/**

 * $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 );

}