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Diffstat (limited to 'src/mesa/swrast/s_span.h')
| -rw-r--r-- | src/mesa/swrast/s_span.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/src/mesa/swrast/s_span.h b/src/mesa/swrast/s_span.h index c441106aba..8a9b9eb21c 100644 --- a/src/mesa/swrast/s_span.h +++ b/src/mesa/swrast/s_span.h @@ -31,6 +31,185 @@ #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 ); |