512134db0f83bd1b0a07ec5f845b35a2eaae10e4
2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
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8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
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14 * The above copyright notice and this permission notice shall be included
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17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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36 * Special bitflags to describe span data.
38 * In general, the point/line/triangle functions interpolate/emit the
39 * attributes specified by swrast->_ActiveAttribs (i.e. FRAT_BIT_* values).
40 * Some things don't fit into that, though, so we have these flags.
43 #define SPAN_RGBA 0x01 /**< interpMask and arrayMask */
44 #define SPAN_INDEX 0x02 /**< interpMask and arrayMask */
45 #define SPAN_Z 0x04 /**< interpMask and arrayMask */
46 #define SPAN_FLAT 0x08 /**< interpMask: flat shading? */
47 #define SPAN_XY 0x10 /**< array.x[], y[] valid? */
48 #define SPAN_MASK 0x20 /**< was array.mask[] filled in by caller? */
49 #define SPAN_LAMBDA 0x40 /**< array.lambda[] valid? */
50 #define SPAN_COVERAGE 0x80 /**< array.coverage[] valid? */
56 * \brief Arrays of fragment values.
58 * These will either be computed from the span x/xStep values or
59 * filled in by glDraw/CopyPixels, etc.
60 * These arrays are separated out of sw_span to conserve memory.
62 typedef struct sw_span_arrays
64 /** Per-fragment attributes (indexed by FRAG_ATTRIB_* tokens) */
65 /* XXX someday look at transposing first two indexes for better memory
68 GLfloat attribs
[FRAG_ATTRIB_MAX
][MAX_WIDTH
][4];
70 /** This mask indicates which fragments are alive or culled */
71 GLubyte mask
[MAX_WIDTH
];
73 GLenum ChanType
; /**< Color channel type, GL_UNSIGNED_BYTE, GL_FLOAT */
75 /** Attribute arrays that don't fit into attribs[] array above */
77 GLubyte rgba8
[MAX_WIDTH
][4];
78 GLushort rgba16
[MAX_WIDTH
][4];
79 GLchan (*rgba
)[4]; /** either == rgba8 or rgba16 */
80 GLint x
[MAX_WIDTH
]; /**< fragment X coords */
81 GLint y
[MAX_WIDTH
]; /**< fragment Y coords */
82 GLuint z
[MAX_WIDTH
]; /**< fragment Z coords */
83 GLuint index
[MAX_WIDTH
]; /**< Color indexes */
84 GLfloat lambda
[MAX_TEXTURE_COORD_UNITS
][MAX_WIDTH
]; /**< Texture LOD */
85 GLfloat coverage
[MAX_WIDTH
]; /**< Fragment coverage for AA/smoothing */
91 * The SWspan structure describes the colors, Z, fogcoord, texcoords,
92 * etc for either a horizontal run or an array of independent pixels.
93 * We can either specify a base/step to indicate interpolated values, or
94 * fill in explicit arrays of values. The interpMask and arrayMask bitfields
95 * indicate which attributes are active interpolants or arrays, respectively.
97 * It would be interesting to experiment with multiprocessor rasterization
98 * with this structure. The triangle rasterizer could simply emit a
99 * stream of these structures which would be consumed by one or more
100 * span-processing threads which could run in parallel.
102 typedef struct sw_span
104 /** Coord of first fragment in horizontal span/run */
107 /** Number of fragments in the span */
110 /** This flag indicates that mask[] array is effectively filled with ones */
113 /** either GL_POLYGON, GL_LINE, GL_POLYGON, GL_BITMAP */
116 /** 0 = front-facing span, 1 = back-facing span (for two-sided stencil) */
120 * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
121 * which of the attrStart/StepX/StepY variables are relevant.
123 GLbitfield interpMask
;
125 /** Fragment attribute interpolants */
126 GLfloat attrStart
[FRAG_ATTRIB_MAX
][4]; /**< initial value */
127 GLfloat attrStepX
[FRAG_ATTRIB_MAX
][4]; /**< dvalue/dx */
128 GLfloat attrStepY
[FRAG_ATTRIB_MAX
][4]; /**< dvalue/dy */
130 /* XXX the rest of these will go away eventually... */
132 /* For horizontal spans, step is the partial derivative wrt X.
133 * For lines, step is the delta from one fragment to the next.
135 GLfixed red
, redStep
;
136 GLfixed green
, greenStep
;
137 GLfixed blue
, blueStep
;
138 GLfixed alpha
, alphaStep
;
139 GLfixed index
, indexStep
;
140 GLfixed z
, zStep
; /**< XXX z should probably be GLuint */
141 GLfixed intTex
[2], intTexStep
[2]; /**< (s,t) for unit[0] only */
144 * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
145 * which of the fragment arrays in the span_arrays struct are relevant.
147 GLbitfield arrayMask
;
149 GLbitfield arrayAttribs
;
152 * We store the arrays of fragment values in a separate struct so
153 * that we can allocate sw_span structs on the stack without using
154 * a lot of memory. The span_arrays struct is about 1.4MB while the
155 * sw_span struct is only about 512 bytes.
162 #define INIT_SPAN(S, PRIMITIVE) \
164 (S).primitive = (PRIMITIVE); \
165 (S).interpMask = 0x0; \
166 (S).arrayMask = 0x0; \
167 (S).arrayAttribs = 0x0; \
170 (S).array = SWRAST_CONTEXT(ctx)->SpanArrays; \
176 _swrast_span_default_attribs(GLcontext
*ctx
, SWspan
*span
);
179 _swrast_span_interpolate_z( const GLcontext
*ctx
, SWspan
*span
);
182 _swrast_compute_lambda(GLfloat dsdx
, GLfloat dsdy
, GLfloat dtdx
, GLfloat dtdy
,
183 GLfloat dqdx
, GLfloat dqdy
, GLfloat texW
, GLfloat texH
,
184 GLfloat s
, GLfloat t
, GLfloat q
, GLfloat invQ
);
187 _swrast_write_index_span( GLcontext
*ctx
, SWspan
*span
);
191 _swrast_write_rgba_span( GLcontext
*ctx
, SWspan
*span
);
195 _swrast_read_rgba_span(GLcontext
*ctx
, struct gl_renderbuffer
*rb
,
196 GLuint n
, GLint x
, GLint y
, GLenum type
, GLvoid
*rgba
);
199 _swrast_read_index_span( GLcontext
*ctx
, struct gl_renderbuffer
*rb
,
200 GLuint n
, GLint x
, GLint y
, GLuint indx
[] );
203 _swrast_get_values(GLcontext
*ctx
, struct gl_renderbuffer
*rb
,
204 GLuint count
, const GLint x
[], const GLint y
[],
205 void *values
, GLuint valueSize
);
208 _swrast_put_row(GLcontext
*ctx
, struct gl_renderbuffer
*rb
,
209 GLuint count
, GLint x
, GLint y
,
210 const GLvoid
*values
, GLuint valueSize
);
213 _swrast_get_row(GLcontext
*ctx
, struct gl_renderbuffer
*rb
,
214 GLuint count
, GLint x
, GLint y
,
215 GLvoid
*values
, GLuint valueSize
);
219 _swrast_get_dest_rgba(GLcontext
*ctx
, struct gl_renderbuffer
*rb
,