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Equal (typed)

SWF Action
Action Category: 
Action Details: 
Action Identifier: 
Action Structure: 
Action Length: 
0 byte(s)
Action Stack: 
pop 2 (a), push 1 (b)
Action Operation: 
a1 := pop();
a2 := pop();
if(is_int(a1) && is_int(a2)) {
  i1 := (int)a1;
  i2 := (int)a2;
  r := i2 == i1;    // compare integers
else if(is_numeric(a1) && is_numeric(a2)) {
  f1 := (float)a1;
  f2 := (float)a2;
  r := f2 == f1;    // compare floating points, likely to always return false!
else {
  s1 := (string)a1;
  s2 := (string)a2;
  r := s2 == s1;    // compare characters, case sensitive
Action Flash Version: 

Pop two integers, floats or strings, compute whether they are equal and push the Boolean result back on the stack.

The != operator can be simulated using the Logical Not action right after the Equal (typed).

If a mix set of types is popped from the stack, conventional conversions occur. Strings may be transformed to numbers and numbers to strings as with the untyped Equal operator.


Tag Info
Tag Number: 
Tag Type: 
Tag Flash Version: 
Brief Description: 

Since version 8, this tag is required and needs to be the very first tag in the movie. It is used as a way to better handle security within the Flash Player.

Tag Structure: 
struct swf_fileattributes {
	swf_tag			f_tag;		/* 69 */
	unsigned		f_reserved : 3;
	unsigned		f_has_metadata : 1;
	unsigned		f_allow_abc : 1;	/* since V9.0 */
	unsigned		f_suppress_cross_domain_caching : 1;	/* since V9.0 */
	unsigned		f_swf_relative_urls : 1;	/* since V9.0 */
	unsigned		f_use_network : 1;
	unsigned		f_reserved : 24;

The FileAttributes tag is new to version 8. It must be present in all movies version 8 and over. It must be the very first tag in the SWF movie. It should be unique (other instances will be ignored.)

The f_has_metadata flag shall be set to 1 whenever the movie includes a Metadata tag.

The f_allow_abc flag shall be set to 1 to give the player the right to execute DoABC scripts (this is a version 9 flag, in version 8, keep it set to 0.)

The f_suppress_cross_domain_caching must have some effect over the caching of some things... (version 9+)

The f_swf_relative_urls means that URLs specified ...


Tag Info
Tag Number: 
Tag Type: 
Tag Flash Version: 
Brief Description: 

An edit text enables the end users to enter text in a Flash window.

Tag Structure: 
struct swf_defineedittext {
	swf_tag			f_tag;		/* 37 */
	unsigned short		f_edit_id;
	swf_rect		f_rect;
	unsigned		f_edit_has_text : 1;
	unsigned		f_edit_word_wrap : 1;
	unsigned		f_edit_multiline : 1;
	unsigned		f_edit_password : 1;
	unsigned		f_edit_readonly : 1;
	unsigned		f_edit_has_color : 1;
	unsigned		f_edit_has_max_length : 1;
	unsigned		f_edit_has_font : 1;
	if(version >= 6) {
		unsigned		f_edit_reserved : 1;
		unsigned		f_edit_auto_size : 1;
	else {
		unsigned		f_edit_reserved : 2;
	unsigned		f_edit_has_layout : 1;
	unsigned		f_edit_no_select : 1;
	unsigned		f_edit_border : 1;
	unsigned		f_edit_reserved : 1;
	unsigned		f_edit_html : 1;
	unsigned		f_edit_use_outlines : 1;
	if(f_edit_has_font) {
		unsigned short		f_edit_font_id_ref;
		unsigned short		f_edit_font_height;
	if(f_edit_has_color) {
		swf_rgba		f_edit_color;
	if(f_edit_has_max_length) {
		unsigned short		f_edit_max_length;
	if(f_edit_has_layout) {
		unsigned char		f_edit_align;
		unsigned short		f_edit_left_margin;
		unsigned short		f_edit_right_margin;
		signed short		f_edit_indent;
		signed short		f_edit_leading;
	string			f_edit_variable_name;
	if(f_edit_has_text) {
		string			f_edit_initial_text;

Additional interactivity has been added in V4.0 of the SWF format. This is given by the use of edit boxes offering the end users a way to enter text as if the SWF movie was in fact an interactive form.

The text is defined in a variable (accessible in action scripts). It can be dynamically assigned and retrieved. It is legal to have an empty string as the variable name (not dynamically accessible).

Since version 8, the text drawn by a DefineEditText tag can be tweaked by adding a CSMTextSettings tag.

The f_edit_word_wrap flag will be set to true (1) in order to have words going beyond the ...


Tag Info
Tag Number: 
Tag Type: 
Tag Flash Version: 
Brief Description: 

Define a list of glyphs using shapes and other font metric information.

Tag Structure: 
struct swf_definefont2 {
	swf_tag			f_tag;		/* 48 or 75 */
	unsigned short		f_font2_id;
	unsigned		f_font2_has_layout : 1;
	if(version >= 6) {
		unsigned	f_font2_reserved : 1;
		if(version >= 7) {
			unsigned	f_font2_small_text : 1;
		unsigned	f_font2_reserved : 1;
	else {
		unsigned	f_font2_shiftjis : 1;
		unsigned	f_font2_unicode : 1;
		unsigned	f_font2_ansii : 1;
	unsigned		f_font2_wide_offsets : 1;
	unsigned		f_font2_wide : 1;	/* always 1 in v6.x+ */
	unsigned		f_font2_italic : 1;
	unsigned		f_font2_bold : 1;
	if(version >= 6) {
		unsigned char	f_font2_language;
	else {
		unsigned char	f_font2_reserved;
	unsigned char		f_font2_name_length;
	unsigned char		f_font2_name[f_font2_name_length];
	unsigned short		f_font2_glyphs_count;
	if(f_font2_wide_offsets) {
		unsigned long		f_font2_offsets[f_font2_glyphs_count];
		unsigned long		f_font2_map_offset;
	else {
		unsigned short		f_font2_offsets[f_font2_glyphs_count];
		unsigned short		f_font2_map_offset;
	swf_shape		f_font2_shapes[f_font2_glyphs_count];
	if(f_font_info_wide) {
		unsigned short		f_font2_map[f_font2_glyphs_count];
	else {
		unsigned char		f_font2_map[f_font2_glyphs_count];
	if(f_font2_has_layout) {
		signed short		f_font2_ascent;
		signed short		f_font2_descent;
		signed short		f_font2_leading_height;
		signed short		f_font2_advance[f_font2_glyphs_count];
		swf_rect		f_font2_bounds[f_font2_glyphs_count];
		signed short		f_font2_kerning_count;
		swf_kerning		f_font2_kerning[f_font2_kerning_count];
/* DefineFont3 is the same as DefineFont2 */
typedef struct swf_definefont2 swf_definefont3;

It is common to use the DefineFont2 tag in order to create an array of shapes later re-used to draw strings of text on the screen. This tag must be used whenever a DefineEditText references a font; and in that case it is suggested you include a full description of the font with layouts.

The array of glyphs must be ordered in ascending order (the smaller glyph number saved first; thus 'a' must be saved before 'b', etc.).

All the characters should be defined in a 1024x1024 square (in pixels) to be drawn with the best possible quality. This square is called the EM square.

The ...

Appendix A — The geometry in SWF — Gradient Fills

It is possible in SWF to use gradient fills. The gradient definitions are pretty raw and require you to draw large objects (that you can scale down later if you wish). A radial fill will usually be used to draw a round corner or a big & smooth dot. A linear fill can be used to draw objects which go from one color to another. The linear fill goes from left to right by default. It can be rotation as required though. Yet, in either case what is drawn in the shape object needs to be at the right scale and in the right direction. This may not always prove easy to deal with!

Appendix A — The geometry in SWF — Matrix

The coordinates are often transformed with the use of a matrix. The matrix is similar to a transformation matrix in Postscript. It includes a set of scaling factors, rotation angles and translations.

When only the scaling factors are used (no rotation) then these are ratios as one would expect. If a rotation is also applied, then the scaling ratios will be affected accordingly.

Appendix A — The geometry in SWF — Coordinates

The most common and simple geometric information are the object coordinates on the output screen. These are defined in TWIPs. There are 20 twips per pixels. Note that an embedded SWF file can be enlarged and/or reduced thus changing this basic scaling factor. To have exactly 20 twips per pixel you must ensure that the EMBED and/or OBJECT tags use a WIDTH and HEIGHT with exactly the same value as in the rectangle defined in the SWF header file divided by 20.

SWF Envelope (swf_envelope)

SWF Structure Info
Tag Flash Version: 
SWF Structure: 
struct swf_envelope {
	unsigned long		f_position;
	unsigned short		f_volume_left;
	unsigned short		f_volume_right;

When playing back a sound effect it is possible to modulate the sound to generate different effects (such as a fade in and out). The following defines the stereo volume of the sound.

The position is always given as if the sample data was defined with a rate of 44,100 bytes per seconds. For instance, the sample number 1 in a sound effect with a sample rate of 5.5K is given as position 8 in the envelope. All of these positions should be within the f_in_point and f_out_point.

SWF Condition (swf_condition)

SWF Structure Info
Tag Flash Version: 
SWF Structure: 
struct swf_condition {
	unsigned short		f_condition_length;1
	unsigned		f_condition_key : 7;
	unsigned		f_condition_menu_leave : 1;
	unsigned		f_condition_menu_enter : 1;
	unsigned		f_condition_pointer_release_ouside : 1;
	unsigned		f_condition_pointer_drag_enter : 1;
	unsigned		f_condition_pointer_drag_leave : 1;
	unsigned		f_condition_pointer_release_inside : 1;
	unsigned		f_condition_pointer_push : 1;
	unsigned		f_condition_pointer_leave : 1;
	unsigned		f_condition_pointer_enter : 1;
	swf_action		f_action_record[variable];
  • 1. The number of actions is variable, the f_condition_length parameter indicates the number of bytes and can be used to skip one condition and all of its actions at once. The action array must always be terminated by an End action entry (i.e 0x00).

A condition is defined in a DefineButton2 tag. It is a record of conditions. The record terminates when the size of the current (i.e. last) condition is zero. The length of that condition can be deduced from the total size of the tag minus the offset where the condition starts. Conditions are similar to events.

The f_key field represents a key code since version 4. The following table gives the code equivalence. Note that 0 means no key.

SWF Any Filter (swf_any_filter)

SWF Structure Info
Tag Flash Version: 
SWF Structure: 
/* the filter type */
struct swf_filter_type {
	unsigned char	f_type;

struct swf_filter_glow {
	swf_filter_type	f_type;		/* 0, 2, 3, 4 or 7 */
	if(f_type == GradientGlow || f_type == GradientBevel) {
		unsigned char		f_count;
	else {
		f_count = 1;
	swf_rgba		f_rgba[f_count];
	if(f_type == Bevel) {
		swf_rgba		f_highlight_rgba[f_count];
	if(f_type == GradientGlow || f_type == GradientBevel) {
		unsigned char		f_position[f_count];
	signed long fixed	f_blur_horizontal;
	signed long fixed	f_blur_vertical;
	if(f_type != Glow) {
		signed long fixed	f_radian_angle;
		signed long fixed	f_distance;
	signed short fixed	f_strength;
	unsigned		f_inner_shadow : 1;
	unsigned		f_knock_out : 1;
	unsigned		f_composite_source : 1;
	if(f_type == Bevel) {
		unsigned		f_on_top : 1;
	else {
		unsigned		f_reserved : 1;
	if(f_type == GradientGlow || f_type == GradientBevel) {
		unsigned		f_passes : 4;
	else {
		unsigned		f_reserved : 4;

struct swf_filter_blur {
	swf_filter_type		f_type;	/* 1 */
	unsigned long fixed	f_blur_horizontal;
	unsigned long fixed	f_blur_vertical;
	unsigned		f_passes : 5;
	unsigned		f_reserved : 3;

struct swf_filter_convolution {
	swf_filter_type	f_type;		/* 5 */
	unsigned char	f_columns;
	unsigned char	f_rows;
	long float	f_divisor;
	long float	f_bias;
	long float	f_weights[f_columns × f_rows];
	swf_rgba	f_default_color;
	unsigned	f_reserved : 6;
	unsigned	f_clamp : 1;
	unsigned	f_preserve_alpha : 1;

struct swf_filter_colormatrix {
	swf_filter_type	f_type;		/* 6 */
	long float	f_matrix[20];

struct swf_any_filter {
	swf_filter_type			f_fitler_type;
	swf_filter_blur			f_filter_blur;
	swf_filter_colormatrix		f_filter_colormatrix;
	swf_filter_convolution		f_filter_convolution;
	swf_filter_glow			f_filter_glow;

A filter defines how to transform the objects it is attached to. The first byte is the filter type. The data following depend on the type. Because each filter is much different, they are defined in separate structures. You can attach a filter to an object using an ActionScript or the PlaceObject3 tag.

The following describes the different filters available since version 8.

Value Name Version
0 Drop Shadow 8