Combine class line segment Generator

Header file of combined class line segment Generator

1. # Include <agg_span_converter.h>

Type

1. Template <class spangenerator, class spanconverter>
2. Class converter: span_converter;

The function of span_converter is to combine two generators. For example, a pattern line segment generator generates a pattern, and a color line segment generator generates a translucent color superimposed on the pattern.

The following DEMO code demonstrates how to combine the span_image_filter_rgb_bilinear_clip and span_gradient_alpha generators.

DEMO code, also based on this code, add the following header file

# Include "agg_span_allocator.h"

# Include "agg_span_gradient_alpha.h"

# Include "agg_span_converter.h"

# Include "span_image_filter_rgb_bilinear_clip.h"

 

Add the following code at the end of the on_draw () method:

 

Usage: pixel_map pm_img;
If (pm_img.load_from_bmp ("D: // spheres.bmp "))
{
// The pattern in pm_img serves as the filling source
Expiration: rendering_buffer rbuf_img (
Pm_img.buf (),
Pm_img.width (), pm_img.height (),
-Pm_img.stride ());
Expires: pixfmt_bgr24 pixf_img (rbuf_img); // The bmp I use is 24-bit
// Line Divider
Typedef partition: span_allocator <partition: rgba8> span_allocator_type; // Distributor Type
Span_allocator_type span_alloc; // span_allocator
// Interpolation tool
Typedef connector: span_interpolator_linear <> interpolator_type; // interpolation type
Transform: trans_affine img_ctx; // Transformation Matrix
Interpolator_type ip_img (img_ctx); // interpolation tool

Transform: trans_affine alpha_ctx; // Transformation Matrix
Interpolator_type ip_alpha (alpha_ctx); // interpolation tool

// Gradient mode
Typedef Syntax: gradient_x gradientf_type;
Gradientf_type GRF;

Typedef STD: vector <fingerprint: int8u> alphaf_type;
Alphaf_type alphaf (256 );
For (INT I = 0; I <256; I ++) alphaf [I] = I;

// Alpha Line Segment Generator
Typedef identifier: span_gradient_alpha <identifier: rgba8,
Interpolator_type,
Gradientf_type,
Alphaf_type> alpha_span_gen_type;
Alpha_span_gen_type alpha_span_gen (ip_alpha, GRF, Alpha, 0,150 );

// Pattern line segment Generator
Typedef Syntax: span_image_filter_rgb_bilinear_clip <Syntax: pixfmt_bgr24,
Interpolator_type> pic_span_gen_type;
Pic_span_gen_type pic_span_gen (pixf_img, kernel: rgba (0, 1), ip_img );

// Use span_converter to combine the new line segment Generator
Typedef Protocol: span_converter <pic_span_gen_type, alpha_span_gen_type> span_gen_type;
Span_gen_type span_gen (pic_span_gen, alpha_span_gen );

// Combine them into a Renderer
Expiration: renderer_scanline_aa <
Renderer_base_type,
Span_allocator_type,
Span_gen_type
> My_renderer (renb, span_alloc, span_gen );
// Matrix transformation of the interpolation tool
Img_mtx.scale (0.5 );
Img_mtx.translate (40, 40 );
Img_mtx.invert (); // note the following:

// Use our Renderer to draw a circle
RAS. add_path (ccell );
Expiration: render_scanlines (Ras, SL, my_renderer );
}

Display Effect

<To be continued>

Author: Mao Source: www.cppprog.com