/**

  * $Id: render.c,v 1.24 2007-02-11 10:09:32 nkeynes Exp $

  *

  * PVR2 Renderer support. This part is primarily

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  */

 #include "pvr2/pvr2.h"

 #include "asic.h"

 int pvr2_render_font_list = -1;

 int pvr2_render_trace = 0;

 int glPrintf( int x, int y, const char *fmt, ... )

 {

     va_list ap;     /* our argument pointer */

     char buf[256];

     int len;

     if (fmt == NULL)    /* if there is no string to draw do nothing */

         return;

     va_start(ap, fmt); 

     len = vsnprintf(buf, sizeof(buf), fmt, ap);

     va_end(ap);

     glPushAttrib(GL_LIST_BIT);

     glDisable( GL_DEPTH_TEST );

     glDisable( GL_BLEND );

     glDisable( GL_TEXTURE_2D );

     glDisable( GL_ALPHA_TEST );

     glDisable( GL_CULL_FACE );

     glListBase(pvr2_render_font_list - 32);

     glColor3f( 1.0, 1.0, 1.0 );

     glRasterPos2i( x, y );

     glCallLists(len, GL_UNSIGNED_BYTE, buf);

     glPopAttrib();

     return len;

 }

 void glDrawGrid( int width, int height )

 {

     int i;

     glDisable( GL_DEPTH_TEST );

     glLineWidth(1);

     glBegin( GL_LINES );

     glColor4f( 1.0, 1.0, 1.0, 1.0 );

     for( i=32; i<width; i+=32 ) {

 	glVertex3f( i, 0.0, 3.0 );

 	glVertex3f( i,height-1, 3.0 );

     }

     for( i=32; i<height; i+=32 ) {

 	glVertex3f( 0.0, i, 3.0 );

 	glVertex3f( width, i, 3.0 );

     }

     glEnd();

 }

 /**

  * Prepare the OpenGL context to receive instructions for a new frame.

  */

 static void pvr2_render_prepare_context( render_buffer_t buffer,

 					 float bgplanez, float nearz ) 

 {

     /* Select and initialize the render context */

     display_driver->set_render_target(buffer);

     if( pvr2_render_font_list == -1 ) {

 	pvr2_render_font_list = video_glx_load_font( "-*-helvetica-*-r-normal--16-*-*-*-p-*-iso8859-1");

     }

     pvr2_check_palette_changed();

     /* Setup the display model */

     glShadeModel(GL_SMOOTH);

     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

     glMatrixMode(GL_PROJECTION);

     glLoadIdentity();

     glOrtho( 0, buffer->width, buffer->height, 0, -bgplanez, -nearz );

     glMatrixMode(GL_MODELVIEW);

     glLoadIdentity();

     glCullFace( GL_BACK );

     glEnable( GL_BLEND );

     /* Clear out the buffers */

     glDisable( GL_SCISSOR_TEST );

     glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

     glClearDepth(0);

     glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

 }

 /**

  * Render a complete scene into the OpenGL back buffer.

  * Note: this will probably need to be broken up eventually once timings are

  * determined.

  */

 void pvr2_render_scene( render_buffer_t buffer )

 {

     struct tile_descriptor *tile_desc =

 	(struct tile_descriptor *)mem_get_region(PVR2_RAM_BASE + MMIO_READ( PVR2, RENDER_TILEBASE ));

     float bgplanez = 1/MMIO_READF( PVR2, RENDER_FARCLIP );

     pvr2_render_prepare_context( buffer, bgplanez, 0 );

     int clip_x = MMIO_READ( PVR2, RENDER_HCLIP ) & 0x03FF;

     int clip_y = MMIO_READ( PVR2, RENDER_VCLIP ) & 0x03FF;

     int clip_width = ((MMIO_READ( PVR2, RENDER_HCLIP ) >> 16) & 0x03FF) - clip_x + 1;

     int clip_height= ((MMIO_READ( PVR2, RENDER_VCLIP ) >> 16) & 0x03FF) - clip_y + 1;

     /* Fog setup goes here? */

     /* Render the background plane */

     uint32_t bgplane_mode = MMIO_READ(PVR2, RENDER_BGPLANE);

     uint32_t *display_list = 

 	(uint32_t *)mem_get_region(PVR2_RAM_BASE + MMIO_READ( PVR2, RENDER_POLYBASE ));

     uint32_t *bgplane = display_list + (((bgplane_mode & 0x00FFFFFF)) >> 3) ;

     render_backplane( bgplane, buffer->width, buffer->height, bgplane_mode );

     pvr2_render_tilebuffer( buffer->width, buffer->height, clip_x, clip_y, 

 			    clip_x + clip_width, clip_y + clip_height );

     DEBUG( "Rendered frame %d to %08X", pvr2_get_frame_count(), buffer->address );

 }