图案填充失败
#include "platform/agg_platform_support.h"
#include "agg_basics.h"
#include "agg_rendering_buffer.h"
#include "agg_pixfmt_rgb.h"
#include "agg_alpha_mask_u8.h"
#include "agg_pixfmt_amask_adaptor.h"
#include "agg_rasterizer_scanline_aa.h"
#include "agg_scanline_u.h"
#include "agg_renderer_scanline.h"
#include "agg_ellipse.h"
#include "agg_conv_contour.h"
#include "agg_conv_stroke.h"
#include "agg_conv_dash.h"
#include "agg_conv_transform.h"
#include "platform/win32/agg_win32_bmp.h"
#include "agg_span_allocator.h"
#include "agg_span_image_filter_rgb.h"
#include "agg_span_interpolator_trans.h"
#include "agg_span_interpolator_persp.h"
#include "agg_span_interpolator_linear.h"
enum { flip_y = true};
class the_application : public agg::platform_support
{
public:
the_application(agg::pix_format_e format, bool flip_y):
agg::platform_support(format,flip_y)
{}
virtual ~the_application()
{
}
virtual void on_init(){}
virtual void on_draw()
{
unsigned i;
//renderer buffer
agg::rendering_buffer rbuf = this->rbuf_window();
//renderers
agg::pixfmt_bgr24 pixf(rbuf);//底层像素渲染对象，对渲染内存进行包装了
typedef agg::renderer_base<agg::pixfmt_bgr24> ren_base_type;//底层渲染器
ren_base_type ren_base(pixf);
ren_base.clear( agg::rgba8(255,255,255) );//清除buffer背景色
typedef agg::renderer_scanline_aa_solid<ren_base_type> renderer_scanline_type;//高层渲染器
renderer_scanline_type ren_scanline(ren_base);
//装载图案作为生成span生成器的source
agg::pixel_map pm_img;//可以load进bitmap
pm_img.load_from_bmp("d://hello.bmp");
//构建图案的renderer
agg::rendering_buffer rbuf_img( pm_img.buf(), pm_img.width(), pm_img.height(),pm_img.stride() );
agg::pixfmt_rgb24 pixf_img(rbuf_img);
//线段分配器
typedef agg::span_allocator<agg::rgba8> span_allocator_type;
span_allocator_type span_alloc;
//透视变换的插值器
typedef agg::span_interpolator_persp_lerp<> span_interp_type;
const double offset(0);
const double scale(0.1);
double src[8] = {offset,offset,
offset+pixf_img.width()*scale, offset,
offset+pixf_img.width()*scale, offset+pixf_img.height()*scale,
offset, offset+pixf_img.height()*scale};
double dest[8] = {0,0-180,
pixf.width(), 0-180,
pixf.width(), pixf.height()-180,
0, pixf.height()-180};
span_interp_type span_interp(src,dest);
//span生成器,使用图案作为span生成器
typedef agg::span_image_filter_rgb_bilinear_clip<agg::pixfmt_rgb24,span_interp_type> span_gen_type;
span_gen_type span_gen(pixf_img, agg::rgba8(255,255,255), span_interp);
//组合成渲染器
agg::renderer_scanline_aa< ren_base_type, span_allocator_type, span_gen_type > img_renderer(ren_base, span_alloc, span_gen);
//vertex source
agg::ellipse ell(0,0, 120, 90);//定义一个圆vertex source
//vertex source 仿射变换
agg::trans_affine imx;
imx.translate(150, 150);
typedef agg::conv_transform<agg::ellipse> ell_ct_type;
ell_ct_type ctell(ell, imx);
//轮廓
typedef agg::conv_contour<ell_ct_type> ell_cc_type;
ell_cc_type ccell(ctell);
//
typedef agg::conv_stroke<ell_ct_type> ell_cs_type;
ell_cs_type csccell(ctell);
csccell.width(1);//con_stroke的width属性决定线宽度
agg::rasterizer_scanline_aa<> ras;//Polygon rasterizer, which including a clipper
agg::scanline_u8 sl;//非封装扫描线容器,rasterizer use it to render the render_buffer
//使用图案填充
ras.add_path(ctell);
agg::render_scanlines( ras, sl, img_renderer );
//椭圆轮廓线
ras.add_path(csccell);//添加路径
ren_scanline.color( agg::rgba8(50,40,23) );
agg::render_scanlines( ras, sl, ren_scanline );//ras使用sl中的span渲染ren_scanline
}
};
int agg_main(int argc, char* argv[])
{
the_application app(agg::pix_format_bgr24, flip_y);
app.caption("My AGG Demo");
if(app.init(300, 300, agg::window_resize ))
{
app.run();
}
return 1;
}
摘自：http://blog.csdn.net/erikliu/article/details/6232764
提出如下的几点疑问：
1）是否跟AGG的版本有关，目前使用了2.4，2.5版本无效！！
2) 是否跟图片的像素有关？？
3）是否有例子支持，源码下没有任何的例子支持！！