[Freeciv-Dev] Re: Using opengl in ftwl

[Raimar Falke <i-freeciv-lists@xxxxxxxxxxxxx>]

On Thu, Mar 24, 2005 at 07:25:16PM +0000, Per Inge Mathisen wrote:
> Here is a suggestion for changes to the ftwl backend API, attached as a
> diff. If you agree with these changes, I will start writing the OpenGL
> backend code to implement it; however I am not able to fix the higher
> level ftwl code (windowing etc).

> -void be_multiply_alphas(struct Sprite *dest_sprite,
> -                     const struct Sprite *src_sprite,
> -                     const struct ct_point *src_pos);

Easy.

> -void be_copy_osda_to_osda(struct osda *dest,
> -                       struct osda *src,
> -                       const struct ct_size *size,
> -                       const struct ct_point *dest_pos,
> -                       const struct ct_point *src_pos);
> +/* Copy canvas to back buffer */
> +void be_buffer_canvas(struct be_canvas *src,
> +                   const struct ct_size *size,
> +                   const struct ct_point *dest_pos,
> +                   const struct ct_point *src_pos);

So I can't copy a canvas to another one? Can't you implement this with
some magic?

Idea for implementation: the opengl backend records the drawing
operations done to an osda. If this osda is drawn to the big screen
these drawing actions are executed.

> -bool be_is_transparent_pixel(struct osda *osda, const struct ct_point *pos);

That is too hard. General OpenGL must support something for this case.

> +void be_flip_buffers(void); /* move back buffer to front buffer */

No idea what this should be.

> +void be_write_canvas_to_file(struct be_canvas *canvas, const char *filename);

Are you sure you can implement this?

        Raimar

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