/**

  * $Id: render.c,v 1.19 2007-01-25 08:18:03 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"

 struct pvr2_render_buffer front_buffer;

 struct pvr2_render_buffer back_buffer;

 typedef struct pvr2_bgplane_packed {

         uint32_t        poly_cfg, poly_mode;

         uint32_t        texture_mode;

         float           x1, y1, z1;

         uint32_t          colour1;

         float           x2, y2, z2;

         uint32_t          colour2;

         float           x3, y3, z3;

         uint32_t          colour3;

 } *pvr2_bgplane_packed_t;

 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();

 }

 gboolean pvr2_render_init( void )

 {

     front_buffer.render_addr = -1;

     back_buffer.render_addr = -1;

 }

 /**

  * Invalidate any caching on the supplied address. Specifically, if it falls

  * within either the front buffer or back buffer, flush the buffer back to

  * PVR2 ram (note that front buffer flush may be corrupt under some

  * circumstances).

  */

 gboolean pvr2_render_buffer_invalidate( sh4addr_t address )

 {

     address = address & 0x1FFFFFFF;

     if( front_buffer.render_addr != -1 &&

 	front_buffer.render_addr <= address &&

 	(front_buffer.render_addr + front_buffer.size) > address ) {

 	pvr2_render_buffer_copy_to_sh4( &front_buffer, FALSE );

 	front_buffer.render_addr = -1;

 	return TRUE;

     } else if( back_buffer.render_addr != -1 &&

 	       back_buffer.render_addr <= address &&

 	       (back_buffer.render_addr + back_buffer.size) > address ) {

 	pvr2_render_buffer_copy_to_sh4( &back_buffer, TRUE );

 	back_buffer.render_addr = -1;

 	return TRUE;

     }

     return FALSE;

 }

 /**

  * Display a rendered frame if one is available.

  * @param address An address in PVR ram (0500000 range).

  * @return TRUE if a frame was available to be displayed, otherwise false.

  */

 gboolean pvr2_render_display_frame( uint32_t address )

 {

     if( front_buffer.render_addr == address ) {

 	/* Current front buffer is already displayed, so do nothing

 	 * and tell the caller that all is well.

 	 */

 	return TRUE;

     }

     if( back_buffer.render_addr == address ) {

 	/* The more useful case - back buffer is to be displayed. Swap

 	 * the buffers 

 	 */

 	display_driver->display_back_buffer();

 	front_buffer = back_buffer;

 	back_buffer.render_addr = -1;

 	return TRUE;

     }

     return FALSE;

 }	

 /**

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

  */

 static void pvr2_render_prepare_context( sh4addr_t render_addr, 

 					 uint32_t width, uint32_t height,

 					 uint32_t colour_format, 

 					 float bgplanez, float nearz,

 					 gboolean texture_target )

 {

     /* Select and initialize the render context */

     display_driver->set_render_format( width, height, colour_format, texture_target );

     if( pvr2_render_font_list == -1 ) {

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

     }

     if( back_buffer.render_addr != -1 && 

 	back_buffer.render_addr != render_addr ) {

 	/* There's a current back buffer, and we're rendering somewhere else -

 	 * flush the back buffer back to vram and start a new back buffer

 	 */

 	pvr2_render_buffer_copy_to_sh4( &back_buffer, TRUE );

     }

     if( front_buffer.render_addr == render_addr ) {

 	/* In case we've been asked to render to the current front buffer -

 	 * invalidate the front buffer and render to the back buffer, ensuring

 	 * we swap at the next frame display.

 	 */

 	front_buffer.render_addr = -1;

     }

     back_buffer.render_addr = render_addr;

     back_buffer.width = width;

     back_buffer.height = height;

     back_buffer.colour_format = colour_format;

     back_buffer.size = width * height * colour_format_bytes[colour_format];

     /* Setup the display model */

     glDrawBuffer(GL_BACK);

     glShadeModel(GL_SMOOTH);

     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

     glViewport( 0, 0, width, height );

     glMatrixMode(GL_PROJECTION);

     glLoadIdentity();

     glOrtho( 0, width, height, 0, bgplanez, -(nearz+1) );

     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( )

 {

     struct tile_descriptor *tile_desc =

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

     uint32_t render_addr = MMIO_READ( PVR2, RENDER_ADDR1 );

     gboolean render_to_tex;

     if( render_addr & 0x01000000 ) {

 	render_addr = (render_addr & 0x00FFFFFF) + PVR2_RAM_BASE_INT;

 	/* Heuristic - if we're rendering to the interlaced region we're

 	 * probably creating a texture rather than rendering actual output.

 	 * We can optimise for this case a little

 	 */

 	render_to_tex = TRUE;

 	WARN( "Render to texture not supported properly yet" );

     } else {

 	render_addr = (render_addr & 0x00FFFFFF) + PVR2_RAM_BASE;

 	render_to_tex = FALSE;

     }

     float bgplanez = MMIO_READF( PVR2, RENDER_FARCLIP );

     uint32_t render_mode = MMIO_READ( PVR2, RENDER_MODE );

     int width = 640; /* FIXME - get this from the tile buffer */

     int height = 480;

     int colour_format = pvr2_render_colour_format[render_mode&0x07];

     float maxz = pvr2_render_find_maximum_z();

     pvr2_render_prepare_context( render_addr, width, height, colour_format, 

 				 bgplanez, maxz, render_to_tex );

     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, width, height, bgplane_mode );

     pvr2_render_tilebuffer( width, height, clip_x, clip_y, 

 			    clip_x + clip_width, clip_y + clip_height );

     /* Post-render cleanup and update */

     /* Add frame, fps, etc data */

     //glDrawGrid( width, height );

     glPrintf( 4, 16, "Frame %d", pvr2_get_frame_count() );

     /* Generate end of render event */

     asic_event( EVENT_PVR_RENDER_DONE );

     DEBUG( "Rendered frame %d", pvr2_get_frame_count() );

 }