty(const struct wined3d_buffer *buffer)
{
    return !!buffer->modified_areas;
}

static BOOL buffer_is_fully_dirty(const struct wined3d_buffer *buffer)
{
    return buffer->modified_areas == 1
            && !buffer->maps->offset && buffer->maps->size == buffer->resource.size;
}

static void wined3d_buffer_validate_location(struct wined3d_buffer *buffer, DWORD location)
{
    TRACE("buffer %p, location %s.\n", buffer, wined3d_debug_location(location));

    if (location & WINED3D_LOCATION_BUFFER)
        buffer_clear_dirty_areas(buffer);

    buffer->locations |= location;

    TRACE("New locations flags are %s.\n", wined3d_debug_location(buffer->locations));
}

static void wined3d_buffer_invalidate_range(struct wined3d_buffer *buffer, DWORD location,
        unsigned int offset, unsigned int size)
{
    TRACE("buffer %p, location %s, offset %u, size %u.\n",
            buffer, wined3d_debug_location(location), offset, size);

    if (location & WINED3D_LOCATION_BUFFER)
        buffer_invalidate_bo_range(buffer, offset, size);

    buffer->locations &= ~location;

    TRACE("New locations flags are %s.\n", wined3d_debug_location(buffer->locations));

    if (!buffer->locations)
        ERR("Buffer %p does not have any up to date location.\n", buffer);
}

void wined3d_buffer_invalidate_location(struct wined3d_buffer *buffer, DWORD location)
{
    wined3d_buffer_invalidate_range(buffer, location, 0, 0);
}

/* Context activation is done by the caller. */
static void buffer_bind(struct wined3d_buffer *buffer, struct wined3d_context *context)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;

    if (buffer->buffer_type_hint == GL_ELEMENT_ARRAY_BUFFER)
        context_invalidate_state(context, STATE_INDEXBUFFER);

    GL_EXTCALL(glBindBuffer(buffer->buffer_type_hint, buffer->buffer_object));
}

/* Context activation is done by the caller. */
static void buffer_destroy_buffer_object(struct wined3d_buffer *buffer, const struct wined3d_context *context)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;
    struct wined3d_resource *resource = &buffer->resource;

    if (!buffer->buffer_object)
        return;

    GL_EXTCALL(glDeleteBuffers(1, &buffer->buffer_object));
    checkGLcall("glDeleteBuffers");
    buffer->buffer_object = 0;

    /* The stream source state handler might have read the memory of the
     * vertex buffer already and got the memory in the vbo which is not
     * valid any longer. Dirtify the stream source to force a reload. This
     * happens only once per changed vertexbuffer and should occur rather
     * rarely. */
    if (resource->bind_count)
    {
        if (buffer->bind_flags & WINED3D_BIND_VERTEX_BUFFER)
            device_invalidate_state(resource->device, STATE_STREAMSRC);
        if (buffer->bind_flags & WINED3D_BIND_INDEX_BUFFER)
            device_invalidate_state(resource->device, STATE_INDEXBUFFER);
        if (buffer->bind_flags & WINED3D_BIND_CONSTANT_BUFFER)
        {
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_VERTEX));
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_HULL));
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_DOMAIN));
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_GEOMETRY));
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_PIXEL));
            device_invalidate_state(resource->device, STATE_CONSTANT_BUFFER(WINED3D_SHADER_TYPE_COMPUTE));
        }
    }

    if (buffer->query)
    {
        wined3d_event_query_destroy(buffer->query);
        buffer->query = NULL;
    }
    buffer->flags &= ~WINED3D_BUFFER_APPLESYNC;
}

/* Context activation is done by the caller. */
static BOOL buffer_create_buffer_object(struct wined3d_buffer *buffer, struct wined3d_context *context)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;
    GLenum gl_usage = GL_STATIC_DRAW;
    GLenum error;

    TRACE("Creating an OpenGL buffer object for wined3d_buffer %p with usage %s.\n",
            buffer, debug_d3dusage(buffer->resource.usage));

    /* Make sure that the gl error is cleared. Do not use checkGLcall
     * here because checkGLcall just prints a fixme and continues. However,
     * if an error during VBO creation occurs we can fall back to non-VBO operation
     * with full functionality(but performance loss).
     */
    while (gl_info->gl_ops.gl.p_glGetError() != GL_NO_ERROR);

    /* Basically the FVF parameter passed to CreateVertexBuffer is no good.
     * The vertex declaration from the device determines how the data in the
     * buffer is interpreted. This means that on each draw call the buffer has
     * to be verified to check if the rhw and color values are in the correct
     * format. */

    GL_EXTCALL(glGenBuffers(1, &buffer->buffer_object));
    error = gl_info->gl_ops.gl.p_glGetError();
    if (!buffer->buffer_object || error != GL_NO_ERROR)
    {
        ERR("Failed to create a BO with error %s (%#x).\n", debug_glerror(error), error);
        goto fail;
    }

    buffer_bind(buffer, context);
    error = gl_info->gl_ops.gl.p_glGetError();
    if (error != GL_NO_ERROR)
    {
        ERR("Failed to bind the BO with error %s (%#x).\n", debug_glerror(error), error);
        goto fail;
    }

    if (buffer->resource.usage & WINED3DUSAGE_DYNAMIC)
    {
        TRACE("Buffer has WINED3DUSAGE_DYNAMIC set.\n");
        gl_usage = GL_STREAM_DRAW_ARB;

        if (gl_info->supported[APPLE_FLUSH_BUFFER_RANGE])
        {
            GL_EXTCALL(glBufferParameteriAPPLE(buffer->buffer_type_hint, GL_BUFFER_FLUSHING_UNMAP_APPLE, GL_FALSE));
            GL_EXTCALL(glBufferParameteriAPPLE(buffer->buffer_type_hint, GL_BUFFER_SERIALIZED_MODIFY_APPLE, GL_FALSE));
            checkGLcall("glBufferParameteriAPPLE");
            buffer->flags |= WINED3D_BUFFER_APPLESYNC;
        }
        /* No setup is needed here for GL_ARB_map_buffer_range. */
    }

    GL_EXTCALL(glBufferData(buffer->buffer_type_hint, buffer->resource.size, NULL, gl_usage));
    error = gl_info->gl_ops.gl.p_glGetError();
    if (error != GL_NO_ERROR)
    {
        ERR("glBufferData failed with error %s (%#x).\n", debug_glerror(error), error);
        goto fail;
    }

    buffer->buffer_object_usage = gl_usage;
    buffer_invalidate_bo_range(buffer, 0, 0);

    return TRUE;

fail:
    /* Clean up all BO init, but continue because we can work without a BO :-) */
    ERR("Failed to create a buffer object. Continuing, but performance issues may occur.\n");
    buffer->flags &= ~WINED3D_BUFFER_USE_BO;
    buffer_destroy_buffer_object(buffer, context);
    buffer_clear_dirty_areas(buffer);
    return FALSE;
}

static BOOL buffer_process_converted_attribute(struct wined3d_buffer *buffer,
        const enum wined3d_buffer_conversion_type conversion_type,
        const struct wined3d_stream_info_element *attrib, DWORD *stride_this_run)
{
    const struct wined3d_format *format = attrib->format;
    BOOL ret = FALSE;
    unsigned int i;
    DWORD_PTR data;

    /* Check for some valid situations which cause us pain. One is if the buffer is used for
     * constant attributes(stride = 0), the other one is if the buffer is used on two streams
     * with different strides. In the 2nd case we might have to drop conversion entirely,
     * it is possible that the same bytes are once read as FLOAT2 and once as UBYTE4N.
     */
    if (!attrib->stride)
    {
        FIXME("%s used with stride 0, let's hope we get the vertex stride from somewhere else.\n",
                debug_d3dformat(format->id));
    }
    else if (attrib->stride != *stride_this_run && *stride_this_run)
    {
        FIXME("Got two concurrent strides, %d and %d.\n", attrib->stride, *stride_this_run);
    }
    else
    {
        *stride_this_run = attrib->stride;
        if (buffer->stride != *stride_this_run)
        {
            /* We rely that this happens only on the first converted attribute that is found,
             * if at all. See above check
             */
            TRACE("Reconverting because converted attributes occur, and the stride changed.\n");
            buffer->stride = *stride_this_run;
            HeapFree(GetProcessHeap(), HEAP_ZERO_MEMORY, buffer->conversion_map);
            buffer->conversion_map = wined3d_calloc(buffer->stride, sizeof(*buffer->conversion_map));
            ret = TRUE;
        }
    }

    data = ((DWORD_PTR)attrib->data.addr) % buffer->stride;
    for (i = 0; i < format->attribute_size; ++i)
    {
        DWORD_PTR idx = (data + i) % buffer->stride;
        if (buffer->conversion_map[idx] != conversion_type)
        {
            TRACE("Byte %lu in vertex changed:\n", idx);
            TRACE("    It was type %#x, is %#x now.\n", buffer->conversion_map[idx], conversion_type);
            ret = TRUE;
            buffer->conversion_map[idx] = conversion_type;
        }
    }

    return ret;
}

#define WINED3D_BUFFER_FIXUP_D3DCOLOR   0x01
#define WINED3D_BUFFER_FIXUP_XYZRHW     0x02

static BOOL buffer_check_attribute(struct wined3d_buffer *This, const struct wined3d_stream_info *si,
        const struct wined3d_state *state, UINT attrib_idx, DWORD fixup_flags, DWORD *stride_this_run)
{
    const struct wined3d_stream_info_element *attrib = &si->elements[attrib_idx];
    enum wined3d_format_id format;
    BOOL ret = FALSE;

    /* Ignore attributes that do not have our vbo. After that check we can be sure that the attribute is
     * there, on nonexistent attribs the vbo is 0.
     */
    if (!(si->use_map & (1u << attrib_idx))
            || state->streams[attrib->stream_idx].buffer != This)
        return FALSE;

    format = attrib->format->id;
    /* Look for newly appeared conversion */
    if (fixup_flags & WINED3D_BUFFER_FIXUP_D3DCOLOR && format == WINED3DFMT_B8G8R8A8_UNORM)
    {
        ret = buffer_process_converted_attribute(This, CONV_D3DCOLOR, attrib, stride_this_run);
    }
    else if (fixup_flags & WINED3D_BUFFER_FIXUP_XYZRHW && si->position_transformed)
    {
        if (format != WINED3DFMT_R32G32B32A32_FLOAT)
        {
            FIXME("Unexpected format %s for transformed position.\n", debug_d3dformat(format));
            return FALSE;
        }

        ret = buffer_process_converted_attribute(This, CONV_POSITIONT, attrib, stride_this_run);
    }
    else if (This->conversion_map)
    {
        ret = buffer_process_converted_attribute(This, CONV_NONE, attrib, stride_this_run);
    }

    return ret;
}

static BOOL buffer_find_decl(struct wined3d_buffer *This, const struct wined3d_stream_info *si,
        const struct wined3d_state *state, DWORD fixup_flags)
{
    UINT stride_this_run = 0;
    BOOL ret = FALSE;

    /* In d3d7 the vertex buffer declaration NEVER changes because it is stored in the d3d7 vertex buffer.
     * Once we have our declaration there is no need to look it up again. Index buffers also never need
     * conversion, so once the (empty) conversion structure is created don't bother checking again
     */
    if (This->flags & WINED3D_BUFFER_HASDESC)
    {
        if(This->resource.usage & WINED3DUSAGE_STATICDECL) return FALSE;
    }

    if (!fixup_flags)
    {
        TRACE("No fixup required.\n");
        if(This->conversion_map)
        {
            HeapFree(GetProcessHeap(), 0, This->conversion_map);
            This->conversion_map = NULL;
            This->stride = 0;
            return TRUE;
        }

        return FALSE;
    }

    TRACE("Finding vertex buffer conversion information\n");
    /* Certain declaration types need some fixups before we can pass them to
     * opengl. This means D3DCOLOR attributes with fixed function vertex
     * processing, FLOAT4 POSITIONT with fixed function, and FLOAT16 if
     * GL_ARB_half_float_vertex is not supported.
     *
     * Note for d3d8 and d3d9:
     * The vertex buffer FVF doesn't help with finding them, we have to use
     * the decoded vertex declaration and pick the things that concern the
     * current buffer. A problem with this is that this can change between
     * draws, so we have to validate the information and reprocess the buffer
     * if it changes, and avoid false positives for performance reasons.
     * WineD3D doesn't even know the vertex buffer any more, it is managed
     * by the client libraries and passed to SetStreamSource and ProcessVertices
     * as needed.
     *
     * We have to distinguish between vertex shaders and fixed function to
     * pick the way we access the strided vertex information.
     *
     * This code sets up a per-byte array with the size of the detected
     * stride of the arrays in the buffer. For each byte we have a field
     * that marks the conversion needed on this byte. For example, the
     * following declaration with fixed function vertex processing:
     *
     *      POSITIONT, FLOAT4
     *      NORMAL, FLOAT3
     *      DIFFUSE, FLOAT16_4
     *      SPECULAR, D3DCOLOR
     *
     * Will result in
     * {                 POSITIONT                    }{             NORMAL                }{    DIFFUSE          }{SPECULAR }
     * [P][P][P][P][P][P][P][P][P][P][P][P][P][P][P][P][0][0][0][0][0][0][0][0][0][0][0][0][F][F][F][F][F][F][F][F][C][C][C][C]
     *
     * Where in this example map P means 4 component position conversion, 0
     * means no conversion, F means FLOAT16_2 conversion and C means D3DCOLOR
     * conversion (red / blue swizzle).
     *
     * If we're doing conversion and the stride changes we have to reconvert
     * the whole buffer. Note that we do not mind if the semantic changes,
     * we only care for the conversion type. So if the NORMAL is replaced
     * with a TEXCOORD, nothing has to be done, or if the DIFFUSE is replaced
     * with a D3DCOLOR BLENDWEIGHT we can happily dismiss the change. Some
     * conversion types depend on the semantic as well, for example a FLOAT4
     * texcoord needs no conversion while a FLOAT4 positiont needs one
     */

    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_POSITION,
            fixup_flags, &stride_this_run) || ret;
    fixup_flags &= ~WINED3D_BUFFER_FIXUP_XYZRHW;

    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_BLENDWEIGHT,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_BLENDINDICES,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_NORMAL,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_DIFFUSE,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_SPECULAR,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD0,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD1,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD2,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD3,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD4,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD5,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD6,
            fixup_flags, &stride_this_run) || ret;
    ret = buffer_check_attribute(This, si, state, WINED3D_FFP_TEXCOORD7,
            fixup_flags, &stride_this_run) || ret;

    if (!stride_this_run && This->conversion_map)
    {
        /* Sanity test */
        if (!ret) ERR("no converted attributes found, old conversion map exists, and no declaration change?\n");
        HeapFree(GetProcessHeap(), 0, This->conversion_map);
        This->conversion_map = NULL;
        This->stride = 0;
    }

    if (ret) TRACE("Conversion information changed\n");

    return ret;
}

static inline unsigned int fixup_d3dcolor(DWORD *dst_color)
{
    DWORD src_color = *dst_color;

    /* Color conversion like in draw_primitive_immediate_mode(). Watch out for
     * endianness. If we want this to work on big-endian machines as well we
     * have to consider more things.
     *
     * 0xff000000: Alpha mask
     * 0x00ff0000: Blue mask
     * 0x0000ff00: Green mask
     * 0x000000ff: Red mask
     */
    *dst_color = 0;
    *dst_color |= (src_color & 0xff00ff00u);         /* Alpha Green */
    *dst_color |= (src_color & 0x00ff0000u) >> 16;   /* Red */
    *dst_color |= (src_color & 0x000000ffu) << 16;   /* Blue */

    return sizeof(*dst_color);
}

static inline unsigned int fixup_transformed_pos(struct wined3d_vec4 *p)
{
    /* rhw conversion like in position_float4(). */
    if (p->w != 1.0f && p->w != 0.0f)
    {
        float w = 1.0f / p->w;
        p->x *= w;
        p->y *= w;
        p->z *= w;
        p->w = w;
    }

    return sizeof(*p);
}

ULONG CDECL wined3d_buffer_incref(struct wined3d_buffer *buffer)
{
    ULONG refcount = InterlockedIncrement(&buffer->resource.ref);

    TRACE("%p increasing refcount to %u.\n", buffer, refcount);

    return refcount;
}

/* Context activation is done by the caller. */
static void wined3d_buffer_upload_ranges(struct wined3d_buffer *buffer, struct wined3d_context *context,
        const void *data, unsigned int data_offset, unsigned int range_count, const struct wined3d_map_range *ranges)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;
    const struct wined3d_map_range *range;

    buffer_bind(buffer, context);

    while (range_count--)
    {
        range = &ranges[range_count];
        GL_EXTCALL(glBufferSubData(buffer->buffer_type_hint,
                range->offset, range->size, (BYTE *)data + range->offset - data_offset));
    }
    checkGLcall("glBufferSubData");
}

static void buffer_conversion_upload(struct wined3d_buffer *buffer, struct wined3d_context *context)
{
    unsigned int i, j, range_idx, start, end, vertex_count;
    BYTE *data;

    if (!wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_SYSMEM))
    {
        ERR("Failed to load system memory.\n");
        return;
    }
    buffer->flags |= WINED3D_BUFFER_PIN_SYSMEM;

    /* Now for each vertex in the buffer that needs conversion. */
    vertex_count = buffer->resource.size / buffer->stride;

    if (!(data = HeapAlloc(GetProcessHeap(), 0, buffer->resource.size)))
    {
        ERR("Out of memory.\n");
        return;
    }

    for (range_idx = 0; range_idx < buffer->modified_areas; ++range_idx)
    {
        start = buffer->maps[range_idx].offset;
        end = start + buffer->maps[range_idx].size;

        memcpy(data + start, (BYTE *)buffer->resource.heap_memory + start, end - start);
        for (i = start / buffer->stride; i < min((end / buffer->stride) + 1, vertex_count); ++i)
        {
            for (j = 0; j < buffer->stride;)
            {
                switch (buffer->conversion_map[j])
                {
                    case CONV_NONE:
                        /* Done already */
                        j += sizeof(DWORD);
                        break;
                    case CONV_D3DCOLOR:
                        j += fixup_d3dcolor((DWORD *) (data + i * buffer->stride + j));
                        break;
                    case CONV_POSITIONT:
                        j += fixup_transformed_pos((struct wined3d_vec4 *) (data + i * buffer->stride + j));
                        break;
                    default:
                        FIXME("Unimplemented conversion %d in shifted conversion.\n", buffer->conversion_map[j]);
                        ++j;
                }
            }
        }
    }

    wined3d_buffer_upload_ranges(buffer, context, data, 0, buffer->modified_areas, buffer->maps);

    HeapFree(GetProcessHeap(), 0, data);
}

static BOOL wined3d_buffer_prepare_location(struct wined3d_buffer *buffer,
        struct wined3d_context *context, DWORD location)
{
    switch (location)
    {
        case WINED3D_LOCATION_SYSMEM:
            if (buffer->resource.heap_memory)
                return TRUE;

            if (!wined3d_resource_allocate_sysmem(&buffer->resource))
            {
                ERR("Failed to allocate system memory.\n");
                return FALSE;
            }
            return TRUE;

        case WINED3D_LOCATION_BUFFER:
            if (buffer->buffer_object)
                return TRUE;

            if (!(buffer->flags & WINED3D_BUFFER_USE_BO))
            {
                WARN("Trying to create BO for buffer %p with no WINED3D_BUFFER_USE_BO.\n", buffer);
                return FALSE;
            }
            return buffer_create_buffer_object(buffer, context);

        default:
            ERR("Invalid location %s.\n", wined3d_debug_location(location));
            return FALSE;
    }
}

BOOL wined3d_buffer_load_location(struct wined3d_buffer *buffer,
        struct wined3d_context *context, DWORD location)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;

    TRACE("buffer %p, context %p, location %s.\n",
            buffer, context, wined3d_debug_location(location));

    if (buffer->locations & location)
    {
        TRACE("Location (%#x) is already up to date.\n", location);
        return TRUE;
    }

    if (!buffer->locations)
    {
        ERR("Buffer %p does not have any up to date location.\n", buffer);
        wined3d_buffer_validate_location(buffer, WINED3D_LOCATION_DISCARDED);
        return wined3d_buffer_load_location(buffer, context, location);
    }

    TRACE("Current buffer location %s.\n", wined3d_debug_location(buffer->locations));

    if (!wined3d_buffer_prepare_location(buffer, context, location))
        return FALSE;

    if (buffer->locations & WINED3D_LOCATION_DISCARDED)
    {
        TRACE("Buffer previously discarded, nothing to do.\n");
        wined3d_buffer_validate_location(buffer, location);
        wined3d_buffer_invalidate_location(buffer, WINED3D_LOCATION_DISCARDED);
        return TRUE;
    }

    switch (location)
    {
        case WINED3D_LOCATION_SYSMEM:
            buffer_bind(buffer, context);
            GL_EXTCALL(glGetBufferSubData(buffer->buffer_type_hint, 0, buffer->resource.size,
                    buffer->resource.heap_memory));
            checkGLcall("buffer download");
            break;

        case WINED3D_LOCATION_BUFFER:
            if (!buffer->conversion_map)
                wined3d_buffer_upload_ranges(buffer, context, buffer->resource.heap_memory,
                        0, buffer->modified_areas, buffer->maps);
            else
                buffer_conversion_upload(buffer, context);
            break;

        default:
            ERR("Invalid location %s.\n", wined3d_debug_location(location));
            return FALSE;
    }

    wined3d_buffer_validate_location(buffer, location);
    if (buffer->resource.heap_memory && location == WINED3D_LOCATION_BUFFER
            && !(buffer->resource.usage & WINED3DUSAGE_DYNAMIC))
        wined3d_buffer_evict_sysmem(buffer);

    return TRUE;
}

/* Context activation is done by the caller. */
BYTE *wined3d_buffer_load_sysmem(struct wined3d_buffer *buffer, struct wined3d_context *context)
{
    if (wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_SYSMEM))
        buffer->flags |= WINED3D_BUFFER_PIN_SYSMEM;
    return buffer->resource.heap_memory;
}

DWORD wined3d_buffer_get_memory(struct wined3d_buffer *buffer,
        struct wined3d_bo_address *data, DWORD locations)
{
    TRACE("buffer %p, data %p, locations %s.\n",
            buffer, data, wined3d_debug_location(locations));

    if (locations & WINED3D_LOCATION_BUFFER)
    {
        data->buffer_object = buffer->buffer_object;
        data->addr = NULL;
        return WINED3D_LOCATION_BUFFER;
    }
    if (locations & WINED3D_LOCATION_SYSMEM)
    {
        data->buffer_object = 0;
        data->addr = buffer->resource.heap_memory;
        return WINED3D_LOCATION_SYSMEM;
    }

    ERR("Unexpected locations %s.\n", wined3d_debug_location(locations));
    data->buffer_object = 0;
    data->addr = NULL;
    return 0;
}

static void buffer_unload(struct wined3d_resource *resource)
{
    struct wined3d_buffer *buffer = buffer_from_resource(resource);

    TRACE("buffer %p.\n", buffer);

    if (buffer->buffer_object)
    {
        struct wined3d_context *context;

        context = context_acquire(resource->device, NULL);

        wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_SYSMEM);
        wined3d_buffer_invalidate_location(buffer, WINED3D_LOCATION_BUFFER);
        buffer_destroy_buffer_object(buffer, context);
        buffer_clear_dirty_areas(buffer);

        context_release(context);

        HeapFree(GetProcessHeap(), 0, buffer->conversion_map);
        buffer->conversion_map = NULL;
        buffer->stride = 0;
        buffer->conversion_stride = 0;
        buffer->flags &= ~WINED3D_BUFFER_HASDESC;
    }

    resource_unload(resource);
}

static void wined3d_buffer_drop_bo(struct wined3d_buffer *buffer)
{
    buffer->flags &= ~WINED3D_BUFFER_USE_BO;
    buffer_unload(&buffer->resource);
}

static void wined3d_buffer_destroy_object(void *object)
{
    struct wined3d_buffer *buffer = object;
    struct wined3d_context *context;

    if (buffer->buffer_object)
    {
        context = context_acquire(buffer->resource.device, NULL);
        buffer_destroy_buffer_object(buffer, context);
        context_release(context);

        HeapFree(GetProcessHeap(), 0, buffer->conversion_map);
    }

    HeapFree(GetProcessHeap(), 0, buffer->maps);
    HeapFree(GetProcessHeap(), 0, buffer);
}

ULONG CDECL wined3d_buffer_decref(struct wined3d_buffer *buffer)
{
    ULONG refcount = InterlockedDecrement(&buffer->resource.ref);

    TRACE("%p decreasing refcount to %u.\n", buffer, refcount);

    if (!refcount)
    {
        buffer->resource.parent_ops->wined3d_object_destroyed(buffer->resource.parent);
        resource_cleanup(&buffer->resource);
        wined3d_cs_emit_destroy_object(buffer->resource.device->cs, wined3d_buffer_destroy_object, buffer);
    }

    return refcount;
}

void * CDECL wined3d_buffer_get_parent(const struct wined3d_buffer *buffer)
{
    TRACE("buffer %p.\n", buffer);

    return buffer->resource.parent;
}

/* The caller provides a context and binds the buffer */
static void buffer_sync_apple(struct wined3d_buffer *This, DWORD flags, const struct wined3d_gl_info *gl_info)
{
    enum wined3d_event_query_result ret;

    /* No fencing needs to be done if the app promises not to overwrite
     * existing data. */
    if (flags & WINED3D_MAP_NOOVERWRITE)
        return;

    if (flags & WINED3D_MAP_DISCARD)
    {
        GL_EXTCALL(glBufferData(This->buffer_type_hint, This->resource.size, NULL, This->buffer_object_usage));
        checkGLcall("glBufferData");
        return;
    }

    if(!This->query)
    {
        TRACE("Creating event query for buffer %p\n", This);

        if (!wined3d_event_query_supported(gl_info))
        {
            FIXME("Event queries not supported, dropping async buffer locks.\n");
            goto drop_query;
        }

        This->query = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*This->query));
        if (!This->query)
        {
            ERR("Failed to allocate event query memory, dropping async buffer locks.\n");
            goto drop_query;
        }

        /* Since we don't know about old draws a glFinish is needed once */
        gl_info->gl_ops.gl.p_glFinish();
        return;
    }
    TRACE("Synchronizing buffer %p\n", This);
    ret = wined3d_event_query_finish(This->query, This->resource.device);
    switch(ret)
    {
        case WINED3D_EVENT_QUERY_NOT_STARTED:
        case WINED3D_EVENT_QUERY_OK:
            /* All done */
            return;

        case WINED3D_EVENT_QUERY_WRONG_THREAD:
            WARN("Cannot synchronize buffer lock due to a thread conflict\n");
            goto drop_query;

        default:
            ERR("wined3d_event_query_finish returned %u, dropping async buffer locks\n", ret);
            goto drop_query;
    }

drop_query:
    if(This->query)
    {
        wined3d_event_query_destroy(This->query);
        This->query = NULL;
    }

    gl_info->gl_ops.gl.p_glFinish();
    GL_EXTCALL(glBufferParameteriAPPLE(This->buffer_type_hint, GL_BUFFER_SERIALIZED_MODIFY_APPLE, GL_TRUE));
    checkGLcall("glBufferParameteriAPPLE(This->buffer_type_hint, GL_BUFFER_SERIALIZED_MODIFY_APPLE, GL_TRUE)");
    This->flags &= ~WINED3D_BUFFER_APPLESYNC;
}

static void buffer_mark_used(struct wined3d_buffer *buffer)
{
    buffer->flags &= ~WINED3D_BUFFER_DISCARD;
}

/* Context activation is done by the caller. */
void wined3d_buffer_load(struct wined3d_buffer *buffer, struct wined3d_context *context,
        const struct wined3d_state *state)
{
    const struct wined3d_gl_info *gl_info = context->gl_info;
    BOOL decl_changed = FALSE;

    TRACE("buffer %p.\n", buffer);

    if (buffer->resource.map_count)
    {
        WARN("Buffer is mapped, skipping preload.\n");
        return;
    }

    buffer_mark_used(buffer);

    /* TODO: Make converting independent from VBOs */
    if (!(buffer->flags & WINED3D_BUFFER_USE_BO))
    {
        /* Not doing any conversion */
        return;
    }

    if (!wined3d_buffer_prepare_location(buffer, context, WINED3D_LOCATION_BUFFER))
    {
        ERR("Failed to prepare buffer location.\n");
        return;
    }

    /* Reading the declaration makes only sense if we have valid state information
     * (i.e., if this function is called during draws). */
    if (state)
    {
        DWORD fixup_flags = 0;

        if (!use_vs(state))
        {
            if (!gl_info->supported[ARB_VERTEX_ARRAY_BGRA] && !context->d3d_info->ffp_generic_attributes)
                fixup_flags |= WINED3D_BUFFER_FIXUP_D3DCOLOR;
            if (!context->d3d_info->xyzrhw)
                fixup_flags |= WINED3D_BUFFER_FIXUP_XYZRHW;
        }

        decl_changed = buffer_find_decl(buffer, &context->stream_info, state, fixup_flags);
        buffer->flags |= WINED3D_BUFFER_HASDESC;
    }

    if (!decl_changed && !(buffer->flags & WINED3D_BUFFER_HASDESC && buffer_is_dirty(buffer)))
    {
        ++buffer->draw_count;
        if (buffer->draw_count > VB_RESETDECLCHANGE)
            buffer->decl_change_count = 0;
        if (buffer->draw_count > VB_RESETFULLCONVS)
            buffer->full_conversion_count = 0;
        return;
    }

    /* If applications change the declaration over and over, reconverting all the time is a huge
     * performance hit. So count the declaration changes and release the VBO if there are too many
     * of them (and thus stop converting)
     */
    if (decl_changed)
    {
        ++buffer->decl_change_count;
        buffer->draw_count = 0;

        if (buffer->decl_change_count > VB_MAXDECLCHANGES
                || (buffer->conversion_map && (buffer->resource.usage & WINED3DUSAGE_DYNAMIC)))
        {
            FIXME("Too many declaration changes or converting dynamic buffer, stopping converting.\n");
            wined3d_buffer_drop_bo(buffer);
            return;
        }

        /* The declaration changed, reload the whole buffer. */
        WARN("Reloading buffer because of a vertex declaration change.\n");
        buffer_invalidate_bo_range(buffer, 0, 0);
    }
    else
    {
        /* However, it is perfectly fine to change the declaration every now and then. We don't want a game that
         * changes it every minute drop the VBO after VB_MAX_DECL_CHANGES minutes. So count draws without
         * decl changes and reset the decl change count after a specific number of them
         */
        if (buffer->conversion_map && buffer_is_fully_dirty(buffer))
        {
            ++buffer->full_conversion_count;
            if (buffer->full_conversion_count > VB_MAXFULLCONVERSIONS)
            {
                FIXME("Too many full buffer conversions, stopping converting.\n");
                wined3d_buffer_drop_bo(buffer);
                return;
            }
        }
        else
        {
            ++buffer->draw_count;
            if (buffer->draw_count > VB_RESETDECLCHANGE)
                buffer->decl_change_count = 0;
            if (buffer->draw_count > VB_RESETFULLCONVS)
                buffer->full_conversion_count = 0;
        }
    }

    if (!wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_BUFFER))
        ERR("Failed to load buffer location.\n");
}

struct wined3d_resource * CDECL wined3d_buffer_get_resource(struct wined3d_buffer *buffer)
{
    TRACE("buffer %p.\n", buffer);

    return &buffer->resource;
}

static HRESULT wined3d_buffer_map(struct wined3d_buffer *buffer, UINT offset, UINT size, BYTE **data, DWORD flags)
{
    struct wined3d_device *device = buffer->resource.device;
    struct wined3d_context *context;
    LONG count;
    BYTE *base;

    TRACE("buffer %p, offset %u, size %u, data %p, flags %#x.\n", buffer, offset, size, data, flags);

    /* Filter redundant WINED3D_MAP_DISCARD maps. The 3DMark2001 multitexture
     * fill rate test seems to depend on this. When we map a buffer with
     * GL_MAP_INVALIDATE_BUFFER_BIT, the driver is free to discard the
     * previous contents of the buffer. The r600g driver only does this when
     * the buffer is currently in use, while the proprietary NVIDIA driver
     * appears to do this unconditionally. */
    if (buffer->flags & WINED3D_BUFFER_DISCARD)
        flags &= ~WINED3D_MAP_DISCARD;
    count = ++buffer->resource.map_count;

    if (buffer->buffer_object)
    {
        unsigned int dirty_offset = offset, dirty_size = size;

        /* DISCARD invalidates the entire buffer, regardless of the specified
         * offset and size. Some applications also depend on the entire buffer
         * being uploaded in that case. Two such applications are Port Royale
         * and Darkstar One. */
        if (flags & WINED3D_MAP_DISCARD)
        {
            dirty_offset = 0;
            dirty_size = 0;
        }

        if (!(flags & (WINED3D_MAP_NOOVERWRITE | WINED3D_MAP_DISCARD | WINED3D_MAP_READONLY))
                || ((flags & WINED3D_MAP_READONLY) && (buffer->locations & WINED3D_LOCATION_SYSMEM))
                || buffer->flags & WINED3D_BUFFER_PIN_SYSMEM)
        {
            if (!(buffer->locations & WINED3D_LOCATION_SYSMEM))
            {
                context = context_acquire(device, NULL);
                wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_SYSMEM);
                context_release(context);
            }

            if (!(flags & WINED3D_MAP_READONLY))
                wined3d_buffer_invalidate_range(buffer, WINED3D_LOCATION_BUFFER, dirty_offset, dirty_size);
        }
        else
        {
            const struct wined3d_gl_info *gl_info;

            context = context_acquire(device, NULL);
            gl_info = context->gl_info;

            if (!(flags & WINED3D_MAP_DISCARD))
                wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_BUFFER);

            if (!(flags & WINED3D_MAP_READONLY))
                buffer_invalidate_bo_range(buffer, dirty_offset, dirty_size);

            if ((flags & WINED3D_MAP_DISCARD) && buffer->resource.heap_memory)
                wined3d_buffer_evict_sysmem(buffer);

            if (count == 1)
            {
                buffer_bind(buffer, context);

                if (gl_info->supported[ARB_MAP_BUFFER_RANGE])
                {
                    GLbitfield mapflags = wined3d_resource_gl_map_flags(flags);
                    buffer->map_ptr = GL_EXTCALL(glMapBufferRange(buffer->buffer_type_hint,
                            0, buffer->resource.size, mapflags));
                    checkGLcall("glMapBufferRange");
                }
                else
                {
                    if (buffer->flags & WINED3D_BUFFER_APPLESYNC)
                        buffer_sync_apple(buffer, flags, gl_info);
                    buffer->map_ptr = GL_EXTCALL(glMapBuffer(buffer->buffer_type_hint,
                            GL_READ_WRITE));
                    checkGLcall("glMapBuffer");
                }

                if (((DWORD_PTR)buffer->map_ptr) & (RESOURCE_ALIGNMENT - 1))
                {
                    WARN("Pointer %p is not %u byte aligned.\n", buffer->map_ptr, RESOURCE_ALIGNMENT);

                    GL_EXTCALL(glUnmapBuffer(buffer->buffer_type_hint));
                    checkGLcall("glUnmapBuffer");
                    buffer->map_ptr = NULL;

                    if (buffer->resource.usage & WINED3DUSAGE_DYNAMIC)
                    {
                        /* The extra copy is more expensive than not using VBOs at
                         * all on the Nvidia Linux driver, which is the only driver
                         * that returns unaligned pointers.
                         */
                        TRACE("Dynamic buffer, dropping VBO.\n");
                        wined3d_buffer_drop_bo(buffer);
                    }
                    else
                    {
                        TRACE("Falling back to doublebuffered operation.\n");
                        wined3d_buffer_load_location(buffer, context, WINED3D_LOCATION_SYSMEM);
                        buffer->flags |= WINED3D_BUFFER_PIN_SYSMEM;
                    }
                    TRACE("New pointer is %p.\n", buffer->resource.heap_memory);
                    buffer->map_ptr = NULL;
                }
            }

            context_release(context);
        }

        if (flags & WINED3D_MAP_DISCARD)
            buffer->flags |= WINED3D_BUFFER_DISCARD;
    }

    base = buffer->map_ptr ? buffer->map_ptr : buffer->resource.heap_memory;
    *data = base + offset;

    TRACE("Returning memory at %p (base %p, offset %u).\n", *data, base, offset);
    /* TODO: check Flags compatibility with buffer->currentDesc.Usage (see MSDN) */

    return WINED3D_OK;
}

static void wined3d_buffer_unmap(struct wined3d_buffer *buffer)
{
    ULONG i;

    TRACE("buffer %p.\n", buffer);

    /* In the case that the number of Unmap calls > the
     * number of Map calls, d3d returns always D3D_OK.
     * This is also needed to prevent Map from returning garbage on
     * the next call (this will happen if the lock_count is < 0). */
    if (!buffer->resource.map_count)
    {
        WARN("Unmap called without a previous map call.\n");
        return;
    }

    if (--buffer->resource.map_count)
    {
        /* Delay loading the buffer until everything is unlocked */
        TRACE("Ignoring unmap.\n");
        return;
    }

    if (buffer->map_ptr)
    {
        struct wined3d_device *device = buffer->resource.device;
        const struct wined3d_gl_info *gl_info;
        struct wined3d_context *context;

        context = context_acquire(device, NULL);
        gl_info = context->gl_info;

        buffer_bind(buffer, context);

        if (gl_info->supported[ARB_MAP_BUFFER_RANGE])
        {
            for (i = 0; i < buffer->modified_areas; ++i)
            {
                GL_EXTCALL(glFlushMappedBufferRange(buffer->buffer_type_hint,
                        buffer->maps[i].offset, buffer->maps[i].size));
                checkGLcall("glFlushMappedBufferRange");
            }
        }
        else if (buffer->flags & WINED3D_BUFFER_APPLESYNC)
        {
            for (i = 0; i < buffer->modified_areas; ++i)
            {
                GL_EXTCALL(glFlushMappedBufferRangeAPPLE(buffer->buffer_type_hint,
                        buffer->maps[i].offset, buffer->maps[i].size));
                checkGLcall("glFlushMappedBufferRangeAPPLE");
            }
        }

        GL_EXTCALL(glUnmapBuffer(buffer->buffer_type_hint));
        if (wined3d_settings.strict_draw_ordering)
            gl_info->gl_ops.gl.p_glFlush(); /* Flush to ensure ordering across contexts. */
        context_release(context);

        buffer_clear_dirty_areas(buffer);
        buffer->map_ptr = NULL;
    }
}

HRESULT wined3d_buffer_copy(struct wined3d_buffer *dst_buffer, unsigned int dst_offset,
        struct wined3d_buffer *src_buffer, unsigned int src_offset, unsigned int size)
{
    const struct wined3d_gl_info *gl_info;
    struct wined3d_bo_address dst, src;
    struct wined3d_context *context;
    struct wined3d_device *device;
    BYTE *dst_ptr, *src_ptr;
    DWORD dst_location;
    HRESULT hr;

    buffer_mark_used(dst_buffer);
    buffer_mark_used(src_buffer);

    device = dst_buffer->resource.device;

    context = context_acquire(device, NULL);
    gl_info = context->gl_info;

    dst_location = wined3d_buffer_get_memory(dst_buffer, &dst, dst_buffer->locations);
    wined3d_buffer_get_memory(src_buffer, &src, src_buffer->locations);

    if (dst.buffer_object && src.buffer_object)
    {
        if (gl_info->supported[ARB_COPY_BUFFER])
        {
            GL_EXTCALL(glBindBuffer(GL_COPY_READ_BUFFER, src.buffer_object));
            GL_EXTCALL(glBindBuffer(GL_COPY_WRITE_BUFFER, dst.buffer_object));
            GL_EXTCALL(glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER,
                    src_offset, dst_offset, size));
            checkGLcall("direct buffer copy");
        }
        else
        {
            if (FAILED(hr = wined3d_buffer_map(dst_buffer, dst_offset, size, &dst_ptr, 0)))
            {
                WARN("Failed to map dst_buffer, hr %#x.\n", hr);
                context_release(context);
                return WINED3DERR_INVALIDCALL;
            }
            if (FAILED(hr = wined3d_buffer_map(src_buffer, src_offset, size, &src_ptr, WINED3D_MAP_READONLY)))
            {
                WARN("Failed to map src_buffer, hr %#x.\n", hr);
                wined3d_buffer_unmap(dst_buffer);
                context_release(context);
                return WINED3DERR_INVALIDCALL;
            }

            memcpy(dst_ptr, src_ptr, size);

            wined3d_buffer_unmap(src_buffer);
            wined3d_buffer_unmap(dst_buffer);
        }
    }
    else if (!dst.buffer_object && src.buffer_object)
    {
        buffer_bind(src_buffer, context);
        GL_EXTCALL(glGetBufferSubData(src_buffer->buffer_type_hint, src_offset, size, dst.addr + dst_offset));
        checkGLcall("buffer download");
    }
    else if (dst.buffer_object && !src.buffer_object)
    {
        buffer_bind(dst_buffer, context);
        GL_EXTCALL(glBufferSubData(dst_buffer->buffer_type_hint, dst_offset, size, src.addr + src_offset));
        checkGLcall("buffer upload");
    }
    else
    {
        memcpy(dst.addr + dst_offset, src.addr + src_offset, size);
    }

    wined3d_buffer_invalidate_range(dst_buffer, ~dst_location, dst_offset, size);

    context_release(context);
    return WINED3D_OK;
}

void wined3d_buffer_upload_data(struct wined3d_buffer *buffer, struct wined3d_context *context,
        const struct wined3d_box *box, const void *data)
{
    struct wined3d_map_range range;

    if (box)
    {
        range.offset = box->left;
        range.size = box->right - box->left;
    }
    else
    {
        range.offset = 0;
        range.size = buffer->resource.size;
    }

    wined3d_buffer_upload_ranges(buffer, context, data, range.offset, 1, &range);
}

static ULONG buffer_resource_incref(struct wined3d_resource *resource)
{
    return wined3d_buffer_incref(buffer_from_resource(resource));
}

static ULONG buffer_resource_decref(struct wined3d_resource *resource)
{
    return wined3d_buffer_decref(buffer_from_resource(resource));
}

static void buffer_resource_preload(struct wined3d_resource *resource)
{
    struct wined3d_context *context;

    context = context_acquire(resource->device, NULL);
    wined3d_buffer_load(buffer_from_resource(resource), context, NULL);
    context_release(context);
}

static HRESULT buffer_resource_sub_resource_map(struct wined3d_resource *resource, unsigned int sub_resource_idx,
        struct wined3d_map_desc *map_desc, const struct wined3d_box *box, DWORD flags)
{
    struct wined3d_buffer *buffer = buffer_from_resource(resource);
    UINT offset, size;

    if (sub_resource_idx)
    {
        WARN("Invalid sub_resource_idx %u.\n", sub_resource_idx);
        return E_INVALIDARG;
    }

    if (box)
    {
        offset = box->left;
        size = box->right - box->left;
    }
    else
    {
        offset = size = 0;
    }

    map_desc->row_pitch = map_desc->slice_pitch = buffer->desc.byte_width;
    return wined3d_buffer_map(buffer, offset, size, (BYTE **)&map_desc->data, flags);
}

static HRESULT buffer_resource_sub_resource_unmap(struct wined3d_resource *resource, unsigned int sub_resource_idx)
{
    if (sub_resource_idx)
    {
        WARN("Invalid sub_resource_idx %u.\n", sub_resource_idx);
        return E_INVALIDARG;
    }

    wined3d_buffer_unmap(buffer_from_resource(resource));
    return WINED3D_OK;
}

static const struct wined3d_resource_ops buffer_resource_ops =
{
    buffer_resource_incref,
    buffer_resource_decref,
    buffer_resource_preload,
    buffer_unload,
    buffer_resource_sub_resource_map,
    buffer_resource_sub_resource_unmap,
};

static GLenum buffer_type_hint_from_bind_flags(const struct wined3d_gl_info *gl_info,
        unsigned int bind_flags)
{
    if (bind_flags == WINED3D_BIND_INDEX_BUFFER)
        return GL_ELEMENT_ARRAY_BUFFER;

    if (bind_flags & (WINED3D_BIND_SHADER_RESOURCE | WINED3D_BIND_UNORDERED_ACCESS)
            && gl_info->supported[ARB_TEXTURE_BUFFER_OBJECT])
        return GL_TEXTURE_BUFFER;

    if (bind_flags & WINED3D_BIND_CONSTANT_BUFFER)
        return GL_UNIFORM_BUFFER;

    if (bind_flags & ~(WINED3D_BIND_VERTEX_BUFFER | WINED3D_BIND_INDEX_BUFFER))
        FIXME("Unhandled bind flags %#x.\n", bind_flags);

    return GL_ARRAY_BUFFER;
}

static HRESULT buffer_init(struct wined3d_buffer *buffer, struct wined3d_device *device,
        UINT size, DWORD usage, enum wined3d_format_id format_id, enum wined3d_pool pool, unsigned int bind_flags,
        const struct wined3d_sub_resource_data *data, void *parent, const struct wined3d_parent_ops *parent_ops)
{
    const struct wined3d_gl_info *gl_info = &device->adapter->gl_info;
    const struct wined3d_format *format = wined3d_get_format(gl_info, format_id, usage);
    BOOL dynamic_buffer_ok;
    HRESULT hr;

    if (!size)
    {
        WARN("Size 0 requested, returning WINED3DERR_INVALIDCALL.\n");
        return WINED3DERR_INVALIDCALL;
    }

    if (data && !data->data)
    {
        WARN("Invalid sub-resource data specified.\n");
        return E_INVALIDARG;
    }

    hr = resource_init(&buffer->resource, device, WINED3D_RTYPE_BUFFER, format,
            WINED3D_MULTISAMPLE_NONE, 0, usage, pool, size, 1, 1, size, parent, parent_ops, &buffer_resource_ops);
    if (FAILED(hr))
    {
        WARN("Failed to initialize resource, hr %#x.\n", hr);
        return hr;
    }
    buffer->buffer_type_hint = buffer_type_hint_from_bind_flags(gl_info, bind_flags);
    buffer->bind_flags = bind_flags;
    buffer->locations = WINED3D_LOCATION_SYSMEM;

    TRACE("buffer %p, size %#x, usage %#x, format %s, memory @ %p.\n",
            buffer, buffer->resource.size, buffer->resource.usage,
            debug_d3dformat(buffer->resource.format->id), buffer->resource.heap_memory);

    if (device->create_parms.flags & WINED3DCREATE_SOFTWARE_VERTEXPROCESSING || pool == WINED3D_POOL_MANAGED)
    {
        /* SWvp and managed buffers always return the same pointer in buffer
         * maps and retain data in DISCARD maps. Keep a system memory copy of
         * the buffer to provide the same behavior to the application. */
        TRACE("Using doublebuffer mode.\n");
        buffer->flags |= WINED3D_BUFFER_PIN_SYSMEM;
    }

    /* Observations show that draw_primitive_immediate_mode() is faster on
     * dynamic vertex buffers than converting + draw_primitive_arrays().
     * (Half-Life 2 and others.) */
    dynamic_buffer_ok = gl_info->supported[APPLE_FLUSH_BUFFER_RANGE] || gl_info->supported[ARB_MAP_BUFFER_RANGE];

    if (!gl_info->supported[ARB_VERTEX_BUFFER_OBJECT])
    {
        TRACE("Not creating a BO because GL_ARB_vertex_buffer is not supported.\n");
    }
    else if (buffer->resource.pool == WINED3D_POOL_SYSTEM_MEM)
    {
        TRACE("Not creating a BO because the buffer is in system memory.\n");
    }
    else if (!dynamic_buffer_ok && (buffer->resource.usage & WINED3DUSAGE_DYNAMIC))
    {
        TRACE("Not creating a BO because the buffer has dynamic usage and no GL support.\n");
    }
    else
    {
        buffer->flags |= WINED3D_BUFFER_USE_BO;
    }

    if (!(buffer->maps = HeapAlloc(GetProcessHeap(), 0, sizeof(*buffer->maps))))
    {
        ERR("Out of memory.\n");
        buffer_unload(&buffer->resource);
        resource_cleanup(&buffer->resource);
        wined3d_resource_wait_idle(&buffer->resource);
        return E_OUTOFMEMORY;
    }
    buffer->maps_size = 1;

    if (data)
        wined3d_device_update_sub_resource(device, &buffer->resource,
                0, NULL, data->data, data->row_pitch, data->slice_pitch);

    return WINED3D_OK;
}

HRESULT CDECL wined3d_buffer_create(struct wined3d_device *device, const struct wined3d_buffer_desc *desc,
        const struct wined3d_sub_resource_data *data, void *parent, const struct wined3d_parent_ops *parent_ops,
        struct wined3d_buffer **buffer)
{
    struct wined3d_buffer *object;
    HRESULT hr;

    TRACE("device %p, desc %p, data %p, parent %p, parent_ops %p, buffer %p.\n",
            device, desc, data, parent, parent_ops, buffer);

    object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*object));
    if (!object)
        return E_OUTOFMEMORY;

    FIXME("Ignoring access flags (pool).\n");

    hr = buffer_init(object, device, desc->byte_width, desc->usage, WINED3DFMT_UNKNOWN,
            WINED3D_POOL_MANAGED, desc->bind_flags, data, parent, parent_ops);
    if (FAILED(hr))
    {
        WARN("Failed to initialize buffer, hr %#x.\n", hr);
        HeapFree(GetProcessHeap(), 0, object);
        return hr;
    }
    object->desc = *desc;

    TRACE("Created buffer %p.\n", object);

    *buffer = object;

    return WINED3D_OK;
}

HRESULT CDECL wined3d_buffer_create_vb(struct wined3d_device *device, UINT size, DWORD usage, enum wined3d_pool pool,
        void *parent, const struct wined3d_parent_ops *parent_ops, struct wined3d_buffer **buffer)
{
    struct wined3d_buffer *object;
    HRESULT hr;

    TRACE("device %p, size %u, usage %#x, pool %#x, parent %p, parent_ops %p, buffer %p.\n",
            device, size, usage, pool, parent, parent_ops, buffer);

    if (pool == WINED3D_POOL_SCRATCH)
    {
        /* The d3d9 tests shows that this is not allowed. It doesn't make much
         * sense anyway, SCRATCH buffers wouldn't be usable anywhere. */
        WARN("Vertex buffer in WINED3D_POOL_SCRATCH requested, returning WINED3DERR_INVALIDCALL.\n");
        *buffer = NULL;
        return WINED3DERR_INVALIDCALL;
    }

    object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*object));
    if (!object)
    {
        *buffer = NULL;
        return WINED3DERR_OUTOFVIDEOMEMORY;
    }

    hr = buffer_init(object, device, size, usage, WINED3DFMT_UNKNOWN,
            pool, WINED3D_BIND_VERTEX_BUFFER, NULL, parent, parent_ops);
    if (FAILED(hr))
    {
        WARN("Failed to initialize buffer, hr %#x.\n", hr);
        HeapFree(GetProcessHeap(), 0, object);
        return hr;
    }

    TRACE("Created buffer %p.\n", object);
    *buffer = object;

    return WINED3D_OK;
}

HRESULT CDECL wined3d_buffer_create_ib(struct wined3d_device *device, UINT size, DWORD usage, enum wined3d_pool pool,
        void *parent, const struct wined3d_parent_ops *parent_ops, struct wined3d_buffer **buffer)
{
    struct wined3d_buffer *object;
    HRESULT hr;

    TRACE("device %p, size %u, usage %#x, pool %#x, parent %p, parent_ops %p, buffer %p.\n",
            device, size, usage, pool, parent, parent_ops, buffer);

    object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*object));
    if (!object)
    {
        *buffer = NULL;
        return WINED3DERR_OUTOFVIDEOMEMORY;
    }

    hr = buffer_init(object, device, size, usage | WINED3DUSAGE_STATICDECL,
            WINED3DFMT_UNKNOWN, pool, WINED3D_BIND_INDEX_BUFFER, NULL,
            parent, parent_ops);
    if (FAILED(hr))
    {
        WARN("Failed to initialize buffer, hr %#x\n", hr);
        HeapFree(GetProcessHeap(), 0, object);
        return hr;
    }

    TRACE("Created buffer %p.\n", object);
    *buffer = object;

    return WINED3D_OK;
}