/* * Mesa 3-D graphics library * Version: 4.0 * * Copyright (C) 1999-2001 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. */ /* Authors: * David Bucciarelli * Brian Paul * Daryll Strauss * Keith Whitwell * Daniel Borca * Hiroshi Morii */ /* fxdd.c - 3Dfx VooDoo Mesa span and pixel functions */ #ifdef HAVE_CONFIG_H #include "conf.h" #endif #if defined(FX) #include "fxdrv.h" #include "fxglidew.h" #include "swrast/swrast.h" /************************************************************************/ /***** Span functions *****/ /************************************************************************/ #define DBG 0 #define LOCAL_VARS \ GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER; \ GLuint pitch = info.strideInBytes; \ GLuint height = fxMesa->height; \ char *buf = (char *)((char *)info.lfbPtr + 0 /* x, y offset */); \ GLuint p; \ (void) buf; (void) p; #define CLIPPIXEL( _x, _y ) ( _x >= minx && _x < maxx && \ _y >= miny && _y < maxy ) #define CLIPSPAN( _x, _y, _n, _x1, _n1, _i ) \ if ( _y < miny || _y >= maxy ) { \ _n1 = 0, _x1 = x; \ } else { \ _n1 = _n; \ _x1 = _x; \ if ( _x1 < minx ) _i += (minx-_x1), n1 -= (minx-_x1), _x1 = minx;\ if ( _x1 + _n1 >= maxx ) n1 -= (_x1 + n1 - maxx); \ } #define Y_FLIP(_y) (height - _y - 1) #define HW_WRITE_LOCK() \ fxMesaContext fxMesa = FX_CONTEXT(ctx); \ GrLfbInfo_t info; \ info.size = sizeof(GrLfbInfo_t); \ if ( grLfbLock( GR_LFB_WRITE_ONLY, \ currentFB, LFB_MODE, \ GR_ORIGIN_UPPER_LEFT, FXFALSE, &info ) ) { #define HW_WRITE_UNLOCK() \ grLfbUnlock( GR_LFB_WRITE_ONLY, currentFB ); \ } #define HW_READ_LOCK() \ fxMesaContext fxMesa = FX_CONTEXT(ctx); \ GrLfbInfo_t info; \ info.size = sizeof(GrLfbInfo_t); \ if ( grLfbLock( GR_LFB_READ_ONLY, currentFB, \ LFB_MODE, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info ) ) { #define HW_READ_UNLOCK() \ grLfbUnlock( GR_LFB_READ_ONLY, currentFB ); \ } #define HW_WRITE_CLIPLOOP() \ do { \ /* remember, we need to flip the scissor, too */ \ /* is it better to do it inside fxDDScissor? */ \ const int minx = fxMesa->clipMinX; \ const int maxy = Y_FLIP(fxMesa->clipMinY); \ const int maxx = fxMesa->clipMaxX; \ const int miny = Y_FLIP(fxMesa->clipMaxY); #define HW_READ_CLIPLOOP() \ do { \ /* remember, we need to flip the scissor, too */ \ /* is it better to do it inside fxDDScissor? */ \ const int minx = fxMesa->clipMinX; \ const int maxy = Y_FLIP(fxMesa->clipMinY); \ const int maxx = fxMesa->clipMaxX; \ const int miny = Y_FLIP(fxMesa->clipMaxY); #define HW_ENDCLIPLOOP() \ } while (0) /* 16 bit, ARGB1555 color spanline and pixel functions */ #undef LFB_MODE #define LFB_MODE GR_LFBWRITEMODE_1555 #undef BYTESPERPIXEL #define BYTESPERPIXEL 2 #undef INIT_MONO_PIXEL #define INIT_MONO_PIXEL(p, color) \ p = TDFXPACKCOLOR1555( color[RCOMP], color[GCOMP], color[BCOMP], color[ACOMP] ) #define WRITE_RGBA( _x, _y, r, g, b, a ) \ *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) = \ TDFXPACKCOLOR1555( r, g, b, a ) #define WRITE_PIXEL( _x, _y, p ) \ *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) = p #define READ_RGBA( rgba, _x, _y ) \ do { \ GLushort p = *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch); \ rgba[0] = FX_rgb_scale_5[(p >> 10) & 0x1F]; \ rgba[1] = FX_rgb_scale_5[(p >> 5) & 0x1F]; \ rgba[2] = FX_rgb_scale_5[ p & 0x1F]; \ rgba[3] = (p & 0x8000) ? 255 : 0; \ } while (0) #define TAG(x) tdfx##x##_ARGB1555 #include "../dri/common/spantmp.h" /* 16 bit, RGB565 color spanline and pixel functions */ /* [dBorca] Hack alert: * This is wrong. The alpha value is lost, even when we provide * HW alpha (565 w/o depth buffering). To really update alpha buffer, * we would need to do the 565 writings via 8888 colorformat and rely * on the Voodoo to perform color scaling. In which case our 565 span * would look nicer! But this violates FSAA rules... */ #undef LFB_MODE #define LFB_MODE GR_LFBWRITEMODE_565 #undef BYTESPERPIXEL #define BYTESPERPIXEL 2 #undef INIT_MONO_PIXEL #define INIT_MONO_PIXEL(p, color) \ p = TDFXPACKCOLOR565( color[RCOMP], color[GCOMP], color[BCOMP] ) #define WRITE_RGBA( _x, _y, r, g, b, a ) \ *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) = \ TDFXPACKCOLOR565( r, g, b ) #define WRITE_PIXEL( _x, _y, p ) \ *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) = p #define READ_RGBA( rgba, _x, _y ) \ do { \ GLushort p = *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch); \ rgba[0] = FX_rgb_scale_5[(p >> 11) & 0x1F]; \ rgba[1] = FX_rgb_scale_6[(p >> 5) & 0x3F]; \ rgba[2] = FX_rgb_scale_5[ p & 0x1F]; \ rgba[3] = 0xff; \ } while (0) #define TAG(x) tdfx##x##_RGB565 #include "../dri/common/spantmp.h" /* 32 bit, ARGB8888 color spanline and pixel functions */ #undef LFB_MODE #define LFB_MODE GR_LFBWRITEMODE_8888 #undef BYTESPERPIXEL #define BYTESPERPIXEL 4 #undef INIT_MONO_PIXEL #define INIT_MONO_PIXEL(p, color) \ p = TDFXPACKCOLOR8888( color[RCOMP], color[GCOMP], color[BCOMP], color[ACOMP] ) #define WRITE_RGBA( _x, _y, r, g, b, a ) \ *(GLuint *)(buf + _x*BYTESPERPIXEL + _y*pitch) = \ TDFXPACKCOLOR8888( r, g, b, a ) #define WRITE_PIXEL( _x, _y, p ) \ *(GLuint *)(buf + _x*BYTESPERPIXEL + _y*pitch) = p #define READ_RGBA( rgba, _x, _y ) \ do { \ GLuint p = *(GLuint *)(buf + _x*BYTESPERPIXEL + _y*pitch); \ rgba[0] = (p >> 16) & 0xff; \ rgba[1] = (p >> 8) & 0xff; \ rgba[2] = (p >> 0) & 0xff; \ rgba[3] = (p >> 24) & 0xff; \ } while (0) #define TAG(x) tdfx##x##_ARGB8888 #include "../dri/common/spantmp.h" /************************************************************************/ /***** Depth functions *****/ /************************************************************************/ #define DBG 0 #undef HW_WRITE_LOCK #undef HW_WRITE_UNLOCK #undef HW_READ_LOCK #undef HW_READ_UNLOCK #define HW_CLIPLOOP HW_WRITE_CLIPLOOP #define LOCAL_DEPTH_VARS \ GLuint pitch = info.strideInBytes; \ GLuint height = fxMesa->height; \ char *buf = (char *)((char *)info.lfbPtr + 0 /* x, y offset */); \ (void) buf; #define HW_WRITE_LOCK() \ fxMesaContext fxMesa = FX_CONTEXT(ctx); \ GrLfbInfo_t info; \ info.size = sizeof(GrLfbInfo_t); \ if ( grLfbLock( GR_LFB_WRITE_ONLY, \ GR_BUFFER_AUXBUFFER, LFB_MODE, \ GR_ORIGIN_UPPER_LEFT, FXFALSE, &info ) ) { #define HW_WRITE_UNLOCK() \ grLfbUnlock( GR_LFB_WRITE_ONLY, GR_BUFFER_AUXBUFFER); \ } #define HW_READ_LOCK() \ fxMesaContext fxMesa = FX_CONTEXT(ctx); \ GrLfbInfo_t info; \ info.size = sizeof(GrLfbInfo_t); \ if ( grLfbLock( GR_LFB_READ_ONLY, GR_BUFFER_AUXBUFFER, \ LFB_MODE, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info ) ) { #define HW_READ_UNLOCK() \ grLfbUnlock( GR_LFB_READ_ONLY, GR_BUFFER_AUXBUFFER); \ } /* 16 bit, depth spanline and pixel functions */ #undef LFB_MODE #define LFB_MODE GR_LFBWRITEMODE_ZA16 #undef BYTESPERPIXEL #define BYTESPERPIXEL 2 #define VALUE_TYPE GLushort #define WRITE_DEPTH( _x, _y, d ) \ *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) = d #define READ_DEPTH( d, _x, _y ) \ d = *(GLushort *)(buf + _x*BYTESPERPIXEL + _y*pitch) #define TAG(x) tdfx##x##_Z16 #include "../dri/common/depthtmp.h" /* 24 bit, depth spanline and pixel functions (for use w/ stencil) */ /* [dBorca] Hack alert: * This is evil. The incoming Mesa's 24bit depth value * is shifted left 8 bits, to obtain a full 32bit value, * which will be thrown into the framebuffer. We rely on * the fact that Voodoo hardware transforms a 32bit value * into 24bit value automatically and, MOST IMPORTANT, won't * alter the upper 8bits of the value already existing in the * framebuffer (where stencil resides). */ #undef LFB_MODE #define LFB_MODE GR_LFBWRITEMODE_Z32 #undef BYTESPERPIXEL #define BYTESPERPIXEL 4 #define VALUE_TYPE GLuint #define WRITE_DEPTH( _x, _y, d ) \ *(GLuint *)(buf + _x*BYTESPERPIXEL + _y*pitch) = d << 8 #define READ_DEPTH( d, _x, _y ) \ d = (*(GLuint *)(buf + _x*BYTESPERPIXEL + _y*pitch)) & 0xffffff #define TAG(x) tdfx##x##_Z24 #include "../dri/common/depthtmp.h" /* 32 bit, depth spanline and pixel functions (for use w/o stencil) */ /* [dBorca] Hack alert: * This is more evil. We make Mesa run in 32bit depth, but * tha Voodoo HW can only handle 24bit depth. Well, exploiting * the pixel pipeline, we can achieve 24:8 format for greater * precision... * If anyone tells me how to really store 32bit values into the * depth buffer, I'll write the *_Z32 routines. Howver, bear in * mind that means running without stencil! */ /************************************************************************/ /***** Span functions (optimized) *****/ /************************************************************************/ /* * Read a span of 15-bit RGB pixels. Note, we don't worry about cliprects * since OpenGL says obscured pixels have undefined values. */ static void fxReadRGBASpan_ARGB1555 (const GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLubyte rgba[][4]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER; GrLfbInfo_t info; info.size = sizeof(GrLfbInfo_t); if (grLfbLock(GR_LFB_READ_ONLY, currentFB, GR_LFBWRITEMODE_ANY, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info)) { const GLint winX = 0; const GLint winY = fxMesa->height - 1; const GLushort *data16 = (const GLushort *)((const GLubyte *)info.lfbPtr + (winY - y) * info.strideInBytes + (winX + x) * 2); const GLuint *data32 = (const GLuint *) data16; GLuint i, j; GLuint extraPixel = (n & 1); n -= extraPixel; for (i = j = 0; i < n; i += 2, j++) { GLuint pixel = data32[j]; rgba[i][0] = FX_rgb_scale_5[(pixel >> 10) & 0x1F]; rgba[i][1] = FX_rgb_scale_5[(pixel >> 5) & 0x1F]; rgba[i][2] = FX_rgb_scale_5[ pixel & 0x1F]; rgba[i][3] = (pixel & 0x8000) ? 255 : 0; rgba[i+1][0] = FX_rgb_scale_5[(pixel >> 26) & 0x1F]; rgba[i+1][1] = FX_rgb_scale_5[(pixel >> 21) & 0x1F]; rgba[i+1][2] = FX_rgb_scale_5[(pixel >> 16) & 0x1F]; rgba[i+1][3] = (pixel & 0x80000000) ? 255 : 0; } if (extraPixel) { GLushort pixel = data16[n]; rgba[n][0] = FX_rgb_scale_5[(pixel >> 10) & 0x1F]; rgba[n][1] = FX_rgb_scale_5[(pixel >> 5) & 0x1F]; rgba[n][2] = FX_rgb_scale_5[ pixel & 0x1F]; rgba[n][3] = (pixel & 0x8000) ? 255 : 0; } grLfbUnlock(GR_LFB_READ_ONLY, currentFB); } } /* * Read a span of 16-bit RGB pixels. Note, we don't worry about cliprects * since OpenGL says obscured pixels have undefined values. */ static void fxReadRGBASpan_RGB565 (const GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLubyte rgba[][4]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER; GrLfbInfo_t info; info.size = sizeof(GrLfbInfo_t); if (grLfbLock(GR_LFB_READ_ONLY, currentFB, GR_LFBWRITEMODE_ANY, GR_ORIGIN_UPPER_LEFT, FXFALSE, &info)) { const GLint winX = 0; const GLint winY = fxMesa->height - 1; const GLushort *data16 = (const GLushort *)((const GLubyte *)info.lfbPtr + (winY - y) * info.strideInBytes + (winX + x) * 2); const GLuint *data32 = (const GLuint *) data16; GLuint i, j; GLuint extraPixel = (n & 1); n -= extraPixel; for (i = j = 0; i < n; i += 2, j++) { GLuint pixel = data32[j]; rgba[i][0] = FX_rgb_scale_5[(pixel >> 11) & 0x1F]; rgba[i][1] = FX_rgb_scale_6[(pixel >> 5) & 0x3F]; rgba[i][2] = FX_rgb_scale_5[ pixel & 0x1F]; rgba[i][3] = 255; rgba[i+1][0] = FX_rgb_scale_5[(pixel >> 27) & 0x1F]; rgba[i+1][1] = FX_rgb_scale_6[(pixel >> 21) & 0x3F]; rgba[i+1][2] = FX_rgb_scale_5[(pixel >> 16) & 0x1F]; rgba[i+1][3] = 255; } if (extraPixel) { GLushort pixel = data16[n]; rgba[n][0] = FX_rgb_scale_5[(pixel >> 11) & 0x1F]; rgba[n][1] = FX_rgb_scale_6[(pixel >> 5) & 0x3F]; rgba[n][2] = FX_rgb_scale_5[ pixel & 0x1F]; rgba[n][3] = 255; } grLfbUnlock(GR_LFB_READ_ONLY, currentFB); } } /* * Read a span of 32-bit RGB pixels. Note, we don't worry about cliprects * since OpenGL says obscured pixels have undefined values. */ static void fxReadRGBASpan_ARGB8888 (const GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLubyte rgba[][4]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GrBuffer_t currentFB = GR_BUFFER_BACKBUFFER; GLuint i; grLfbReadRegion(currentFB, x, fxMesa->height - 1 - y, n, 1, n * 4, rgba); for (i = 0; i < n; i++) { GLubyte c = rgba[i][0]; rgba[i][0] = rgba[i][2]; rgba[i][2] = c; } } /************************************************************************/ /***** Depth functions (optimized) *****/ /************************************************************************/ static void fxReadDepthSpan_Z16(GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLuint depth[]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GLint bottom = fxMesa->height - 1; GLushort depth16[MAX_WIDTH]; GLuint i; if (TDFX_DEBUG & VERBOSE_DRIVER) { fprintf(stderr, "fxReadDepthSpan_Z16(...)\n"); } grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, depth16); for (i = 0; i < n; i++) { depth[i] = depth16[i]; } } static void fxReadDepthSpan_Z24(GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLuint depth[]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GLint bottom = fxMesa->height - 1; GLuint i; if (TDFX_DEBUG & VERBOSE_DRIVER) { fprintf(stderr, "fxReadDepthSpan_Z24(...)\n"); } grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, depth); for (i = 0; i < n; i++) { depth[i] &= 0xffffff; } } /************************************************************************/ /***** Stencil functions (optimized) *****/ /************************************************************************/ static void fxWriteStencilSpan (GLcontext *ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, const GLstencil stencil[], const GLubyte mask[]) { /* * XXX todo */ } static void fxReadStencilSpan(GLcontext * ctx, struct gl_renderbuffer *rb, GLuint n, GLint x, GLint y, GLstencil stencil[]) { fxMesaContext fxMesa = FX_CONTEXT(ctx); GLint bottom = fxMesa->height - 1; GLuint zs32[MAX_WIDTH]; GLuint i; if (TDFX_DEBUG & VERBOSE_DRIVER) { fprintf(stderr, "fxReadStencilSpan(...)\n"); } grLfbReadRegion(GR_BUFFER_AUXBUFFER, x, bottom - y, n, 1, 0, zs32); for (i = 0; i < n; i++) { stencil[i] = zs32[i] >> 24; } } static void fxWriteStencilPixels (GLcontext *ctx, struct gl_renderbuffer *rb, GLuint n, const GLint x[], const GLint y[], const GLstencil stencil[], const GLubyte mask[]) { /* * XXX todo */ } static void fxReadStencilPixels (GLcontext *ctx, struct gl_renderbuffer *rb, GLuint n, const GLint x[], const GLint y[], GLstencil stencil[]) { /* * XXX todo */ } void fxSetupDDSpanPointers(GLcontext * ctx) { struct swrast_device_driver *swdd = _swrast_GetDeviceDriverReference( ctx ); fxMesaContext fxMesa = FX_CONTEXT(ctx); switch (fxMesa->colDepth) { case 15: swdd->WriteRGBASpan = tdfxWriteRGBASpan_ARGB1555; swdd->WriteRGBSpan = tdfxWriteRGBSpan_ARGB1555; swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_ARGB1555; swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_ARGB1555; swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_ARGB1555; swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_ARGB1555; swdd->ReadRGBAPixels = tdfxReadRGBAPixels_ARGB1555; swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z16; swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z16; swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z16; swdd->ReadDepthPixels = tdfxReadDepthPixels_Z16; break; case 16: swdd->WriteRGBASpan = tdfxWriteRGBASpan_RGB565; swdd->WriteRGBSpan = tdfxWriteRGBSpan_RGB565; swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_RGB565; swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_RGB565; swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_RGB565; swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_RGB565; swdd->ReadRGBAPixels = tdfxReadRGBAPixels_RGB565; swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z16; swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z16; swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z16; swdd->ReadDepthPixels = tdfxReadDepthPixels_Z16; break; case 32: swdd->WriteRGBASpan = tdfxWriteRGBASpan_ARGB8888; swdd->WriteRGBSpan = tdfxWriteRGBSpan_ARGB8888; swdd->WriteRGBAPixels = tdfxWriteRGBAPixels_ARGB8888; swdd->WriteMonoRGBASpan = tdfxWriteMonoRGBASpan_ARGB8888; swdd->WriteMonoRGBAPixels = tdfxWriteMonoRGBAPixels_ARGB8888; swdd->ReadRGBASpan = /*td*/fxReadRGBASpan_ARGB8888; swdd->ReadRGBAPixels = tdfxReadRGBAPixels_ARGB8888; swdd->WriteDepthSpan = tdfxWriteDepthSpan_Z24; swdd->WriteDepthPixels = tdfxWriteDepthPixels_Z24; swdd->ReadDepthSpan = /*td*/fxReadDepthSpan_Z24; swdd->ReadDepthPixels = tdfxReadDepthPixels_Z24; break; } if (fxMesa->haveHwStencil) { swdd->WriteStencilSpan = fxWriteStencilSpan; swdd->ReadStencilSpan = fxReadStencilSpan; swdd->WriteStencilPixels = fxWriteStencilPixels; swdd->ReadStencilPixels = fxReadStencilPixels; } #if 0 swdd->WriteCI8Span = NULL; swdd->WriteCI32Span = NULL; swdd->WriteMonoCISpan = NULL; swdd->WriteCI32Pixels = NULL; swdd->WriteMonoCIPixels = NULL; swdd->ReadCI32Span = NULL; swdd->ReadCI32Pixels = NULL; swdd->SpanRenderStart = tdfxSpanRenderStart; /* BEGIN_BOARD_LOCK */ swdd->SpanRenderFinish = tdfxSpanRenderFinish; /* END_BOARD_LOCK */ #endif } #else /* * Need this to provide at least one external definition. */ extern int gl_fx_dummy_function_span(void); int gl_fx_dummy_function_span(void) { return 0; } #endif /* FX */