lazarus/components/aggpas/alpha_mask.dpr
mattias 36a2b1ea07 added aggpas
git-svn-id: trunk@21942 -
2009-10-01 12:24:32 +00:00

346 lines
6.5 KiB
ObjectPascal

//
// AggPas 2.4 RM3 Demo application
// Note: Press F1 key on run to see more info about this demo
//
// Paths: src;src\ctrl;src\svg;src\util;src\platform\win;expat-wrap
//
program
alpha_mask ;
uses
Math ,
agg_basics ,
agg_platform_support ,
agg_color ,
agg_pixfmt ,
agg_pixfmt_rgb ,
agg_pixfmt_gray ,
agg_rendering_buffer ,
agg_renderer_base ,
agg_renderer_scanline ,
agg_rasterizer_scanline_aa ,
agg_scanline ,
agg_scanline_u ,
agg_scanline_p ,
agg_render_scanlines ,
agg_ellipse ,
agg_path_storage ,
agg_conv_transform ,
agg_bounding_rect ,
agg_alpha_mask_u8 ,
agg_trans_affine ,
parse_lion_ ;
{$I agg_mode.inc }
const
flip_y = true;
var
g_path : path_storage;
g_colors : array[0..99 ] of aggclr;
g_path_idx : array[0..99 ] of unsigned;
g_npaths : unsigned;
g_x1 ,g_y1 ,g_x2 ,g_y2 ,
g_base_dx ,g_base_dy ,
g_angle ,g_scale ,
g_skew_x ,g_skew_y : double;
g_nclick : int;
g_alpha_mask_rbuf : rendering_buffer;
g_alpha_mask : alpha_mask_gray8;
g_rasterizer : rasterizer_scanline_aa;
type
the_application = object(platform_support )
m_alpha_size : unsigned;
m_alpha_buf : char_ptr;
m_alpha_rbuf : rendering_buffer;
constructor Construct(format_ : pix_format_e; flip_y_ : boolean );
destructor Destruct;
procedure generate_alpha_mask(cx ,cy : int );
procedure on_resize(sx ,sy : int ); virtual;
procedure on_draw; virtual;
procedure transform(width_ ,height_ ,x ,y : double );
procedure on_mouse_move (x ,y : int; flags : unsigned ); virtual;
procedure on_mouse_button_down(x ,y : int; flags : unsigned ); virtual;
procedure on_key(x ,y : int; key ,flags : unsigned ); virtual;
end;
{ _PARSE_LION_ }
procedure _parse_lion_;
begin
g_npaths:=parse_lion(@g_path ,@g_colors ,@g_path_idx );
bounding_rect(@g_path ,@g_path_idx ,0 ,g_npaths ,@g_x1 ,@g_y1 ,@g_x2 ,@g_y2 );
g_base_dx:=(g_x2 - g_x1 ) / 2.0;
g_base_dy:=(g_y2 - g_y1 ) / 2.0;
end;
{ CONSTRUCT }
constructor the_application.Construct;
begin
inherited Construct(format_ ,flip_y_ );
m_alpha_size:=0;
m_alpha_buf :=NIL;
_parse_lion_;
end;
{ DESTRUCT }
destructor the_application.Destruct;
begin
inherited Destruct;
agg_freemem(pointer(m_alpha_buf ) ,m_alpha_size );
end;
{ GENERATE_ALPHA_MASK }
procedure the_application.generate_alpha_mask;
var
pixf : pixel_formats;
rgba : aggclr;
rb : renderer_base;
r : renderer_scanline_aa_solid;
sl : scanline_p8;
ell : ellipse;
i : unsigned;
begin
agg_freemem(pointer(m_alpha_buf ) ,m_alpha_size );
m_alpha_size:=cx * cy;
agg_getmem(pointer(m_alpha_buf ) ,m_alpha_size );
g_alpha_mask_rbuf.attach(int8u_ptr(m_alpha_buf ) ,cx ,cy ,cx );
pixfmt_gray8(pixf ,@g_alpha_mask_rbuf );
rb.Construct(@pixf );
r.Construct (@rb );
sl.Construct;
rgba.ConstrInt(0 );
rb.clear (@rgba );
ell.Construct;
for i:=0 to 9 do
begin
ell.init(
Random($7fff ) mod cx ,
Random($7fff ) mod cy ,
Random($7fff ) mod 100 + 20 ,
Random($7fff ) mod 100 + 20 ,100 );
g_rasterizer.add_path(@ell );
rgba.ConstrInt(Random($7fff ) and $FF ,Random($7fff ) and $FF );
r.color_ (@rgba );
render_scanlines(@g_rasterizer ,@sl ,@r );
end;
sl.Destruct;
end;
{ ON_RESIZE }
procedure the_application.on_resize;
begin
generate_alpha_mask(sx ,sy );
end;
{ ON_DRAW }
procedure the_application.on_draw;
var
width_ ,height_ : int;
pixf : pixel_formats;
rb : renderer_base;
r : renderer_scanline_aa_solid;
sl : scanline_u8_am;
rgba : aggclr;
trans : conv_transform;
mtx : trans_affine;
tat : trans_affine_translation;
tas : trans_affine_scaling;
tar : trans_affine_rotation;
taw : trans_affine_skewing;
begin
width_ :=rbuf_window._width;
height_:=rbuf_window._height;
// Initialize structures
pixfmt_bgr24(pixf ,rbuf_window );
rb.Construct(@pixf );
r.Construct (@rb );
sl.Construct(@g_alpha_mask );
rgba.ConstrInt(255 ,255 ,255 );
rb.clear (@rgba );
// Transform lion
mtx.Construct;
tat.Construct(-g_base_dx ,-g_base_dy );
mtx.multiply (@tat );
tas.Construct(g_scale ,g_scale );
mtx.multiply (@tas );
tar.Construct(g_angle + pi );
mtx.multiply (@tar );
taw.Construct(g_skew_x / 1000.0 ,g_skew_y / 1000.0 );
mtx.multiply (@taw );
tat.Construct(width_ / 2 ,height_ / 2 );
mtx.multiply (@tat );
// This code renders the lion
trans.Construct(@g_path ,@mtx );
render_all_paths(@g_rasterizer ,@sl ,@r ,@trans ,@g_colors ,@g_path_idx ,g_npaths );
// Free AGG resources
sl.Destruct;
end;
{ TRANSFORM }
procedure the_application.transform;
begin
x:=x - width_ / 2;
y:=y - height_ / 2;
g_angle:=ArcTan2(y ,x );
g_scale:=Sqrt(y * y + x * x ) / 100.0;
end;
{ ON_MOUSE_MOVE }
procedure the_application.on_mouse_move;
begin
on_mouse_button_down(x ,y ,flags );
end;
{ ON_MOUSE_BUTTON_DOWN }
procedure the_application.on_mouse_button_down;
var
width_ ,height_ : int;
begin
if flags and mouse_left <> 0 then
begin
width_ :=rbuf_window._width;
height_:=rbuf_window._height;
transform(width_ ,height_ ,x ,y );
force_redraw;
end;
if flags and mouse_right <> 0 then
begin
g_skew_x:=x;
g_skew_y:=y;
force_redraw;
end;
end;
{ ON_KEY }
procedure the_application.on_key;
begin
if key = key_f1 then
message_(
'Alpha-mask is a simple method of clipping and masking polygons to a number'#13 +
'of other arbitrary polygons. Alpha mask is a buffer that is mixed to the '#13 +
'scanline container and controls the Anti-Aliasing values in it. It''s not the '#13 +
'perfect mechanism of clipping, but it allows you not only to clip the polygons, '#13 +
'but also to change the opacity in certain areas, i.e., the clipping can be '#13 +
'translucent. '#13#13 +
'How to play with:'#13#13 +
'Press and drag the left mouse button to scale and rotate the lion.'#13 +
'Resize the window to generate new alpha-mask.'#13 +
'Use the right mouse button to skew the lion.' +
#13#13'Note: F2 key saves current "screenshot" file in this demo''s directory. ' );
end;
VAR
app : the_application;
BEGIN
// Rendering
g_path.Construct;
g_npaths:=0;
g_x1:=0;
g_y1:=0;
g_x2:=0;
g_y2:=0;
g_base_dx:=0;
g_base_dy:=0;
g_angle:=0;
g_scale:=1.0;
g_skew_x:=0;
g_skew_y:=0;
g_nclick:=0;
g_alpha_mask_rbuf.Construct;
g_alpha_mask.Construct(@g_alpha_mask_rbuf );
g_rasterizer.Construct;
// App
app.Construct(pix_format_bgr24 ,flip_y );
app.caption_ ('AGG Example. Lion with Alpha-Masking (F1-Help)' );
if app.init(512 ,400 ,window_resize ) then
app.run;
app.Destruct;
// Free
g_path.Destruct;
g_alpha_mask_rbuf.Destruct;
g_rasterizer.Destruct;
END.