/* * Mesa 3-D graphics library * Version: 6.5.2 * * Copyright (C) 1999-2006 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. */ /** * \file swrast/s_context.h * \brief Software rasterization context and private types. * \author Keith Whitwell <keith@tungstengraphics.com> */ /** * \mainpage swrast module * * This module, software rasterization, contains the software fallback * routines for drawing points, lines, triangles, bitmaps and images. * All rendering boils down to writing spans (arrays) of pixels with * particular colors. The span-writing routines must be implemented * by the device driver. */ #ifndef S_CONTEXT_H #define S_CONTEXT_H #include "mtypes.h" #include "swrast.h" /** * \defgroup SpanFlags SPAN_XXX-flags * Bitmasks to indicate which sw_span_arrays need to be computed * (sw_span::interpMask) or have already been filled in (sw_span::arrayMask) */ /*@{*/ #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]; GLfloat sz4[MAX_WIDTH][4]; } rgba; union { GLubyte sz1[MAX_WIDTH][4]; /* specular color and temp storage */ GLushort sz2[MAX_WIDTH][4]; GLfloat sz4[MAX_WIDTH][4]; } spec; }; #endif /** * \sw_span_arrays * \brief Arrays of fragment values. * * These will either be computed from the x/xStep values above or * filled in by glDraw/CopyPixels, etc. * These arrays are separated out of sw_span to conserve memory. */ typedef struct sw_span_arrays { 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; struct { GLfloat rgba[MAX_WIDTH][4]; GLfloat spec[MAX_WIDTH][4]; } sz4; } color; /** XXX these are temporary fields, pointing into above color arrays */ GLchan (*rgba)[4]; GLchan (*spec)[4]; GLuint index[MAX_WIDTH]; GLint x[MAX_WIDTH]; /**< X/Y used for point/line rendering only */ GLint y[MAX_WIDTH]; /**< X/Y used for point/line rendering only */ GLuint z[MAX_WIDTH]; GLfloat fog[MAX_WIDTH]; GLfloat texcoords[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH][4]; GLfloat lambda[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH]; GLfloat coverage[MAX_WIDTH]; GLfloat varying[MAX_WIDTH][MAX_VARYING_VECTORS][VARYINGS_PER_VECTOR]; /** This mask indicates which fragments are alive or culled */ GLubyte mask[MAX_WIDTH]; } SWspanarrays; /** * \SWspan * \brief Contains data for either a horizontal line or a set of * pixels that are passed through a pipeline of functions before being * drawn. * * The sw_span 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 arrays of values. The interpMask and arrayMask bitfields * indicate which are active. * * With this structure it's easy to hand-off span rasterization to * subroutines instead of doing it all inline in the triangle functions * like we used to do. * It also cleans up the local variable namespace a great deal. * * 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 { GLint x, y; /** Only need to process pixels between start <= i < end */ /** At this time, start is always zero. */ GLuint start, 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 x/xStep variables are relevant. */ GLbitfield interpMask; /* 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 */ GLfloat fog, fogStep; GLfloat tex[MAX_TEXTURE_COORD_UNITS][4]; /* s, t, r, q */ GLfloat texStepX[MAX_TEXTURE_COORD_UNITS][4]; GLfloat texStepY[MAX_TEXTURE_COORD_UNITS][4]; GLfixed intTex[2], intTexStep[2]; /* s, t only */ GLfloat var[MAX_VARYING_VECTORS][VARYINGS_PER_VECTOR]; GLfloat varStepX[MAX_VARYING_VECTORS][VARYINGS_PER_VECTOR]; GLfloat varStepY[MAX_VARYING_VECTORS][VARYINGS_PER_VECTOR]; /* partial derivatives wrt X and Y. */ GLfloat dzdx, dzdy; GLfloat w, dwdx, dwdy; GLfloat drdx, drdy; GLfloat dgdx, dgdy; GLfloat dbdx, dbdy; GLfloat dadx, dady; GLfloat dsrdx, dsrdy; GLfloat dsgdx, dsgdy; GLfloat dsbdx, dsbdy; GLfloat dfogdx, dfogdy; /** * 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 400KB 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).start = 0; \ (S).end = (END); \ (S).facing = 0; \ (S).array = SWRAST_CONTEXT(ctx)->SpanArrays; \ } while (0) typedef void (*texture_sample_func)(GLcontext *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLchan rgba[][4]); typedef void (_ASMAPIP blend_func)( GLcontext *ctx, GLuint n, const GLubyte mask[], GLvoid *src, const GLvoid *dst, GLenum chanType); typedef void (*swrast_point_func)( GLcontext *ctx, const SWvertex *); typedef void (*swrast_line_func)( GLcontext *ctx, const SWvertex *, const SWvertex *); typedef void (*swrast_tri_func)( GLcontext *ctx, const SWvertex *, const SWvertex *, const SWvertex *); typedef void (*validate_texture_image_func)(GLcontext *ctx, struct gl_texture_object *texObj, GLuint face, GLuint level); /** \defgroup Bitmasks * Bitmasks to indicate which rasterization options are enabled * (RasterMask) */ /*@{*/ #define ALPHATEST_BIT 0x001 /**< Alpha-test pixels */ #define BLEND_BIT 0x002 /**< Blend pixels */ #define DEPTH_BIT 0x004 /**< Depth-test pixels */ #define FOG_BIT 0x008 /**< Fog pixels */ #define LOGIC_OP_BIT 0x010 /**< Apply logic op in software */ #define CLIP_BIT 0x020 /**< Scissor or window clip pixels */ #define STENCIL_BIT 0x040 /**< Stencil pixels */ #define MASKING_BIT 0x080 /**< Do glColorMask or glIndexMask */ #define MULTI_DRAW_BIT 0x400 /**< Write to more than one color- */ /**< buffer or no buffers. */ #define OCCLUSION_BIT 0x800 /**< GL_HP_occlusion_test enabled */ #define TEXTURE_BIT 0x1000 /**< Texturing really enabled */ #define FRAGPROG_BIT 0x2000 /**< Fragment program enabled */ #define ATIFRAGSHADER_BIT 0x4000 /**< ATI Fragment shader enabled */ #define CLAMPING_BIT 0x8000 /**< Clamp colors to [0,1] */ /*@}*/ #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS| \ _NEW_SCISSOR| \ _NEW_COLOR| \ _NEW_DEPTH| \ _NEW_FOG| \ _NEW_PROGRAM| \ _NEW_STENCIL| \ _NEW_TEXTURE| \ _NEW_VIEWPORT| \ _NEW_DEPTH) /** * \struct SWcontext * \brief Per-context state that's private to the software rasterizer module. */ typedef struct { /** Driver interface: */ struct swrast_device_driver Driver; /** Configuration mechanisms to make software rasterizer match * characteristics of the hardware rasterizer (if present): */ GLboolean AllowVertexFog; GLboolean AllowPixelFog; /** Derived values, invalidated on statechanges, updated from * _swrast_validate_derived(): */ GLbitfield _RasterMask; GLfloat _BackfaceSign; GLboolean _PreferPixelFog; /* Compute fog blend factor per fragment? */ GLboolean _AnyTextureCombine; GLboolean _FogEnabled; GLenum _FogMode; /* either GL_FOG_MODE or fragment program's fog mode */ /* Accum buffer temporaries. */ GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */ GLfloat _IntegerAccumScaler; /**< Implicit scale factor */ /* Working values: */ GLuint StippleCounter; /**< Line stipple counter */ GLbitfield NewState; GLuint StateChanges; GLenum Primitive; /* current primitive being drawn (ala glBegin) */ void (*InvalidateState)( GLcontext *ctx, GLbitfield new_state ); /** * When the NewState mask intersects these masks, we invalidate the * Point/Line/Triangle function pointers below. */ /*@{*/ GLbitfield InvalidatePointMask; GLbitfield InvalidateLineMask; GLbitfield InvalidateTriangleMask; /*@}*/ /** * Device drivers plug in functions for these callbacks. * Will be called when the GL state change mask intersects the above masks. */ /*@{*/ void (*choose_point)( GLcontext * ); void (*choose_line)( GLcontext * ); void (*choose_triangle)( GLcontext * ); /*@}*/ /** * Current point, line and triangle drawing functions. */ /*@{*/ swrast_point_func Point; swrast_line_func Line; swrast_tri_func Triangle; /*@}*/ /** * Placeholders for when separate specular (or secondary color) is * enabled but texturing is not. */ /*@{*/ swrast_point_func SpecPoint; swrast_line_func SpecLine; swrast_tri_func SpecTriangle; /*@}*/ /** * Typically, we'll allocate a sw_span structure as a local variable * and set its 'array' pointer to point to this object. The reason is * this object is big and causes problems when allocated on the stack * on some systems. */ SWspanarrays *SpanArrays; /** * Used to buffer N GL_POINTS, instead of rendering one by one. */ SWspan PointSpan; /** Internal hooks, kept up to date by the same mechanism as above. */ blend_func BlendFunc; texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS]; /** Buffer for saving the sampled texture colors. * Needed for GL_ARB_texture_env_crossbar implementation. */ GLchan *TexelBuffer; validate_texture_image_func ValidateTextureImage; } SWcontext; extern void _swrast_validate_derived( GLcontext *ctx ); #define SWRAST_CONTEXT(ctx) ((SWcontext *)ctx->swrast_context) #define RENDER_START(SWctx, GLctx) \ do { \ if ((SWctx)->Driver.SpanRenderStart) { \ (*(SWctx)->Driver.SpanRenderStart)(GLctx); \ } \ } while (0) #define RENDER_FINISH(SWctx, GLctx) \ do { \ if ((SWctx)->Driver.SpanRenderFinish) { \ (*(SWctx)->Driver.SpanRenderFinish)(GLctx); \ } \ } while (0) /** * Size of an RGBA pixel, in bytes, for given datatype. */ #define RGBA_PIXEL_SIZE(TYPE) \ ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) : \ ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort) \ : 4 * sizeof(GLfloat))) /* * XXX these macros are just bandages for now in order to make * CHAN_BITS==32 compile cleanly. * These should probably go elsewhere at some point. */ #if CHAN_TYPE == GL_FLOAT #define ChanToFixed(X) (X) #define FixedToChan(X) (X) #else #define ChanToFixed(X) IntToFixed(X) #define FixedToChan(X) FixedToInt(X) #endif #endif