/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
   Copyright (C) 2009 Red Hat, Inc.

   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, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "gl_canvas.h"
#include "quic.h"
#include "rop3.h"
#include "region.h"
#include "glc.h"

#define GL_CANVAS
#include "canvas_base.c"

typedef struct GLCanvas GLCanvas;

struct GLCanvas {
    CanvasBase base;
    GLCCtx glc;
    void *private_data;
    int private_data_size;
    int textures_lost;
};

static inline uint8_t *copy_opposite_image(GLCanvas *canvas, void *data, int stride, int height)
{
    uint8_t *ret_data = (uint8_t *)data;
    uint8_t *dest;
    uint8_t *src;
    int i;

    if (!canvas->private_data) {
        canvas->private_data = spice_malloc_n(height, stride);
        if (!canvas->private_data) {
            return ret_data;
        }
        canvas->private_data_size = stride * height;
    }

    if (canvas->private_data_size < (stride * height)) {
        free(canvas->private_data);
        canvas->private_data = spice_malloc_n(height, stride);
        if (!canvas->private_data) {
            return ret_data;
        }
        canvas->private_data_size = stride * height;
    }

    dest = (uint8_t *)canvas->private_data;
    src = (uint8_t *)data + (height - 1) * stride;

    for (i = 0; i < height; ++i) {
        memcpy(dest, src, stride);
        dest += stride;
        src -= stride;
    }
    return (uint8_t *)canvas->private_data;
}

static pixman_image_t *canvas_surf_to_trans_surf(GLCImage *image,
                                                 uint32_t trans_color)
{
    int width = image->width;
    int height = image->height;
    uint8_t *src_line;
    uint8_t *end_src_line;
    int src_stride;
    uint8_t *dest_line;
    int dest_stride;
    pixman_image_t *ret;
    int i;

    ret = pixman_image_create_bits(PIXMAN_a8r8g8b8, width, height, NULL, 0);
    if (ret == NULL) {
        spice_critical("create surface failed");
        return NULL;
    }

    src_line = image->pixels;
    src_stride = image->stride;
    end_src_line = src_line + src_stride * height;

    dest_line = (uint8_t *)pixman_image_get_data(ret);
    dest_stride = pixman_image_get_stride(ret);

    for (; src_line < end_src_line; src_line += src_stride, dest_line += dest_stride) {
        for (i = 0; i < width; i++) {
            if ((((uint32_t*)src_line)[i] & 0x00ffffff) == trans_color) {
                ((uint32_t*)dest_line)[i] = 0;
            } else {
                ((uint32_t*)dest_line)[i] = (((uint32_t*)src_line)[i]) | 0xff000000;
            }
        }
    }

    return ret;
}

static GLCPath get_path(GLCanvas *canvas, SpicePath *s)
{
    GLCPath path = glc_path_create(canvas->glc);
    int i;

    for (i = 0; i < s->num_segments; i++) {
        SpicePathSeg* seg = s->segments[i];
        SpicePointFix* point = seg->points;
        SpicePointFix* end_point = point + seg->count;

        if (seg->flags & SPICE_PATH_BEGIN) {
            glc_path_move_to(path, fix_to_double(point->x), fix_to_double(point->y));
            point++;
        }

        if (seg->flags & SPICE_PATH_BEZIER) {
            spice_return_val_if_fail((point - end_point) % 3 == 0, path);
            for (; point + 2 < end_point; point += 3) {
                glc_path_curve_to(path,
                                  fix_to_double(point[0].x), fix_to_double(point[0].y),
                                  fix_to_double(point[1].x), fix_to_double(point[1].y),
                                  fix_to_double(point[2].x), fix_to_double(point[2].y));
            }
        } else {
            for (; point < end_point; point++) {
                glc_path_line_to(path, fix_to_double(point->x), fix_to_double(point->y));
            }
        }
        if (seg->flags & SPICE_PATH_END) {
            if (seg->flags & SPICE_PATH_CLOSE) {
                glc_path_close(path);
            }
        }
    }

    return path;
}

#define SET_GLC_RECT(dest, src) {                   \
    (dest)->x = (src)->left;                        \
    (dest)->y = (src)->top;                         \
    (dest)->width = (src)->right - (src)->left;     \
    (dest)->height = (src)->bottom - (src)->top;    \
}

#define SET_GLC_BOX(dest, src) {                    \
    (dest)->x = (src)->x1;                          \
    (dest)->y = (src)->y1;                          \
    (dest)->width = (src)->x2 - (src)->x1;          \
    (dest)->height = (src)->y2 - (src)->y1;         \
}

static void set_clip(GLCanvas *canvas, SpiceRect *bbox, SpiceClip *clip)
{
    GLCRect rect;
    glc_clip_reset(canvas->glc);

    switch (clip->type) {
    case SPICE_CLIP_TYPE_NONE:
        break;
    case SPICE_CLIP_TYPE_RECTS: {
        uint32_t n = clip->rects->num_rects;
        SpiceRect *now = clip->rects->rects;
        SpiceRect *end = now + n;

        if (n == 0) {
            rect.x = rect.y = 0;
            rect.width = rect.height = 0;
            glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_SET);
            break;
        } else {
            SET_GLC_RECT(&rect, now);
            glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_SET);
        }

        for (now++; now < end; now++) {
            SET_GLC_RECT(&rect, now);
            glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_OR);
        }
        break;
    }
    default:
        spice_warn_if_reached();
        return;
    }
}

static void set_mask(GLCanvas *canvas, SpiceQMask *mask, int x, int y)
{
    pixman_image_t *image;

    if (!mask->bitmap ||
        !(image = canvas_get_mask(&canvas->base, mask, NULL))) {
        glc_clear_mask(canvas->glc, GLC_MASK_A);
        return;
    }


    glc_set_mask(canvas->glc, x - mask->pos.x, y - mask->pos.y,
                 pixman_image_get_width(image),
                 pixman_image_get_height(image),
                 pixman_image_get_stride(image),
                 (uint8_t *)pixman_image_get_data(image), GLC_MASK_A);
}

static inline void surface_to_image(GLCanvas *canvas, pixman_image_t *surface, GLCImage *image,
                                    int ignore_stride)
{
    int depth = pixman_image_get_depth(surface);

    spice_return_if_fail(depth == 32 || depth == 24);
    image->format = (depth == 24) ? GLC_IMAGE_RGB32 : GLC_IMAGE_ARGB32;
    image->width = pixman_image_get_width(surface);
    image->height = pixman_image_get_height(surface);
    image->stride = pixman_image_get_stride(surface);
    image->pixels = (uint8_t *)pixman_image_get_data(surface);
    image->pallet = NULL;
    if (ignore_stride) {
        return;
    }
    if (image->stride < 0) {
        image->stride = -image->stride;
        image->pixels = image->pixels - (image->height - 1) * image->stride;
    } else {
        image->pixels = copy_opposite_image(canvas, image->pixels, image->stride, image->height);
    }
}

static void set_brush(GLCanvas *canvas, SpiceBrush *brush)
{
    switch (brush->type) {
    case SPICE_BRUSH_TYPE_SOLID: {
        uint32_t color = brush->u.color;
        double r, g, b;

        b = (double)(color & canvas->base.color_mask) / canvas->base.color_mask;
        color >>= canvas->base.color_shift;
        g = (double)(color & canvas->base.color_mask) / canvas->base.color_mask;
        color >>= canvas->base.color_shift;
        r = (double)(color & canvas->base.color_mask) / canvas->base.color_mask;
        glc_set_rgb(canvas->glc, r, g, b);
        break;
    }
    case SPICE_BRUSH_TYPE_PATTERN: {
        GLCImage image;
        GLCPattern pattern;
        pixman_image_t *surface;

        surface = canvas_get_image(&canvas->base, brush->u.pattern.pat, FALSE);
        surface_to_image(canvas, surface, &image, 0);

        pattern = glc_pattern_create(canvas->glc, -brush->u.pattern.pos.x,
                                     -brush->u.pattern.pos.y, &image);

        glc_set_pattern(canvas->glc, pattern);
        glc_pattern_destroy(pattern);
        pixman_image_unref (surface);
    }
    case SPICE_BRUSH_TYPE_NONE:
        return;
    default:
        spice_warn_if_reached();
        return;
    }
}

static void set_op(GLCanvas *canvas, uint16_t rop_decriptor)
{
    GLCOp op;

    switch (rop_decriptor) {
    case SPICE_ROPD_OP_PUT:
        op = GLC_OP_COPY;
        break;
    case SPICE_ROPD_OP_XOR:
        op = GLC_OP_XOR;
        break;
    case SPICE_ROPD_OP_BLACKNESS:
        op = GLC_OP_CLEAR;
        break;
    case SPICE_ROPD_OP_WHITENESS:
        op = GLC_OP_SET;
        break;
    case SPICE_ROPD_OP_PUT | SPICE_ROPD_INVERS_BRUSH:
    case SPICE_ROPD_OP_PUT | SPICE_ROPD_INVERS_SRC:
        op = GLC_OP_COPY_INVERTED;
        break;
    case SPICE_ROPD_OP_INVERS:
        op = GLC_OP_INVERT;
        break;
    case SPICE_ROPD_OP_AND:
        op = GLC_OP_AND;
        break;
    case SPICE_ROPD_OP_AND | SPICE_ROPD_INVERS_RES:
        op = GLC_OP_NAND;
        break;
    case SPICE_ROPD_OP_OR:
        op = GLC_OP_OR;
        break;
    case SPICE_ROPD_OP_OR | SPICE_ROPD_INVERS_RES:
        op = GLC_OP_NOR;
        break;
    case SPICE_ROPD_OP_XOR | SPICE_ROPD_INVERS_RES:
        op = GLC_OP_EQUIV;
        break;
    case SPICE_ROPD_OP_AND | SPICE_ROPD_INVERS_DEST:
        op = GLC_OP_AND_REVERSE;
        break;
    case SPICE_ROPD_OP_AND | SPICE_ROPD_INVERS_BRUSH:
    case SPICE_ROPD_OP_AND | SPICE_ROPD_INVERS_SRC:
        op = GLC_OP_AND_INVERTED;
        break;
    case SPICE_ROPD_OP_OR | SPICE_ROPD_INVERS_DEST:
        op = GLC_OP_OR_REVERSE;
        break;
    case SPICE_ROPD_OP_OR | SPICE_ROPD_INVERS_BRUSH:
    case SPICE_ROPD_OP_OR | SPICE_ROPD_INVERS_SRC:
        op = GLC_OP_OR_INVERTED;
        break;
    default:
        spice_warning("GLC_OP_NOOP");
        op = GLC_OP_NOOP;
    }
    glc_set_op(canvas->glc, op);
}

static void gl_canvas_draw_fill(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceFill *fill)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCRect rect;
    set_clip(canvas, bbox, clip);
    set_mask(canvas, &fill->mask, bbox->left, bbox->top);
    set_brush(canvas, &fill->brush);
    set_op(canvas, fill->rop_descriptor);
    SET_GLC_RECT(&rect, bbox);

    glc_fill_rect(canvas->glc, &rect);
    glc_flush(canvas->glc);
}

static void gl_canvas_draw_copy(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceCopy *copy)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *surface;
    GLCRecti src;
    GLCRecti dest;
    GLCImage image;

    set_clip(canvas, bbox, clip);
    set_mask(canvas, &copy->mask, bbox->left, bbox->top);
    set_op(canvas, copy->rop_descriptor);

    //todo: optimize get_image (use ogl conversion + remove unnecessary copy of 32bpp)
    surface = canvas_get_image(&canvas->base, copy->src_bitmap, FALSE);
    surface_to_image(canvas, surface, &image, 0);
    SET_GLC_RECT(&dest, bbox);
    SET_GLC_RECT(&src, &copy->src_area);
    image.format = GLC_IMAGE_RGB32;
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, 1);

    pixman_image_unref(surface);
    glc_flush(canvas->glc);
}

static void gl_canvas_draw_opaque(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceOpaque *opaque)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *surface;
    GLCRecti src;
    GLCRecti dest;
    GLCRect fill_rect;
    GLCImage image;

    set_clip(canvas, bbox, clip);
    set_mask(canvas, &opaque->mask, bbox->left, bbox->top);

    glc_set_op(canvas->glc, (opaque->rop_descriptor & SPICE_ROPD_INVERS_SRC) ? GLC_OP_COPY_INVERTED :
               GLC_OP_COPY);
    surface = canvas_get_image(&canvas->base, opaque->src_bitmap, FALSE);
    surface_to_image(canvas, surface, &image, 0);
    SET_GLC_RECT(&dest, bbox);
    SET_GLC_RECT(&src, &opaque->src_area);
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, 1);
    pixman_image_unref(surface);

    set_brush(canvas, &opaque->brush);
    set_op(canvas, opaque->rop_descriptor & ~SPICE_ROPD_INVERS_SRC);
    SET_GLC_RECT(&fill_rect, bbox);
    glc_fill_rect(canvas->glc, &fill_rect);

    glc_flush(canvas->glc);
}

static void gl_canvas_draw_alpha_blend(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceAlphaBlend *alpha_blend)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *surface;
    GLCRecti src;
    GLCRecti dest;
    GLCImage image;

    set_clip(canvas, bbox, clip);
    glc_clear_mask(canvas->glc, GLC_MASK_A);
    glc_set_op(canvas->glc, GLC_OP_COPY);

    surface = canvas_get_image(&canvas->base, alpha_blend->src_bitmap, FALSE);
    surface_to_image(canvas, surface, &image, 0);
    SET_GLC_RECT(&dest, bbox);
    SET_GLC_RECT(&src, &alpha_blend->src_area);
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, (double)alpha_blend->alpha / 0xff);

    pixman_image_unref(surface);
    glc_flush(canvas->glc);
}

static void gl_canvas_draw_blend(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceBlend *blend)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *surface;
    GLCRecti src;
    GLCRecti dest;
    GLCImage image;

    set_clip(canvas, bbox, clip);
    set_mask(canvas, &blend->mask, bbox->left, bbox->top);
    set_op(canvas, blend->rop_descriptor);

    surface = canvas_get_image(&canvas->base, blend->src_bitmap, FALSE);
    SET_GLC_RECT(&dest, bbox);
    SET_GLC_RECT(&src, &blend->src_area);
    surface_to_image(canvas, surface, &image, 0);
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, 1);

    pixman_image_unref(surface);
    glc_flush(canvas->glc);
}

static void gl_canvas_draw_transparent(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceTransparent *transparent)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *surface;
    pixman_image_t *trans_surf;
    GLCImage image;
    GLCRecti src;
    GLCRecti dest;

    set_clip(canvas, bbox, clip);
    glc_clear_mask(canvas->glc, GLC_MASK_A);
    glc_set_op(canvas->glc, GLC_OP_COPY);

    surface = canvas_get_image(&canvas->base, transparent->src_bitmap, FALSE);
    surface_to_image(canvas, surface, &image, 0);

    trans_surf = canvas_surf_to_trans_surf(&image, transparent->true_color);
    pixman_image_unref(surface);

    surface_to_image(canvas, trans_surf, &image, 1);
    SET_GLC_RECT(&dest, bbox);
    SET_GLC_RECT(&src, &transparent->src_area);
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, 1);

    pixman_image_unref(trans_surf);
    glc_flush(canvas->glc);
}

static inline void fill_common(GLCanvas *canvas, SpiceRect *bbox, SpiceClip *clip, SpiceQMask * mask, GLCOp op)
{
    GLCRect rect;

    set_clip(canvas, bbox, clip);
    set_mask(canvas, mask, bbox->left, bbox->top);
    glc_set_op(canvas->glc, op);
    SET_GLC_RECT(&rect, bbox);
    glc_fill_rect(canvas->glc, &rect);
}

static void gl_canvas_draw_whiteness(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceWhiteness *whiteness)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    fill_common(canvas, bbox, clip, &whiteness->mask, GLC_OP_SET);
}

static void gl_canvas_draw_blackness(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceBlackness *blackness)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    fill_common(canvas, bbox, clip, &blackness->mask, GLC_OP_CLEAR);
}

static void gl_canvas_draw_invers(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceInvers *invers)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    fill_common(canvas, bbox, clip, &invers->mask, GLC_OP_INVERT);
}

static void gl_canvas_draw_rop3(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceRop3 *rop3)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    pixman_image_t *d;
    pixman_image_t *s;
    GLCImage image;
    SpicePoint src_pos;
    uint8_t *data_opp;
    int src_stride;

    set_clip(canvas, bbox, clip);
    set_mask(canvas, &rop3->mask, bbox->left, bbox->top);

    glc_set_op(canvas->glc, GLC_OP_COPY);

    image.format = GLC_IMAGE_RGB32;
    image.width = bbox->right - bbox->left;
    image.height = bbox->bottom - bbox->top;

    image.pallet = NULL;

    d = pixman_image_create_bits(PIXMAN_x8r8g8b8, image.width, image.height, NULL, 0);
    if (d == NULL) {
        spice_critical("create surface failed");
        return;
    }
    image.pixels = (uint8_t *)pixman_image_get_data(d);
    image.stride = pixman_image_get_stride(d);

    glc_read_pixels(canvas->glc, bbox->left, bbox->top, &image);
    data_opp = copy_opposite_image(canvas, image.pixels,
                                   image.stride,
                                   pixman_image_get_height(d));
    memcpy(image.pixels, data_opp,
           image.stride * pixman_image_get_height(d));

    s = canvas_get_image(&canvas->base, rop3->src_bitmap, FALSE);
    src_stride = pixman_image_get_stride(s);
    if (src_stride > 0) {
        data_opp = copy_opposite_image(canvas, (uint8_t *)pixman_image_get_data(s),
                                       src_stride, pixman_image_get_height(s));
        memcpy((uint8_t *)pixman_image_get_data(s), data_opp,
               src_stride * pixman_image_get_height(s));
    }

    if (!rect_is_same_size(bbox, &rop3->src_area)) {
        pixman_image_t *scaled_s = canvas_scale_surface(s, &rop3->src_area, image.width,
                                                        image.height, rop3->scale_mode);
        pixman_image_unref(s);
        s = scaled_s;
        src_pos.x = 0;
        src_pos.y = 0;
    } else {
        src_pos.x = rop3->src_area.left;
        src_pos.y = rop3->src_area.top;
    }

    if (pixman_image_get_width(s) - src_pos.x < image.width ||
        pixman_image_get_height(s) - src_pos.y < image.height) {
        spice_critical("bad src bitmap size");
        return;
    }

    if (rop3->brush.type == SPICE_BRUSH_TYPE_PATTERN) {
        pixman_image_t *p = canvas_get_image(&canvas->base, rop3->brush.u.pattern.pat, FALSE);
        SpicePoint pat_pos;

        pat_pos.x = (bbox->left - rop3->brush.u.pattern.pos.x) % pixman_image_get_width(p);

        pat_pos.y = (bbox->top - rop3->brush.u.pattern.pos.y) % pixman_image_get_height(p);

        //for now (bottom-top)
        if (pat_pos.y < 0) {
            pat_pos.y = pixman_image_get_height(p) + pat_pos.y;
        }
        pat_pos.y = (image.height + pat_pos.y) % pixman_image_get_height(p);
        pat_pos.y = pixman_image_get_height(p) - pat_pos.y;

        do_rop3_with_pattern(rop3->rop3, d, s, &src_pos, p, &pat_pos);
        pixman_image_unref(p);
    } else {
        uint32_t color = (canvas->base.color_shift) == 8 ? rop3->brush.u.color :
                                                         canvas_16bpp_to_32bpp(rop3->brush.u.color);
        do_rop3_with_color(rop3->rop3, d, s, &src_pos, color);
    }

    pixman_image_unref(s);

    GLCRecti dest;
    GLCRecti src;
    dest.x = bbox->left;
    dest.y = bbox->top;

    image.pixels = copy_opposite_image(canvas, image.pixels, pixman_image_get_stride(d),
                                       pixman_image_get_height(d));

    src.x = src.y = 0;
    dest.width = src.width = image.width;
    dest.height = src.height = image.height;
    glc_draw_image(canvas->glc, &dest, &src, &image, 0, 1);
    pixman_image_unref(d);
}

static void gl_canvas_draw_stroke(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceStroke *stroke)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCPath path;

    set_clip(canvas, bbox, clip);
    glc_clear_mask(canvas->glc, GLC_MASK_A);
    set_op(canvas, stroke->fore_mode);
    set_brush(canvas, &stroke->brush);

    if (stroke->attr.flags & SPICE_LINE_FLAGS_STYLED) {
        spice_warning("SPICE_LINE_FLAGS_STYLED");
    }
    glc_set_line_width(canvas->glc, 1.0);

    path = get_path(canvas, stroke->path);
    glc_stroke_path(canvas->glc, path);
    glc_path_destroy(path);
}

static void gl_canvas_draw_text(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpiceText *text)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCRect rect;
    SpiceString *str;

    set_clip(canvas, bbox, clip);
    glc_clear_mask(canvas->glc, GLC_MASK_A);

    if (!rect_is_empty(&text->back_area)) {
        set_brush(canvas, &text->back_brush);
        set_op(canvas, text->back_mode);
        SET_GLC_RECT(&rect, bbox);
        glc_fill_rect(canvas->glc, &rect);
    }

    str = (SpiceString *)SPICE_GET_ADDRESS(text->str);
    set_brush(canvas, &text->fore_brush);
    set_op(canvas, text->fore_mode);
    if (str->flags & SPICE_STRING_FLAGS_RASTER_A1) {
        SpicePoint pos;
        pixman_image_t *mask = canvas_get_str_mask(&canvas->base, str, 1, &pos);
        _glc_fill_mask(canvas->glc, pos.x, pos.y,
                       pixman_image_get_width(mask),
                       pixman_image_get_height(mask),
                       pixman_image_get_stride(mask),
                       (uint8_t *)pixman_image_get_data(mask));
        pixman_image_unref(mask);
    } else if (str->flags & SPICE_STRING_FLAGS_RASTER_A4) {
        SpicePoint pos;
        pixman_image_t *mask = canvas_get_str_mask(&canvas->base, str, 4, &pos);
        glc_fill_alpha(canvas->glc, pos.x, pos.y,
                       pixman_image_get_width(mask),
                       pixman_image_get_height(mask),
                       pixman_image_get_stride(mask),
                       (uint8_t *)pixman_image_get_data(mask));

        pixman_image_unref(mask);
    } else if (str->flags & SPICE_STRING_FLAGS_RASTER_A8) {
        spice_warning("untested path A8 glyphs, doing nothing");
        if (0) {
            SpicePoint pos;
            pixman_image_t *mask = canvas_get_str_mask(&canvas->base, str, 8, &pos);
            glc_fill_alpha(canvas->glc, pos.x, pos.y,
                           pixman_image_get_width(mask),
                           pixman_image_get_height(mask),
                           pixman_image_get_stride(mask),
                           (uint8_t *)pixman_image_get_data(mask));
            pixman_image_unref(mask);
        }
    } else {
        spice_warning("untested path vector glyphs, doing nothing");
        if (0) {
            //draw_vector_str(canvas, str, &text->fore_brush, text->fore_mode);
        }
    }
    glc_flush(canvas->glc);
}

static void gl_canvas_clear(SpiceCanvas *spice_canvas)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    glc_clear(canvas->glc);
    glc_flush(canvas->glc);
}

static void gl_canvas_copy_bits(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceClip *clip, SpicePoint *src_pos)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    set_clip(canvas, bbox, clip);
    glc_clear_mask(canvas->glc, GLC_MASK_A);
    glc_set_op(canvas->glc, GLC_OP_COPY);
    glc_copy_pixels(canvas->glc, bbox->left, bbox->top, src_pos->x, src_pos->y,
                    bbox->right - bbox->left, bbox->bottom - bbox->top);
}

static void gl_canvas_read_bits(SpiceCanvas *spice_canvas, uint8_t *dest, int dest_stride, const SpiceRect *area)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCImage image;

    spice_return_if_fail(dest_stride > 0);

    image.format = GLC_IMAGE_RGB32;
    image.height = area->bottom - area->top;
    image.width = area->right - area->left;
    image.pixels = dest;
    image.stride = dest_stride;
    glc_read_pixels(canvas->glc, area->left, area->top, &image);
}

static void gl_canvas_group_start(SpiceCanvas *spice_canvas, QRegion *region)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCRect *glc_rects;
    GLCRect *now, *end;
    int num_rect;
    pixman_box32_t *rects;

    canvas_base_group_start(spice_canvas, region);

    rects = pixman_region32_rectangles(region, &num_rect);

    glc_rects = spice_new(GLCRect, num_rect);
    now = glc_rects;
    end = glc_rects + num_rect;

    for (; now < end; now++, rects++) {
        SET_GLC_BOX(now, rects);
    }
    glc_mask_rects(canvas->glc, num_rect, glc_rects, GLC_MASK_B);

    free(glc_rects);
}

static void gl_canvas_put_image(SpiceCanvas *spice_canvas, const SpiceRect *dest, const uint8_t *src_data,
                         uint32_t src_width, uint32_t src_height, int src_stride,
                         const QRegion *clip)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;
    GLCRecti src;
    GLCRecti gldest;
    GLCImage image;
    uint32_t i;

    spice_warn_if_fail(src_stride <= 0);

    glc_clip_reset(canvas->glc);

    if (clip) {
        int num_rects;
        pixman_box32_t *rects = pixman_region32_rectangles((pixman_region32_t *)clip,
                                                           &num_rects);
        GLCRect rect;
        if (num_rects == 0) {
            rect.x = rect.y = rect.width = rect.height = 0;
            glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_SET);
        } else {
            SET_GLC_BOX(&rect, rects);
            glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_SET);
            for (i = 1; i < num_rects; i++) {
                SET_GLC_BOX(&rect, rects + i);
                glc_clip_rect(canvas->glc, &rect, GLC_CLIP_OP_OR);
            }
        }
    }

    SET_GLC_RECT(&gldest, dest);
    src.x = src.y = 0;
    src.width = src_width;
    src.height = src_height;

    image.format = GLC_IMAGE_RGB32;
    image.width = src_width;
    image.height = src_height;
    if (src_stride < 0) {
        src_stride = -src_stride;
        image.pixels = (uint8_t *)src_data - (src_height - 1) * src_stride;
    } else {
        image.pixels = (uint8_t *)src_data;
    }
    image.stride = src_stride;
    image.pallet = NULL;
    glc_draw_image(canvas->glc, &gldest, &src, &image, 0, 1);

    glc_flush(canvas->glc);
}

static void gl_canvas_group_end(SpiceCanvas *spice_canvas)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;

    canvas_base_group_end(spice_canvas);
    glc_clear_mask(canvas->glc, GLC_MASK_B);
}

static int need_init = 1;
static SpiceCanvasOps gl_canvas_ops;

SpiceCanvas *gl_canvas_create(int width, int height, uint32_t format
                              , SpiceImageCache *bits_cache
#ifdef SW_CANVAS_CACHE
                              , SpicePaletteCache *palette_cache
#endif
                              , SpiceImageSurfaces *surfaces
                              , SpiceGlzDecoder *glz_decoder
                              , SpiceJpegDecoder *jpeg_decoder
                              , SpiceZlibDecoder *zlib_decoder
                           )
{
    GLCanvas *canvas;
    int init_ok;

    if (need_init) {
        return NULL;
    }
    canvas = spice_new0(GLCanvas, 1);

    if (!(canvas->glc = glc_create(width, height))) {
        goto error_1;
    }
    canvas->private_data = NULL;
    init_ok = canvas_base_init(&canvas->base, &gl_canvas_ops,
                               width, height, format
                               , bits_cache
#ifdef SW_CANVAS_CACHE
                               , palette_cache
#endif
                               , surfaces
                               , glz_decoder
                               , jpeg_decoder
                               , zlib_decoder
                               );
    if (!init_ok) {
        goto error_2;
    }

    return (SpiceCanvas *)canvas;

error_2:
    glc_destroy(canvas->glc, 0);
error_1:
    free(canvas);

    return NULL;
}

void gl_canvas_set_textures_lost(SpiceCanvas *spice_canvas,
                                 int textures_lost)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;

    canvas->textures_lost = textures_lost;
}

static void gl_canvas_destroy(SpiceCanvas *spice_canvas)
{
    GLCanvas *canvas = (GLCanvas *)spice_canvas;

    if (!canvas) {
        return;
    }
    canvas_base_destroy(&canvas->base);
    glc_destroy(canvas->glc, canvas->textures_lost);
    free(canvas->private_data);
    free(canvas);
}

void gl_canvas_init(void) //unsafe global function
{
    if (!need_init) {
        return;
    }
    need_init = 0;

    canvas_base_init_ops(&gl_canvas_ops);
    gl_canvas_ops.draw_fill = gl_canvas_draw_fill;
    gl_canvas_ops.draw_copy = gl_canvas_draw_copy;
    gl_canvas_ops.draw_opaque = gl_canvas_draw_opaque;
    gl_canvas_ops.copy_bits = gl_canvas_copy_bits;
    gl_canvas_ops.draw_text = gl_canvas_draw_text;
    gl_canvas_ops.draw_stroke = gl_canvas_draw_stroke;
    gl_canvas_ops.draw_rop3 = gl_canvas_draw_rop3;
    gl_canvas_ops.draw_blend = gl_canvas_draw_blend;
    gl_canvas_ops.draw_blackness = gl_canvas_draw_blackness;
    gl_canvas_ops.draw_whiteness = gl_canvas_draw_whiteness;
    gl_canvas_ops.draw_invers = gl_canvas_draw_invers;
    gl_canvas_ops.draw_transparent = gl_canvas_draw_transparent;
    gl_canvas_ops.draw_alpha_blend = gl_canvas_draw_alpha_blend;
    gl_canvas_ops.put_image = gl_canvas_put_image;
    gl_canvas_ops.clear = gl_canvas_clear;
    gl_canvas_ops.read_bits = gl_canvas_read_bits;
    gl_canvas_ops.group_start = gl_canvas_group_start;
    gl_canvas_ops.group_end = gl_canvas_group_end;
    gl_canvas_ops.destroy = gl_canvas_destroy;

    rop3_init();
}