/**

  * $Id: rendcore.c,v 1.2 2006-08-02 06:24:08 nkeynes Exp $

  *

  * PVR2 renderer core.

  *

  * 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"

 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 POLY1_DEPTH_MODE(poly1) ( pvr2_poly_depthmode[(poly1)>>29] )

 #define POLY1_DEPTH_ENABLE(poly1) (((poly1)&0x04000000) == 0 )

 #define POLY1_CULL_MODE(poly1) (((poly1)>>27)&0x03)

 #define POLY1_TEXTURED(poly1) (((poly1)&0x02000000))

 #define POLY1_SPECULAR(poly1) (((poly1)&0x01000000))

 #define POLY1_SHADE_MODEL(poly1) (((poly1)&0x00800000) ? GL_SMOOTH : GL_FLAT)

 #define POLY1_UV16(poly1)   (((poly1)&0x00400000))

 #define POLY1_SINGLE_TILE(poly1) (((poly1)&0x00200000))

 #define POLY2_SRC_BLEND(poly2) ( pvr2_poly_srcblend[(poly2) >> 29] )

 #define POLY2_DEST_BLEND(poly2) ( pvr2_poly_dstblend[((poly2)>>26)&0x07] )

 #define POLY2_SRC_BLEND_ENABLE(poly2) ((poly2)&0x02000000)

 #define POLY2_DEST_BLEND_ENABLE(poly2) ((poly2)&0x01000000)

 #define POLY2_COLOUR_CLAMP_ENABLE(poly2) ((poly2)&0x00200000)

 #define POLY2_ALPHA_ENABLE(poly2) ((poly2)&0x001000000)

 #define POLY2_TEX_ALPHA_ENABLE(poly2) (((poly2)&0x00080000) == 0 )

 #define POLY2_TEX_WIDTH(poly2) ( 1<< ((((poly2) >> 3) & 0x07 ) + 3) )

 #define POLY2_TEX_HEIGHT(poly2) ( 1<< (((poly2) & 0x07 ) + 3) )

 #define POLY2_TEX_BLEND(poly2) ( pvr2_poly_texblend[((poly2) >> 6)&0x03] )

 #define RENDER_ZONLY  0

 #define RENDER_NORMAL 1     /* Render non-modified polygons */

 #define RENDER_CHEAPMOD 2   /* Render cheap-modified polygons */

 #define RENDER_FULLMOD 3    /* Render the fully-modified version of the polygons */

 #define CULL_NONE 0

 #define CULL_SMALL 1

 #define CULL_CCW 2

 #define CULL_CW 3

 #define SEGMENT_END         0x80000000

 #define SEGMENT_SORT_TRANS  0x20000000

 #define SEGMENT_START       0x10000000

 #define SEGMENT_X(c)        (((c) >> 2) & 0x3F)

 #define SEGMENT_Y(c)        (((c) >> 8) & 0x3F)

 #define NO_POINTER          0x80000000

 extern char *video_base;

 struct tile_segment {

     uint32_t control;

     pvraddr_t opaque_ptr;

     pvraddr_t opaquemod_ptr;

     pvraddr_t trans_ptr;

     pvraddr_t transmod_ptr;

     pvraddr_t punchout_ptr;

 };

 /**

  * Convert a half-float (16-bit) FP number to a regular 32-bit float.

  * Source is 1-bit sign, 5-bit exponent, 10-bit mantissa.

  * TODO: Check the correctness of this.

  */

 float halftofloat( uint16_t half )

 {

     union {

         float f;

         uint32_t i;

     } temp;

     int e = ((half & 0x7C00) >> 10) - 15 + 127;

     temp.i = ((half & 0x8000) << 16) | (e << 23) |

              ((half & 0x03FF) << 13);

     return temp.f;

 }

 /**

  * Setup the GL context for the supplied polygon context.

  * @param context pointer to 3 or 5 words of polygon context

  * @param modified boolean flag indicating that the modified

  *  version should be used, rather than the normal version.

  */

 void render_set_context( uint32_t *context, int render_mode )

 {

     uint32_t poly1 = context[0], poly2, texture;

     if( render_mode == RENDER_FULLMOD ) {

 	poly2 = context[3];

 	texture = context[4];

     } else {

 	poly2 = context[1];

 	texture = context[2];

     }

     if( POLY1_DEPTH_ENABLE(poly1) ) {

 	glEnable( GL_DEPTH_TEST );

 	glDepthFunc( POLY1_DEPTH_MODE(poly1) );

     } else {

 	glDisable( GL_DEPTH_TEST );

     }

     switch( POLY1_CULL_MODE(poly1) ) {

     case CULL_NONE:

     case CULL_SMALL:

 	glDisable( GL_CULL_FACE );

 	break;

     case CULL_CCW:

 	glEnable( GL_CULL_FACE );

 	glFrontFace( GL_CW );

 	break;

     case CULL_CW:

 	glEnable( GL_CULL_FACE );

 	glFrontFace( GL_CCW );

 	break;

     }

     if( POLY1_TEXTURED(poly1) ) {

 	int width = POLY2_TEX_WIDTH(poly2);

 	int height = POLY2_TEX_HEIGHT(poly2);

 	glEnable(GL_TEXTURE_2D);

 	texcache_get_texture( (texture&0x001FFFFF)<<3, width, height, texture );

 	glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, POLY2_TEX_BLEND(poly2) );

     } else {

 	glDisable( GL_TEXTURE_2D );

     }

     glShadeModel( POLY1_SHADE_MODEL(poly1) );

     glBlendFunc( POLY2_SRC_BLEND(poly2), POLY2_DEST_BLEND(poly2) );

     if( POLY2_TEX_ALPHA_ENABLE(poly2) ) {

 	glEnable(GL_BLEND);

     } else {

 	glDisable(GL_BLEND);

     }

 }

 void render_vertexes( uint32_t poly1, uint32_t *vertexes, int num_vertexes, int vertex_size,

 		      int render_mode ) 

 {

     int i, m=0;

     if( render_mode == RENDER_FULLMOD ) {

 	m = (vertex_size - 3)/2;

     }

     glBegin( GL_TRIANGLE_STRIP );

     for( i=0; i<num_vertexes; i++ ) {

 	float *vertexf = (float *)vertexes;

 	uint32_t argb;

 	if( POLY1_TEXTURED(poly1) ) {

 	    if( POLY1_UV16(poly1) ) {

 		glTexCoord2f( halftofloat(vertexes[m+3]>>16),

 			      halftofloat(vertexes[m+3]) );

 		argb = vertexes[m+4];

 	    } else {

 		glTexCoord2f( vertexf[m+3], vertexf[m+4] );

 		argb = vertexes[m+5];

 	    }

 	} else {

 	    argb = vertexes[m+3];

 	}

 	glColor4ub( (GLubyte)(argb >> 16), (GLubyte)(argb >> 8), 

 		    (GLubyte)argb, (GLubyte)(argb >> 24) );

 	glVertex3f( vertexf[0], vertexf[1], vertexf[2] );

 	vertexes += vertex_size;

     }

     glEnd();

 }

 /**

  * Render a simple (not auto-sorted) tile

  */

 void render_tile( pvraddr_t tile_entry, int render_mode, gboolean cheap_modifier_mode ) {

     uint32_t *tile_list = (uint32_t *)(video_base+tile_entry);

     do {

 	uint32_t entry = *tile_list++;

 	if( entry >> 28 == 0x0F ) {

 	    break;

 	} else if( entry >> 28 == 0x0E ) {

 	    tile_list = (uint32_t *)(video_base + (entry&0x007FFFFF));

 	} else {

 	    uint32_t *polygon = (uint32_t *)(video_base + ((entry & 0x001FFFFF) << 2));

 	    int is_modified = entry & 0x01000000;

 	    int vertex_length = (entry >> 21) & 0x07;

 	    int context_length = 3;

 	    if( is_modified && !cheap_modifier_mode ) {

 		context_length = 5;

 		vertex_length *= 2 ;

 	    }

 	    vertex_length += 3;

 	    if( (entry & 0xE0000000) == 0x80000000 ) {

 		/* Triangle(s) */

 		int strip_count = ((entry >> 25) & 0x0F)+1;

 		int polygon_length = 3 * vertex_length + context_length;

 		int i;

 		for( i=0; i<strip_count; i++ ) {

 		    render_set_context( polygon, render_mode );

 		    render_vertexes( *polygon, polygon+context_length, 3, vertex_length,

 				     render_mode );

 		    polygon += polygon_length;

 		}

 	    } else if( (entry & 0xE0000000) == 0xA0000000 ) {

 		/* Sprite(s) */

 		int strip_count = (entry >> 25) & 0x0F;

 		int polygon_length = 4 * vertex_length + context_length;

 		int i;

 		for( i=0; i<strip_count; i++ ) {

 		    render_set_context( polygon, render_mode );

 		    render_vertexes( *polygon, polygon+context_length, 4, vertex_length,

 				     render_mode );

 		    polygon += polygon_length;

 		}

 	    } else {

 		/* Polygon */

 		int i, first=-1, last = -1;

 		for( i=0; i<6; i++ ) {

 		    if( entry & (0x40000000>>i) ) {

 			if( first == -1 ) first = i;

 			last = i;

 		    }

 		}

 		if( first != -1 ) {

 		    first = 0;

 		    render_set_context(polygon, render_mode);

 		    render_vertexes( *polygon, polygon+context_length + (first*vertex_length),

 				     (last-first+3), vertex_length, render_mode );

 		}

 	    }

 	}

     } while( 1 );

 }

 void render_autosort_tile( pvraddr_t tile_entry, int render_mode, gboolean cheap_modifier_mode ) {

     //WARN( "Autosort not implemented yet" );

     render_tile( tile_entry, render_mode, cheap_modifier_mode );

 }

 void pvr2_render_tilebuffer( int width, int height, int clipx1, int clipy1, 

 			int clipx2, int clipy2 ) {

     pvraddr_t segmentbase = MMIO_READ( PVR2, RENDER_TILEBASE );

     int tile_sort;

     gboolean cheap_shadow;

     int obj_config = MMIO_READ( PVR2, RENDER_OBJCFG );

     int isp_config = MMIO_READ( PVR2, RENDER_ISPCFG );

     int shadow_cfg = MMIO_READ( PVR2, RENDER_SHADOW );

     if( obj_config & 0x00200000 ) {

 	if( isp_config & 1 ) {

 	    tile_sort = 0;

 	} else {

 	    tile_sort = 2;

 	}

     } else {

 	tile_sort = 1;

     }

     cheap_shadow = shadow_cfg & 0x100 ? TRUE : FALSE;

     struct tile_segment *segment = (struct tile_segment *)(video_base + segmentbase);

     glEnable( GL_SCISSOR_TEST );

     while( (segment->control & SEGMENT_END) == 0 ) {

 	int tilex = SEGMENT_X(segment->control);

 	int tiley = SEGMENT_Y(segment->control);

 	int x1 = tilex << 5;

 	int y1 = tiley << 5;

 	if( x1 + 32 <= clipx1 ||

 	    y1 + 32 <= clipy1 ||

 	    x1 >= clipx2 ||

 	    y1 >= clipy2 ) {

 	    /* Tile completely clipped, skip */

 	    segment++;

 	    continue;

 	}

 	/* Set a scissor on the visible part of the tile */

 	int w = MIN(x1+32, clipx2) - x1;

 	int h = MIN(y1+32, clipy2) - y1;

 	x1 = MAX(x1,clipx1);

 	y1 = MAX(y1,clipy1);

 	glScissor( x1, height-y1-h, w, h );

 	if( (segment->opaque_ptr & NO_POINTER) == 0 ) {

 	    if( (segment->opaquemod_ptr & NO_POINTER) == 0 ) {

 		/* TODO */

 	    }

 	    render_tile( segment->opaque_ptr, RENDER_NORMAL, cheap_shadow );

 	}

 	if( (segment->trans_ptr & NO_POINTER) == 0 ) {

 	    if( (segment->transmod_ptr & NO_POINTER) == 0 ) {

 		/* TODO */

 	    } 

 	    if( tile_sort == 2 || (tile_sort == 1 && (segment->control & SEGMENT_SORT_TRANS)) ) {

 		render_autosort_tile( segment->trans_ptr, RENDER_NORMAL, cheap_shadow );

 	    } else {

 		render_tile( segment->trans_ptr, RENDER_NORMAL, cheap_shadow );

 	    }

 	}

 	if( (segment->punchout_ptr & NO_POINTER) == 0 ) {

 	    render_tile( segment->punchout_ptr, RENDER_NORMAL, cheap_shadow );

 	}

 	segment++;

     }

     glDisable( GL_SCISSOR_TEST );

 }