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/*
* Mesa 3-D graphics library
* Version: 6.5
*
* Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef S_SPAN_H
#define S_SPAN_H
#include "mtypes.h"
#include "swrast.h"
/**
* \defgroup SpanFlags
* Bitflags used for interpMask and arrayMask fields below to indicate
* which interpolant values and fragment arrays are in use, respectively.
*
* XXX We should replace these flags with the FRAG_BIT_ values someday...
*/
/*@{*/
#define SPAN_RGBA 0x001
#define SPAN_SPEC 0x002
#define SPAN_INDEX 0x004
#define SPAN_Z 0x008
#define SPAN_W 0x010
#define SPAN_FOG 0x020
#define SPAN_TEXTURE 0x040
#define SPAN_INT_TEXTURE 0x080
#define SPAN_LAMBDA 0x100
#define SPAN_COVERAGE 0x200
#define SPAN_FLAT 0x400 /**< flat shading? */
#define SPAN_XY 0x800
#define SPAN_MASK 0x1000
#define SPAN_VARYING 0x2000
/*@}*/
#if 0
/* alternate arrangement for code below */
struct arrays2 {
union {
GLubyte sz1[MAX_WIDTH][4]; /* primary color */
GLushort sz2[MAX_WIDTH][4];
} rgba;
union {
GLubyte sz1[MAX_WIDTH][4]; /* specular color and temp storage */
GLushort sz2[MAX_WIDTH][4];
} spec;
};
#endif
/**
* \sw_span_arrays
* \brief Arrays of fragment values.
*
* These will either be computed from the span x/xStep values or
* filled in by glDraw/CopyPixels, etc.
* These arrays are separated out of sw_span to conserve memory.
*/
typedef struct sw_span_arrays
{
/** Per-fragment attributes (indexed by FRAG_ATTRIB_* tokens) */
/* XXX someday look at transposing first two indexes for better memory
* access pattern.
*/
GLfloat attribs[FRAG_ATTRIB_MAX][MAX_WIDTH][4];
/** This mask indicates which fragments are alive or culled */
GLubyte mask[MAX_WIDTH];
GLenum ChanType; /**< Color channel type, GL_UNSIGNED_BYTE, GL_FLOAT */
union {
struct {
GLubyte rgba[MAX_WIDTH][4]; /**< primary color */
GLubyte spec[MAX_WIDTH][4]; /**< specular color and temp storage */
} sz1;
struct {
GLushort rgba[MAX_WIDTH][4];
GLushort spec[MAX_WIDTH][4];
} sz2;
} color;
/** XXX these are temporary fields, pointing into above color arrays */
GLchan (*rgba)[4];
GLchan (*spec)[4];
GLint x[MAX_WIDTH]; /**< fragment X coords */
GLint y[MAX_WIDTH]; /**< fragment Y coords */
GLuint z[MAX_WIDTH]; /**< fragment Z coords */
GLuint index[MAX_WIDTH]; /**< Color indexes */
GLfloat lambda[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH]; /**< Texture LOD */
GLfloat coverage[MAX_WIDTH]; /**< Fragment coverage for AA/smoothing */
} SWspanarrays;
/**
* The SWspan structure describes the colors, Z, fogcoord, texcoords,
* etc for either a horizontal run or an array of independent pixels.
* We can either specify a base/step to indicate interpolated values, or
* fill in explicit arrays of values. The interpMask and arrayMask bitfields
* indicate which attributes are active interpolants or arrays, respectively.
*
* It would be interesting to experiment with multiprocessor rasterization
* with this structure. The triangle rasterizer could simply emit a
* stream of these structures which would be consumed by one or more
* span-processing threads which could run in parallel.
*/
typedef struct sw_span
{
/** Coord of first fragment in horizontal span/run */
GLint x, y;
/** Number of fragments in the span */
GLuint end;
/** This flag indicates that mask[] array is effectively filled with ones */
GLboolean writeAll;
/** either GL_POLYGON, GL_LINE, GL_POLYGON, GL_BITMAP */
GLenum primitive;
/** 0 = front-facing span, 1 = back-facing span (for two-sided stencil) */
GLuint facing;
/**
* This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
* which of the attrStart/StepX/StepY variables are relevant.
*/
GLbitfield interpMask;
/** Fragment attribute interpolants */
GLfloat attrStart[FRAG_ATTRIB_MAX][4]; /**< initial value */
GLfloat attrStepX[FRAG_ATTRIB_MAX][4]; /**< dvalue/dx */
GLfloat attrStepY[FRAG_ATTRIB_MAX][4]; /**< dvalue/dy */
/* XXX the rest of these will go away eventually... */
/* For horizontal spans, step is the partial derivative wrt X.
* For lines, step is the delta from one fragment to the next.
*/
#if CHAN_TYPE == GL_FLOAT
GLfloat red, redStep;
GLfloat green, greenStep;
GLfloat blue, blueStep;
GLfloat alpha, alphaStep;
GLfloat specRed, specRedStep;
GLfloat specGreen, specGreenStep;
GLfloat specBlue, specBlueStep;
#else /* CHAN_TYPE == GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT */
GLfixed red, redStep;
GLfixed green, greenStep;
GLfixed blue, blueStep;
GLfixed alpha, alphaStep;
GLfixed specRed, specRedStep;
GLfixed specGreen, specGreenStep;
GLfixed specBlue, specBlueStep;
#endif
GLfixed index, indexStep;
GLfixed z, zStep; /* XXX z should probably be GLuint */
GLfixed intTex[2], intTexStep[2]; /* s, t only */
/**
* This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
* which of the fragment arrays in the span_arrays struct are relevant.
*/
GLbitfield arrayMask;
/**
* We store the arrays of fragment values in a separate struct so
* that we can allocate sw_span structs on the stack without using
* a lot of memory. The span_arrays struct is about 1.4MB while the
* sw_span struct is only about 512 bytes.
*/
SWspanarrays *array;
} SWspan;
#define INIT_SPAN(S, PRIMITIVE, END, INTERP_MASK, ARRAY_MASK) \
do { \
(S).primitive = (PRIMITIVE); \
(S).interpMask = (INTERP_MASK); \
(S).arrayMask = (ARRAY_MASK); \
(S).end = (END); \
(S).facing = 0; \
(S).array = SWRAST_CONTEXT(ctx)->SpanArrays; \
} while (0)
extern void
_swrast_span_default_z( GLcontext *ctx, SWspan *span );
extern void
_swrast_span_interpolate_z( const GLcontext *ctx, SWspan *span );
extern void
_swrast_span_default_fog( GLcontext *ctx, SWspan *span );
extern void
_swrast_span_default_color( GLcontext *ctx, SWspan *span );
extern void
_swrast_span_default_secondary_color(GLcontext *ctx, SWspan *span);
extern void
_swrast_span_default_texcoords( GLcontext *ctx, SWspan *span );
extern GLfloat
_swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
GLfloat s, GLfloat t, GLfloat q, GLfloat invQ);
extern void
_swrast_write_index_span( GLcontext *ctx, SWspan *span);
extern void
_swrast_write_rgba_span( GLcontext *ctx, SWspan *span);
extern void
_swrast_read_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
GLuint n, GLint x, GLint y, GLenum type, GLvoid *rgba);
extern void
_swrast_read_index_span( GLcontext *ctx, struct gl_renderbuffer *rb,
GLuint n, GLint x, GLint y, GLuint indx[] );
extern void
_swrast_get_values(GLcontext *ctx, struct gl_renderbuffer *rb,
GLuint count, const GLint x[], const GLint y[],
void *values, GLuint valueSize);
extern void
_swrast_put_row(GLcontext *ctx, struct gl_renderbuffer *rb,
GLuint count, GLint x, GLint y,
const GLvoid *values, GLuint valueSize);
extern void
_swrast_get_row(GLcontext *ctx, struct gl_renderbuffer *rb,
GLuint count, GLint x, GLint y,
GLvoid *values, GLuint valueSize);
extern void *
_swrast_get_dest_rgba(GLcontext *ctx, struct gl_renderbuffer *rb,
SWspan *span);
#endif
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