/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

#ifndef ST_CONTEXT_H
#define ST_CONTEXT_H

#include "mtypes.h"
#include "pipe/p_state.h"


struct st_context;
struct st_region;
struct st_texture_object;
struct st_texture_image;
struct st_fragment_program;
struct draw_context;
struct draw_stage;
struct cso_cache;
struct cso_blend;

#define ST_NEW_MESA                    0x1 /* Mesa state has changed */
#define ST_NEW_FRAGMENT_PROGRAM        0x2
#define ST_NEW_VERTEX_PROGRAM          0x4


struct st_state_flags {
   GLuint mesa;
   GLuint st;
};

struct st_tracked_state {
   const char *name;
   struct st_state_flags dirty;
   void (*update)( struct st_context *st );
};




struct st_context
{
   GLcontext *ctx;

   struct pipe_context *pipe;

   struct draw_context *draw;  /**< For selection/feedback */
   struct draw_stage *feedback_stage;  /**< For FL_FEEDBACK rendermode */
   struct draw_stage *selection_stage;  /**< For GL_SELECT rendermode */

   /* Eventually will use a cache to feed the pipe with
    * create/bind/delete calls to constant state objects.  Not yet
    * though, we just shove random objects across the interface.  
    */
   struct {
      const struct cso_alpha_test      *alpha_test;
      const struct cso_blend           *blend;
      const struct cso_sampler         *sampler[PIPE_MAX_SAMPLERS];
      const struct cso_depth_stencil   *depth_stencil;
      const struct cso_rasterizer      *rasterizer;
      const struct cso_fragment_shader *fs;
      const struct cso_vertex_shader   *vs;

      struct pipe_blend_color  blend_color;
      struct pipe_clear_color_state clear_color;
      struct pipe_clip_state clip;
      struct pipe_constant_buffer constants[2];
      struct pipe_feedback_state feedback;
      struct pipe_framebuffer_state framebuffer;
      struct pipe_mipmap_tree *texture[PIPE_MAX_SAMPLERS];
      struct pipe_poly_stipple poly_stipple;
      struct pipe_scissor_state scissor;
      struct pipe_viewport_state viewport;
   } state;

   struct {
      struct st_tracked_state tracked_state[2];
   } constants;

   struct {
      struct gl_fragment_program *fragment_program;
   } cb;

   struct {
      GLuint frontbuffer_dirty:1;
   } flags;

   char vendor[100];
   char renderer[100];

   /** Can we access the front/back color buffers as pipe_regions?
    * We can't with the Xlib driver...
    * This is a hack that should be fixed someday.
    */
   GLboolean haveFramebufferRegions;

   /* State to be validated:
    */
   struct st_tracked_state **atoms;
   GLuint nr_atoms;

   struct st_state_flags dirty;

   GLfloat polygon_offset_scale; /* ?? */

   /** Mapping from VERT_RESULT_x to post-transformed vertex slot */
   const GLuint *vertex_result_to_slot;

   struct st_vertex_program *vp;    /**< Currently bound vertex program */
   struct st_fragment_program *fp;  /**< Currently bound fragment program */

   /**
    * Buffer object which stores the ctx->Current.Attrib[] values.
    * Used for vertex array drawing when we we need an attribute for
    * which there's no enabled array.
    */
   struct pipe_buffer_handle *default_attrib_buffer;

   struct cso_cache *cache;
};


/* Need this so that we can implement Mesa callbacks in this module.
 */
static INLINE struct st_context *st_context(GLcontext *ctx)
{
   return ctx->st;
}


extern void st_init_driver_functions(struct dd_function_table *functions);



#define Y_0_TOP 1
#define Y_0_BOTTOM 2

static INLINE GLuint
st_fb_orientation(const struct gl_framebuffer *fb)
{
   if (fb && fb->Name == 0) {
      /* Drawing into a window (on-screen buffer).
       *
       * Negate Y scale to flip image vertically.
       * The NDC Y coords prior to viewport transformation are in the range
       * [y=-1=bottom, y=1=top]
       * Hardware window coords are in the range [y=0=top, y=H-1=bottom] where
       * H is the window height.
       * Use the viewport transformation to invert Y.
       */
      return Y_0_TOP;
   }
   else {
      /* Drawing into user-created FBO (very likely a texture).
       *
       * For textures, T=0=Bottom, so by extension Y=0=Bottom for rendering.
       */
      return Y_0_BOTTOM;
   }
}


#endif
