/**

 * $Id: render.c,v 1.10 2006-06-27 09:32:09 nkeynes Exp $

 *

 * PVR2 Renderer support. This is where the real work happens.

 *

 * 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"

#define POLY_COLOUR_PACKED 0x00000000

#define POLY_COLOUR_FLOAT 0x00000010

#define POLY_COLOUR_INTENSITY 0x00000020

#define POLY_COLOUR_INTENSITY_PREV 0x00000030

static int pvr2_poly_vertexes[4] = { 3, 4, 6, 8 };

static int pvr2_poly_type[4] = { GL_TRIANGLES, GL_QUADS, GL_TRIANGLE_STRIP, GL_TRIANGLE_STRIP };

static int pvr2_poly_depthmode[8] = { GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL,

				      GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, 

				      GL_ALWAYS };

static int pvr2_poly_srcblend[8] = { 

    GL_ZERO, GL_ONE, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR,

    GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA, 

    GL_ONE_MINUS_DST_ALPHA };

static int pvr2_poly_dstblend[8] = {

    GL_ZERO, GL_ONE, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR,

    GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_DST_ALPHA,

    GL_ONE_MINUS_DST_ALPHA };

static int pvr2_poly_texblend[4] = {

    GL_REPLACE, GL_BLEND, GL_DECAL, GL_MODULATE };

static int pvr2_render_colour_format[8] = {

    COLFMT_ARGB1555, COLFMT_RGB565, COLFMT_ARGB4444, COLFMT_ARGB1555,

    COLFMT_RGB888, COLFMT_ARGB8888, COLFMT_ARGB8888, COLFMT_ARGB4444 };

#define POLY_STRIP_TYPE(poly) ( pvr2_poly_type[((poly->command)>>18)&0x03] )

#define POLY_STRIP_VERTEXES(poly) ( pvr2_poly_vertexes[((poly->command)>>18)&0x03] )

#define POLY_DEPTH_MODE(poly) ( pvr2_poly_depthmode[poly->poly_cfg>>29] )

#define POLY_DEPTH_WRITE(poly) ((poly->poly_cfg&0x04000000) == 0 )

#define POLY_TEX_WIDTH(poly) ( 1<< (((poly->poly_mode >> 3) & 0x07 ) + 3) )

#define POLY_TEX_HEIGHT(poly) ( 1<< (((poly->poly_mode) & 0x07 ) + 3) )

#define POLY_BLEND_SRC(poly) ( pvr2_poly_srcblend[(poly->poly_mode) >> 29] )

#define POLY_BLEND_DEST(poly) ( pvr2_poly_dstblend[((poly->poly_mode)>>26)&0x07] )

#define POLY_TEX_BLEND(poly) ( pvr2_poly_texblend[((poly->poly_mode) >> 6)&0x03] )

#define POLY_COLOUR_TYPE(poly) ( poly->command & 0x00000030 )

/**

 * Describes a rendering buffer that's actually held in GL, for when we need

 * to fetch the bits back to vram.

 */

typedef struct pvr2_render_buffer {

    sh4addr_t render_addr; /* The actual address rendered to in pvr ram */

    uint32_t size; /* Length of rendering region in bytes */

    int width, height;

    int colour_format;

} *pvr2_render_buffer_t;

struct pvr2_render_buffer front_buffer;

struct pvr2_render_buffer back_buffer;

struct tile_descriptor {

    uint32_t header[6];

    struct tile_pointers {

	uint32_t tile_id;

	uint32_t opaque_ptr;

	uint32_t opaque_mod_ptr;

	uint32_t trans_ptr;

	uint32_t trans_mod_ptr;

	uint32_t punchout_ptr;

    } tile[0];

};

/* Textured polygon */

struct pvr2_poly {

    uint32_t command;

    uint32_t poly_cfg; /* Bitmask */

    uint32_t poly_mode; /* texture/blending mask */

    uint32_t texture; /* texture data */

    float alpha;

    float red;

    float green;

    float blue;

};

struct pvr2_specular_highlight {

    float base_alpha;

    float base_red;

    float base_green;

    float base_blue;

    float offset_alpha;

    float offset_red;

    float offset_green;

    float offset_blue;

};

struct pvr2_vertex_packed {

    uint32_t command;

    float x, y, z;

    float s,t;

    uint32_t colour;

    float f;

};

struct pvr2_vertex_float {

    uint32_t command;

    float x,y,z;

    float a, r, g, b;

};

union pvr2_vertex {

    struct pvr2_vertex_packed pack;

    struct pvr2_vertex_float flt;

};

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;

void pvr2_render_copy_to_sh4( pvr2_render_buffer_t buffer, 

			      gboolean backBuffer );

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 );

    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;

}

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_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_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_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,

					 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_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, -4 );

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    glCullFace( GL_BACK );

    /* Clear out the buffers */

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

    glClearDepth(bgplanez);

    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

}

static void pvr2_dump_display_list( uint32_t * display_list, uint32_t length )

{

    uint32_t i;

    gboolean vertex = FALSE;

    for( i =0; i<length>>2; i++ ) {

	if( (i % 8) == 0 ) {

	    if( i != 0 )

		fprintf( stderr, "\n" );

	    fprintf( stderr, "%08X:", i*4 );

	    if( display_list[i] == 0xE0000000 ||

		display_list[i] == 0xF0000000 ) 

		vertex = TRUE;

	    else vertex = FALSE;

	}

	if( vertex && (i%8) > 0 && (i%8) < 4 )

	    fprintf( stderr, " %f", ((float *)display_list)[i] );

	else

	    fprintf( stderr, " %08X", display_list[i] );

    }

    fprintf( stderr, "\n" );

}

static void pvr2_render_display_list( uint32_t *display_list, uint32_t length )

{

    uint32_t *cmd_ptr = display_list;

    int strip_length = 0, vertex_count = 0;

    int colour_type;

    gboolean textured = FALSE;

    gboolean shaded = FALSE;

    struct pvr2_poly *poly;

    if( pvr2_render_trace ) {

	fprintf( stderr, "-------- %d\n", pvr2_get_frame_count() );

	pvr2_dump_display_list( display_list, length );

    }

    while( cmd_ptr < display_list+(length>>2) ) {

	unsigned int cmd = *cmd_ptr >> 24;

	switch( cmd ) {

	case PVR2_CMD_POLY_OPAQUE:

	case PVR2_CMD_POLY_TRANS:

	case PVR2_CMD_POLY_PUNCHOUT:

	    poly = (struct pvr2_poly *)cmd_ptr;

	    if( poly->command & PVR2_POLY_TEXTURED ) {

		uint32_t addr = PVR2_TEX_ADDR(poly->texture);

		int width = POLY_TEX_WIDTH(poly);

		int height = POLY_TEX_HEIGHT(poly);

		glEnable( GL_TEXTURE_2D );

		texcache_get_texture( addr, width, height, poly->texture );

		textured = TRUE;

		glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, POLY_TEX_BLEND(poly) );

	    } else {

		textured = FALSE;

		glDisable( GL_TEXTURE_2D );

	    }

	    glBlendFunc( POLY_BLEND_SRC(poly), POLY_BLEND_DEST(poly) );

	    if( poly->command & PVR2_POLY_SPECULAR ) {

		/* Second block expected */

	    }

	    if( POLY_DEPTH_WRITE(poly) ) {

		glEnable( GL_DEPTH_TEST );

		glDepthFunc( POLY_DEPTH_MODE(poly) );

	    } else {

		glDisable( GL_DEPTH_TEST );

	    }

	    switch( (poly->poly_cfg >> 27) & 0x03 ) {

	    case 0:

	    case 1:

		glDisable( GL_CULL_FACE );

		break;

	    case 2:

		glEnable( GL_CULL_FACE );

		glFrontFace( GL_CW );

		break;

	    case 3:

		glEnable( GL_CULL_FACE );

		glFrontFace( GL_CCW );

	    }

	    strip_length = POLY_STRIP_VERTEXES( poly );

	    colour_type = POLY_COLOUR_TYPE( poly );

	    vertex_count = 0;

	    if( poly->command & PVR2_POLY_SHADED ) {

		shaded = TRUE;

	    } else {

		shaded = FALSE;

	    }

	    if( poly->poly_mode & PVR2_POLY_MODE_TEXALPHA ) {

		glDisable( GL_BLEND );

	    } else {

		glEnable( GL_BLEND );

	    }

	    break;

	case PVR2_CMD_MOD_OPAQUE:

	case PVR2_CMD_MOD_TRANS:

	    /* TODO */

	    break;

	case PVR2_CMD_END_OF_LIST:

	    break;

	case PVR2_CMD_VERTEX_LAST:

	case PVR2_CMD_VERTEX:

	    if( vertex_count == 0 ) {

		glBegin( GL_TRIANGLE_STRIP );

	    }

	    vertex_count++;

	    struct pvr2_vertex_packed *vertex = (struct pvr2_vertex_packed *)cmd_ptr;

	    if( textured ) {

		glTexCoord2f( vertex->s, vertex->t );

		if( shaded || vertex_count == 1) {

		    switch( colour_type ) {

		    case POLY_COLOUR_PACKED:

			glColor4ub( vertex->colour >> 16, vertex->colour >> 8,

				    vertex->colour, vertex->colour >> 24 );

			break;

		    }

		}

	    } else {

		if( shaded || vertex_count == 1 ) {

		    switch( colour_type ) {

		    case POLY_COLOUR_PACKED:

			glColor4ub( vertex->colour >> 16, vertex->colour >> 8,

				    vertex->colour, vertex->colour >> 24 );

			break;

		    case POLY_COLOUR_FLOAT: 

			{

			    struct pvr2_vertex_float *v = (struct pvr2_vertex_float *)cmd_ptr;

			    glColor4f( v->r, v->g, v->b, v->a );

			}

			break;

		    }

		}

	    }

	    glVertex3f( vertex->x, vertex->y, vertex->z );

	    if( cmd == PVR2_CMD_VERTEX_LAST ) {

		glEnd();

		vertex_count = 0;

	    }

	    break;

	default:

	    ERROR( "Unhandled command %08X in display list", *cmd_ptr );

	    pvr2_dump_display_list( display_list, length );

	    return;

	}

	cmd_ptr += 8; /* Next record */

    }

}

#define MIN3( a,b,c ) ((a) < (b) ? ( (a) < (c) ? (a) : (c) ) : ((b) < (c) ? (b) : (c)) )

#define MAX3( a,b,c ) ((a) > (b) ? ( (a) > (c) ? (a) : (c) ) : ((b) > (c) ? (b) : (c)) )

/**

 * Render the background plane as best we can. Unfortunately information

 * is a little scant, to say the least.

 */

void pvr2_render_draw_backplane( uint32_t mode, uint32_t *poly )

{

    if( (mode >> 24) == 0x01 ) {

	/* Packed colour. I think */

	pvr2_bgplane_packed_t bg = (pvr2_bgplane_packed_t)poly;

	if( bg->colour1 != bg->colour2 || bg->colour2 != bg->colour3 ) {

	    WARN( "Multiple background colours specified. Confused" );

	}

	float x1 = MIN3( bg->x1, bg->x2, bg->x3 );

	float y1 = MIN3( bg->y1, bg->y2, bg->y3 );

	float x2 = MAX3( bg->x1, bg->x2, bg->x3 );

	float y2 = MAX3( bg->y1, bg->y2, bg->y3 );

	float z = MIN3( bg->z1, bg->z2, bg->z3 );

	glDisable( GL_TEXTURE_2D );

	glDisable( GL_DEPTH_TEST );

	glColor3ub( (uint8_t)(bg->colour1 >> 16), (uint8_t)(bg->colour1 >> 8), 

		    (uint8_t)bg->colour1 );

	glBegin( GL_QUADS );

	glVertex3f( x1, y1, z );

	glVertex3f( x2, y1, z );

	glVertex3f( x2, y2, z );

	glVertex3f( x1, y2, z );

	glEnd();

    } else {

	WARN( "Unknown bgplane mode: %08X", mode );

	fwrite_dump( poly, 48, stderr );

    }

}

/**

 * 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, TILEBASE ));

    uint32_t render_addr = MMIO_READ( PVR2, RENDADDR1 );

    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, BGPLANEZ );

    uint32_t render_mode = MMIO_READ( PVR2, RENDMODE );

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

    int height = 480;

    int colour_format = pvr2_render_colour_format[render_mode&0x07];

    pvr2_render_prepare_context( render_addr, width, height, colour_format, 

				 bgplanez, render_to_tex );

    uint32_t *display_list = 

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

    uint32_t display_length = *display_list++;

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

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

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

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

    if( clip_x == 0 && clip_y == 0 && clip_width == width && clip_height == height ) {

	glDisable( GL_SCISSOR_TEST );

    } else {

	glEnable( GL_SCISSOR_TEST );

	glScissor( clip_x, clip_y, clip_width, clip_height );

    }

    /* Fog setup goes here */

    /* Render the background plane */

    uint32_t bgplane_mode = MMIO_READ(PVR2, BGPLANE);

    uint32_t *bgplane = display_list + (((bgplane_mode & 0x00FFFFFF)) >> 3) - 1;

    pvr2_render_draw_backplane( bgplane_mode, bgplane );

    /* Render the display list */

    pvr2_render_display_list( display_list, display_length );

    /* Post-render cleanup and update */

    /* Add frame, fps, etc data */

    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() );

}

/**

 * Flush the indicated render buffer back to PVR. Caller is responsible for

 * tracking whether there is actually anything in the buffer.

 *

 * @param buffer A render buffer indicating the address to store to, and the

 * format the data needs to be in.

 * @param backBuffer TRUE to flush the back buffer, FALSE for 

 * the front buffer.

 */

void pvr2_render_copy_to_sh4( pvr2_render_buffer_t buffer, 

			      gboolean backBuffer )

{

    if( buffer->render_addr == -1 )

	return;

    GLenum type, format = GL_RGBA;

    int size = buffer->width * buffer->height;

    switch( buffer->colour_format ) {

    case COLFMT_RGB565: 

	type = GL_UNSIGNED_SHORT_5_6_5; 

	format = GL_RGB; 

	size <<= 1;

	break;

    case COLFMT_RGB888: 

	type = GL_UNSIGNED_INT; 

	format = GL_RGB;

	size = (size<<1)+size;

	break;

    case COLFMT_ARGB1555: 

	type = GL_UNSIGNED_SHORT_5_5_5_1; 

	size <<= 1;

	break;

    case COLFMT_ARGB4444: 

	type = GL_UNSIGNED_SHORT_4_4_4_4; 

	size <<= 1;

	break;

    case COLFMT_ARGB8888: 

	type = GL_UNSIGNED_INT_8_8_8_8; 

	size <<= 2;

	break;

    }

    if( backBuffer ) {

	glFinish();

	glReadBuffer( GL_BACK );

    } else {

	glReadBuffer( GL_FRONT );

    }

    if( buffer->render_addr & 0xFF000000 == 0x04000000 ) {

	/* Interlaced buffer. Go the double copy... :( */

	char target[size];

	glReadPixels( 0, 0, buffer->width, buffer->height, format, type, target );

	pvr2_vram64_write( buffer->render_addr, target, size );

    } else {

	/* Regular buffer - go direct */

	char *target = mem_get_region( buffer->render_addr );

	glReadPixels( 0, 0, buffer->width, buffer->height, format, type, target );

    }

}

/**

 * Copy data from PVR ram into the GL render buffer. 

 *

 * @param buffer A render buffer indicating the address to read from, and the

 * format the data is in.

 * @param backBuffer TRUE to write the back buffer, FALSE for 

 * the front buffer.

 */

void pvr2_render_copy_from_sh4( pvr2_render_buffer_t buffer, 

				gboolean backBuffer )

{

    if( buffer->render_addr == -1 )

	return;

    GLenum type, format = GL_RGBA;

    int size = buffer->width * buffer->height;

    switch( buffer->colour_format ) {

    case COLFMT_RGB565: 

	type = GL_UNSIGNED_SHORT_5_6_5; 

	format = GL_RGB; 

	size <<= 1;

	break;

    case COLFMT_RGB888: 

	type = GL_UNSIGNED_INT; 

	format = GL_RGB;

	size = (size<<1)+size;

	break;

    case COLFMT_ARGB1555: 

	type = GL_UNSIGNED_SHORT_5_5_5_1; 

	size <<= 1;

	break;

    case COLFMT_ARGB4444: 

	type = GL_UNSIGNED_SHORT_4_4_4_4; 

	size <<= 1;

	break;

    case COLFMT_ARGB8888: 

	type = GL_UNSIGNED_INT_8_8_8_8; 

	size <<= 2;

	break;

    }

    if( backBuffer ) {

	glDrawBuffer( GL_BACK );

    } else {

	glDrawBuffer( GL_FRONT );

    }

    glRasterPos2i( 0, 0 );

    if( buffer->render_addr & 0xFF000000 == 0x04000000 ) {

	/* Interlaced buffer. Go the double copy... :( */

	char target[size];

	pvr2_vram64_read( target, buffer->render_addr, size );

	glDrawPixels( buffer->width, buffer->height, 

		      format, type, target );

    } else {

	/* Regular buffer - go direct */

	char *target = mem_get_region( buffer->render_addr );

	glDrawPixels( buffer->width, buffer->height, 

		      format, type, target );

    }

}