/**************************************************************************
 * 
 * Copyright 2007 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.
 * 
 **************************************************************************/

#include "main/imports.h"
#include "main/context.h"
#include "main/extensions.h"
#include "main/macros.h"

#include "pipe/p_context.h"
#include "pipe/p_defines.h"

#include "st_context.h"
#include "st_extensions.h"


/*
 * Compute floor(log_base_2(n)).
 * If n < 0 return -1.
 */
static int
logbase2( int n )
{
   GLint i = 1;
   GLint log2 = 0;

   if (n < 0)
      return -1;

   if (n == 0)
      return 0;

   while ( n > i ) {
      i *= 2;
      log2++;
   }
   if (i != n) {
      return log2 - 1;
   }
   else {
      return log2;
   }
}


void st_init_limits(struct st_context *st)
{
   struct pipe_context *pipe = st->pipe;
   GLcontext *ctx = st->ctx;
   uint w, h, d;

   ctx->Const.MaxTextureImageUnits
      = ctx->Const.MaxTextureCoordUnits
      = pipe->get_param(pipe, PIPE_CAP_MAX_TEXTURE_IMAGE_UNITS);

   pipe->max_texture_size(pipe, PIPE_TEXTURE_2D, &w, &h, &d);
   ctx->Const.MaxTextureLevels = logbase2(w) + 1;
   ctx->Const.MaxTextureRectSize = w;

   pipe->max_texture_size(pipe, PIPE_TEXTURE_3D, &w, &h, &d);
   ctx->Const.Max3DTextureLevels = logbase2(d) + 1;

   pipe->max_texture_size(pipe, PIPE_TEXTURE_CUBE, &w, &h, &d);
   ctx->Const.MaxCubeTextureLevels = logbase2(w) + 1;
   
   ctx->Const.MaxDrawBuffers = MAX2(1, pipe->get_param(pipe, PIPE_CAP_MAX_RENDER_TARGETS));

}


/**
 * XXX this needs careful review
 */
void st_init_extensions(struct st_context *st)
{
   struct pipe_context *pipe = st->pipe;
   GLcontext *ctx = st->ctx;

   /*
    * Extensions that are supported by all Gallium drivers:
    */
   ctx->Extensions.ARB_fragment_program = GL_TRUE;
   ctx->Extensions.ARB_texture_cube_map = GL_TRUE;
   ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
   ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
   ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
   ctx->Extensions.ARB_vertex_program = GL_TRUE;
   ctx->Extensions.ARB_vertex_buffer_object = GL_TRUE;

   ctx->Extensions.EXT_blend_color = GL_TRUE;
   ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
   ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
   ctx->Extensions.EXT_blend_logic_op = GL_TRUE;
   ctx->Extensions.EXT_blend_minmax = GL_TRUE;
   ctx->Extensions.EXT_blend_subtract = GL_TRUE;
   ctx->Extensions.EXT_framebuffer_object = GL_TRUE;
   ctx->Extensions.EXT_fog_coord = GL_TRUE;
   ctx->Extensions.EXT_multi_draw_arrays = GL_TRUE;
   ctx->Extensions.EXT_pixel_buffer_object = GL_TRUE;
   ctx->Extensions.EXT_point_parameters = GL_TRUE;
   ctx->Extensions.EXT_secondary_color = GL_TRUE;
   ctx->Extensions.EXT_stencil_wrap = GL_TRUE;
   ctx->Extensions.EXT_texture_env_add = GL_TRUE;
   ctx->Extensions.EXT_texture_env_combine = GL_TRUE;
   ctx->Extensions.EXT_texture_env_dot3 = GL_TRUE;
   ctx->Extensions.EXT_texture_lod_bias = GL_TRUE;

   ctx->Extensions.NV_blend_square = GL_TRUE;
   ctx->Extensions.NV_texgen_reflection = GL_TRUE;


   /*
    * Extensions that depend on the driver/hardware:
    */
   if (pipe->get_param(pipe, PIPE_CAP_MAX_RENDER_TARGETS) > 1) {
      ctx->Extensions.ARB_draw_buffers = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_GLSL) > 1) {
      ctx->Extensions.ARB_fragment_shader = GL_TRUE;
      ctx->Extensions.ARB_vertex_shader = GL_TRUE;
      ctx->Extensions.ARB_shader_objects = GL_TRUE;
      ctx->Extensions.ARB_shading_language_100 = GL_TRUE;
      ctx->Extensions.ARB_shading_language_120 = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_NPOT_TEXTURES)) {
      ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
      ctx->Extensions.NV_texture_rectangle = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_MAX_TEXTURE_IMAGE_UNITS) > 1) {
      ctx->Extensions.ARB_multitexture = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_TWO_SIDED_STENCIL) > 1) {
      ctx->Extensions.ATI_separate_stencil = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_S3TC) > 1) {
      ctx->Extensions.ARB_texture_compression = GL_TRUE;
      ctx->Extensions.EXT_texture_compression_s3tc = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_ANISOTROPIC_FILTER)) {
      ctx->Extensions.EXT_texture_filter_anisotropic = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_POINT_SPRITE)) {
      ctx->Extensions.ARB_point_sprite = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_OCCLUSION_QUERY) > 1) {
      ctx->Extensions.ARB_occlusion_query = GL_TRUE;
   }

   if (pipe->get_param(pipe, PIPE_CAP_TEXTURE_SHADOW_MAP) > 1) {
      ctx->Extensions.ARB_depth_texture = GL_TRUE;
      ctx->Extensions.ARB_shadow = GL_TRUE;
      /*ctx->Extensions.ARB_shadow_ambient = GL_TRUE;*/
   }

}