u_draw_quad.h File Reference

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Functions
void	util_draw_vertex_buffer (struct pipe_context *pipe, struct pipe_buffer *vbuf, uint offset, uint num_attribs, uint num_verts, uint prim_type)
	Draw a simple vertex buffer / primitive.
void	util_draw_texquad (struct pipe_context *pipe, float x0, float y0, float x1, float y1, float z)
	Draw screen-aligned textured quad.

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Function Documentation

void util_draw_texquad	(	struct pipe_context *	pipe,
		float	x0,
		float	y0,
		float	x1,
		float	y1,
		float	z
	)

Draw screen-aligned textured quad.

Note: this function allocs/destroys a vertex buffer and isn't especially efficient.

Definition at line 81 of file u_draw_quad.c.

References pipe_buffer_create(), pipe_buffer_map(), pipe_buffer_reference(), pipe_buffer_unmap(), PIPE_BUFFER_USAGE_CPU_WRITE, PIPE_BUFFER_USAGE_VERTEX, PIPE_PRIM_TRIANGLE_FAN, pipe_context::screen, and util_draw_vertex_buffer().

{
   struct pipe_buffer *vbuf;
   uint numAttribs = 2, vertexBytes, i, j;

   vertexBytes = 4 * (4 * numAttribs * sizeof(float));

   /* XXX create one-time */
   vbuf = pipe_buffer_create(pipe->screen, 32,
                             PIPE_BUFFER_USAGE_VERTEX, vertexBytes);
   if (vbuf) {
      float *v = (float *) pipe_buffer_map(pipe->screen, vbuf,
                                           PIPE_BUFFER_USAGE_CPU_WRITE);
      if (v) {
         /*
          * Load vertex buffer
          */
         for (i = j = 0; i < 4; i++) {
            v[j + 2] = z;   /* z */
            v[j + 3] = 1.0; /* w */
            v[j + 6] = 0.0; /* r */
            v[j + 7] = 1.0; /* q */
            j += 8;
         }

         v[0] = x0;
         v[1] = y0;
         v[4] = 0.0; /*s*/
         v[5] = 0.0; /*t*/

         v[8] = x1;
         v[9] = y0;
         v[12] = 1.0;
         v[13] = 0.0;

         v[16] = x1;
         v[17] = y1;
         v[20] = 1.0;
         v[21] = 1.0;

         v[24] = x0;
         v[25] = y1;
         v[28] = 0.0;
         v[29] = 1.0;

         pipe_buffer_unmap(pipe->screen, vbuf);
         util_draw_vertex_buffer(pipe, vbuf, 0, PIPE_PRIM_TRIANGLE_FAN, 4, 2);
      }

      pipe_buffer_reference(pipe->screen, &vbuf, NULL);
   }
}

void util_draw_vertex_buffer	(	struct pipe_context *	pipe,
		struct pipe_buffer *	vbuf,
		uint	offset,
		uint	prim_type,
		uint	num_verts,
		uint	num_attribs
	)

Draw a simple vertex buffer / primitive.

Limited to float[4] vertex attribs, tightly packed.

Definition at line 41 of file u_draw_quad.c.

References assert, pipe_vertex_buffer::buffer, pipe_vertex_buffer::buffer_offset, pipe_context::draw_arrays, pipe_vertex_element::nr_components, PIPE_FORMAT_R32G32B32A32_FLOAT, pipe_vertex_buffer::pitch, pipe_context::set_vertex_buffers, pipe_context::set_vertex_elements, pipe_vertex_element::src_format, pipe_vertex_element::src_offset, and pipe_vertex_element::vertex_buffer_index.

{
   struct pipe_vertex_buffer vbuffer;
   struct pipe_vertex_element velements[PIPE_MAX_ATTRIBS];
   uint i;

   assert(num_attribs <= PIPE_MAX_ATTRIBS);

   /* tell pipe about the vertex buffer */
   vbuffer.buffer = vbuf;
   vbuffer.pitch = num_attribs * 4 * sizeof(float);  /* vertex size */
   vbuffer.buffer_offset = offset;
   pipe->set_vertex_buffers(pipe, 1, &vbuffer);

   /* tell pipe about the vertex attributes */
   for (i = 0; i < num_attribs; i++) {
      velements[i].src_offset = i * 4 * sizeof(float);
      velements[i].vertex_buffer_index = 0;
      velements[i].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
      velements[i].nr_components = 4;
   }
   pipe->set_vertex_elements(pipe, num_attribs, velements);

   /* draw */
   pipe->draw_arrays(pipe, prim_type, 0, num_verts);
}

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