diff options
| -rw-r--r-- | fastiv-io.c | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/fastiv-io.c b/fastiv-io.c index 5ce8ea3..90560fe 100644 --- a/fastiv-io.c +++ b/fastiv-io.c @@ -207,6 +207,7 @@ struct load_wuffs_frame_context { wuffs_base__io_buffer *src; ///< Wuffs source buffer wuffs_base__image_config cfg; ///< Wuffs image configuration wuffs_base__slice_u8 workbuf; ///< Work buffer for Wuffs + wuffs_base__frame_config last_fc; ///< Previous frame configuration uint32_t width; ///< Copied from cfg.pixcfg uint32_t height; ///< Copied from cfg.pixcfg cairo_format_t cairo_format; ///< Target format for surfaces @@ -222,7 +223,7 @@ struct load_wuffs_frame_context { static bool load_wuffs_frame(struct load_wuffs_frame_context *ctx, GError **error) { - wuffs_base__frame_config fc = {0}; + wuffs_base__frame_config fc = {}; wuffs_base__status status = wuffs_base__image_decoder__decode_frame_config(ctx->dec, &fc, ctx->src); if (status.repr == wuffs_base__note__end_of_data && ctx->result) @@ -310,6 +311,65 @@ load_wuffs_frame(struct load_wuffs_frame_context *ctx, GError **error) // Pixel data has been written, need to let Cairo know. cairo_surface_mark_dirty(surface); + // Single-frame images get a fast path, animations are are handled slowly: + if (wuffs_base__frame_config__index(&fc) > 0) { + // Copy the previous frame to a new surface. + cairo_surface_t *canvas = cairo_image_surface_create( + ctx->cairo_format, ctx->width, ctx->height); + int stride = cairo_image_surface_get_stride(canvas); + int height = cairo_image_surface_get_height(canvas); + memcpy(cairo_image_surface_get_data(canvas), + cairo_image_surface_get_data(ctx->result_tail), stride * height); + cairo_surface_mark_dirty(canvas); + + // Apply that frame's disposal method. + wuffs_base__rect_ie_u32 bounds = + wuffs_base__frame_config__bounds(&ctx->last_fc); + wuffs_base__color_u32_argb_premul bg = + wuffs_base__frame_config__background_color(&ctx->last_fc); + + double a = (bg >> 24) / 255., r = 0, g = 0, b = 0; + if (a) { + r = (uint8_t) (bg >> 16) / 255. / a; + g = (uint8_t) (bg >> 8) / 255. / a; + b = (uint8_t) (bg) / 255. / a; + } + + cairo_t *cr = cairo_create(canvas); + switch (wuffs_base__frame_config__disposal(&ctx->last_fc)) { + case WUFFS_BASE__ANIMATION_DISPOSAL__RESTORE_BACKGROUND: + cairo_rectangle(cr, bounds.min_incl_x, bounds.min_incl_y, + bounds.max_excl_x - bounds.min_incl_x, + bounds.max_excl_y - bounds.min_incl_y); + cairo_set_source_rgba(cr, r, g, b, a); + cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE); + cairo_fill(cr); + break; + case WUFFS_BASE__ANIMATION_DISPOSAL__RESTORE_PREVIOUS: + // TODO(p): Implement, it seems tricky. + // Might need another surface to keep track of the state. + break; + } + + // Paint the current frame over that, within its bounds. + bounds = wuffs_base__frame_config__bounds(&fc); + cairo_rectangle(cr, bounds.min_incl_x, bounds.min_incl_y, + bounds.max_excl_x - bounds.min_incl_x, + bounds.max_excl_y - bounds.min_incl_y); + cairo_clip(cr); + + cairo_set_operator(cr, + wuffs_base__frame_config__overwrite_instead_of_blend(&fc) + ? CAIRO_OPERATOR_SOURCE + : CAIRO_OPERATOR_OVER); + + cairo_set_source_surface(cr, surface, 0, 0); + cairo_paint(cr); + cairo_destroy(cr); + cairo_surface_destroy(surface); + surface = canvas; + } + if (ctx->meta_exif) cairo_surface_set_user_data(surface, &fastiv_io_key_exif, g_bytes_ref(ctx->meta_exif), (cairo_destroy_func_t) g_bytes_unref); @@ -334,6 +394,7 @@ load_wuffs_frame(struct load_wuffs_frame_context *ctx, GError **error) success = true; ctx->result_tail = surface; + ctx->last_fc = fc; fail: if (!success) { |