/* * Mesa 3-D graphics library * Version: 7.5 * * Copyright (C) 1999-2008 Brian Paul All Rights Reserved. * Copyright (C) 2009 VMware, Inc. 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 "swrast.h" /** * \defgroup SpanFlags * Special bitflags to describe span data. * * In general, the point/line/triangle functions interpolate/emit the * attributes specified by swrast->_ActiveAttribs (i.e. FRAT_BIT_* values). * Some things don't fit into that, though, so we have these flags. */ /*@{*/ #define SPAN_RGBA 0x01 /**< interpMask and arrayMask */ #define SPAN_INDEX 0x02 /**< interpMask and arrayMask */ #define SPAN_Z 0x04 /**< interpMask and arrayMask */ #define SPAN_FLAT 0x08 /**< interpMask: flat shading? */ #define SPAN_XY 0x10 /**< array.x[], y[] valid? */ #define SPAN_MASK 0x20 /**< was array.mask[] filled in by caller? */ #define SPAN_LAMBDA 0x40 /**< array.lambda[] valid? */ #define SPAN_COVERAGE 0x80 /**< array.coverage[] valid? */ /*@}*/ /** * \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 */ /** Attribute arrays that don't fit into attribs[] array above */ /*@{*/ GLubyte rgba8[MAX_WIDTH][4]; GLushort rgba16[MAX_WIDTH][4]; GLchan (*rgba)[4]; /** either == rgba8 or rgba16 */ 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; /** for clipping left edge of spans */ GLuint leftClip; /** 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. */ GLfixed red, redStep; GLfixed green, greenStep; GLfixed blue, blueStep; GLfixed alpha, alphaStep; GLfixed index, indexStep; GLfixed z, zStep; /**< XXX z should probably be GLuint */ GLfixed intTex[2], intTexStep[2]; /**< (s,t) for unit[0] only */ /** * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates * which of the fragment arrays in the span_arrays struct are relevant. */ GLbitfield arrayMask; GLbitfield arrayAttribs; /** * 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) \ do { \ (S).primitive = (PRIMITIVE); \ (S).interpMask = 0x0; \ (S).arrayMask = 0x0; \ (S).arrayAttribs = 0x0; \ (S).end = 0; \ (S).leftClip = 0; \ (S).facing = 0; \ (S).array = SWRAST_CONTEXT(ctx)->SpanArrays; \ } while (0) extern void _swrast_span_default_attribs(GLcontext *ctx, SWspan *span); extern void _swrast_span_interpolate_z( const 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_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_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