[PATCH 09/20] glamor: Add glamor_program PolyPoint implementation

[Markus Wick]

Am 2014-03-19 06:09, schrieb Keith Packard:
> This accelerates poly point when possible by off-loading all geometry
> computation to the GPU.
> 
> Signed-off-by: Keith Packard <keithp at keithp.com>
> ---
>  glamor/glamor_polyops.c | 92 
> ++++++++++++++++++++++++++++++++++++++++++++++---
>  glamor/glamor_priv.h    |  3 ++
>  2 files changed, 91 insertions(+), 4 deletions(-)
> 
> diff --git a/glamor/glamor_polyops.c b/glamor/glamor_polyops.c
> index 1484d80..852e832 100644
> --- a/glamor/glamor_polyops.c
> +++ b/glamor/glamor_polyops.c
> @@ -27,17 +27,101 @@
>   */
> 
>  #include "glamor_priv.h"
> +#include "glamor_transform.h"
> +
> +static const glamor_facet glamor_facet_point = {
> +    .name = "poly_point",
> +    .vs_vars = "attribute vec2 primitive;\n",
> +    .vs_exec = GLAMOR_POS(gl_Position, primitive),
> +};
> 
>  static Bool
> -_glamor_poly_point(DrawablePtr pDrawable, GCPtr pGC, int mode, int 
> npt,
> +_glamor_poly_point(DrawablePtr drawable, GCPtr gc, int mode, int npt,
>                     DDXPointPtr ppt, Bool fallback)
>  {
> -    if (!fallback && glamor_ddx_fallback_check_gc(pGC)
> -        && glamor_ddx_fallback_check_pixmap(pDrawable))
> +    ScreenPtr screen = drawable->pScreen;
> +    glamor_screen_private *glamor_priv = 
> glamor_get_screen_private(screen);
> +    PixmapPtr pixmap = glamor_get_drawable_pixmap(drawable);
> +    glamor_program *prog = &glamor_priv->point_prog;
> +    glamor_pixmap_private *pixmap_priv;
> +    int off_x, off_y;
> +    GLshort *vbo_ppt;
> +    char *vbo_offset;
> +    int box_x, box_y;
> +
> +    if (!fallback && glamor_ddx_fallback_check_gc(gc)
> +        && glamor_ddx_fallback_check_pixmap(drawable))
>          return FALSE;
> 
> -    miPolyPoint(pDrawable, pGC, mode, npt, ppt);
> +    pixmap_priv = glamor_get_pixmap_private(pixmap);
> +    if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(pixmap_priv))
> +        goto bail;
> +
> +    glamor_get_context(glamor_priv);
> +
> +    if (prog->failed)
> +        goto bail_ctx;

I'd move glamor_get_context here. There is no need in calling get + put 
context when the shader isn't available.

> +
> +    if (!prog->prog) {
> +        if (!glamor_build_program(screen, prog,
> +                                  &glamor_facet_point,
> +                                  &glamor_fill_solid))
> +            goto bail_ctx;
> +    }
> +
> +    if (!glamor_use_program(pixmap, gc, prog, NULL))
> +        goto bail_ctx;
> +
> +    vbo_ppt = glamor_get_vbo_space(screen, npt * (2 * sizeof
> (INT16)), &vbo_offset);
> +    glEnableVertexAttribArray(GLAMOR_VERTEX_POS);
> +    glVertexAttribPointer(GLAMOR_VERTEX_POS, 2, GL_SHORT, GL_FALSE,
> 0, vbo_offset);
> +    if (mode == CoordModePrevious) {
> +        int n = npt;
> +        INT16 x = 0, y = 0;
> +        while (n--) {
> +            vbo_ppt[0] = (x += ppt->x);
> +            vbo_ppt[1] = (y += ppt->y);
> +            vbo_ppt += 2;
> +            ppt++;
> +        }
> +    } else
> +        memcpy(vbo_ppt, ppt, npt * (2 * sizeof (INT16)));
> +    glamor_put_vbo_space(screen);
> +
> +    glEnable(GL_SCISSOR_TEST);
> +
> +    glamor_pixmap_loop(pixmap_priv, box_x, box_y) {
> +        int nbox = RegionNumRects(gc->pCompositeClip);
> +        BoxPtr box = RegionRects(gc->pCompositeClip);
> +
> +        glamor_set_destination_drawable(drawable, box_x, box_y, TRUE,
> TRUE, prog->matrix_uniform, &off_x, &off_y);
> +
> +        while (nbox--) {
> +            glScissor(box->x1 + off_x,
> +                      box->y1 + off_y,
> +                      box->x2 - box->x1,
> +                      box->y2 - box->y1);
> +            box++;
> +            glDrawArrays(GL_POINTS, 0, npt);
> +        }
> +    }
> +
> +    glDisable(GL_SCISSOR_TEST);
> +    glDisable(GL_COLOR_LOGIC_OP);

Is it allowed to draw the same pixel more than once?
I wonder about overlapping boxes + logic ops.

> +    glDisableVertexAttribArray(GLAMOR_VERTEX_POS);
> +
> +    glamor_put_context(glamor_priv);
> +
> +    glamor_priv->state = RENDER_STATE;
> +    glamor_priv->render_idle_cnt = 0;
> +
> +    return TRUE;
> 
> +bail_ctx:
> +    glDisable(GL_COLOR_LOGIC_OP);
> +    glamor_put_context(glamor_priv);
> +bail:
> +    miPolyPoint(drawable, gc, mode, npt, ppt);
>      return TRUE;
>  }
> 
> diff --git a/glamor/glamor_priv.h b/glamor/glamor_priv.h
> index 1f6df3d..e4be4f3 100644
> --- a/glamor/glamor_priv.h
> +++ b/glamor/glamor_priv.h
> @@ -219,6 +219,9 @@ typedef struct glamor_screen_private {
>      GLint solid_prog;
>      GLint solid_color_uniform_location;
> 
> +    /* glamor point shader */
> +    glamor_program point_prog;
> +
>      /* vertext/elment_index buffer object for render */
>      GLuint vbo, ebo;
>      /** Next offset within the VBO that glamor_get_vbo_space() will 
> use. */