| /* |
| * Mesa 3-D graphics library |
| * Version: 7.0 |
| * |
| * Copyright (C) 1999-2007 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. |
| */ |
| |
| |
| /* |
| * Line Rasterizer Template |
| * |
| * This file is #include'd to generate custom line rasterizers. |
| * |
| * The following macros may be defined to indicate what auxillary information |
| * must be interplated along the line: |
| * INTERP_Z - if defined, interpolate Z values |
| * INTERP_RGBA - if defined, interpolate RGBA values |
| * INTERP_INDEX - if defined, interpolate color index values |
| * INTERP_ATTRIBS - if defined, interpolate attribs (texcoords, varying, etc) |
| * |
| * When one can directly address pixels in the color buffer the following |
| * macros can be defined and used to directly compute pixel addresses during |
| * rasterization (see pixelPtr): |
| * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint) |
| * BYTES_PER_ROW - number of bytes per row in the color buffer |
| * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where |
| * Y==0 at bottom of screen and increases upward. |
| * |
| * Similarly, for direct depth buffer access, this type is used for depth |
| * buffer addressing: |
| * DEPTH_TYPE - either GLushort or GLuint |
| * |
| * Optionally, one may provide one-time setup code |
| * SETUP_CODE - code which is to be executed once per line |
| * |
| * To actually "plot" each pixel the PLOT macro must be defined... |
| * PLOT(X,Y) - code to plot a pixel. Example: |
| * if (Z < *zPtr) { |
| * *zPtr = Z; |
| * color = pack_rgb( FixedToInt(r0), FixedToInt(g0), |
| * FixedToInt(b0) ); |
| * put_pixel( X, Y, color ); |
| * } |
| * |
| * This code was designed for the origin to be in the lower-left corner. |
| * |
| */ |
| |
| |
| static void |
| NAME( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 ) |
| { |
| const SWcontext *swrast = SWRAST_CONTEXT(ctx); |
| SWspan span; |
| GLuint interpFlags = 0; |
| GLint x0 = (GLint) vert0->attrib[FRAG_ATTRIB_WPOS][0]; |
| GLint x1 = (GLint) vert1->attrib[FRAG_ATTRIB_WPOS][0]; |
| GLint y0 = (GLint) vert0->attrib[FRAG_ATTRIB_WPOS][1]; |
| GLint y1 = (GLint) vert1->attrib[FRAG_ATTRIB_WPOS][1]; |
| GLint dx, dy; |
| GLint numPixels; |
| GLint xstep, ystep; |
| #if defined(DEPTH_TYPE) |
| const GLint depthBits = ctx->DrawBuffer->Visual.depthBits; |
| const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0; |
| struct gl_renderbuffer *zrb = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer; |
| #define FixedToDepth(F) ((F) >> fixedToDepthShift) |
| GLint zPtrXstep, zPtrYstep; |
| DEPTH_TYPE *zPtr; |
| #elif defined(INTERP_Z) |
| const GLint depthBits = ctx->DrawBuffer->Visual.depthBits; |
| /*ctx->Visual.depthBits;*/ |
| #endif |
| #ifdef PIXEL_ADDRESS |
| PIXEL_TYPE *pixelPtr; |
| GLint pixelXstep, pixelYstep; |
| #endif |
| |
| #ifdef SETUP_CODE |
| SETUP_CODE |
| #endif |
| |
| (void) swrast; |
| |
| /* Cull primitives with malformed coordinates. |
| */ |
| { |
| GLfloat tmp = vert0->attrib[FRAG_ATTRIB_WPOS][0] + vert0->attrib[FRAG_ATTRIB_WPOS][1] |
| + vert1->attrib[FRAG_ATTRIB_WPOS][0] + vert1->attrib[FRAG_ATTRIB_WPOS][1]; |
| if (IS_INF_OR_NAN(tmp)) |
| return; |
| } |
| |
| /* |
| printf("%s():\n", __FUNCTION__); |
| printf(" (%f, %f, %f) -> (%f, %f, %f)\n", |
| vert0->attrib[FRAG_ATTRIB_WPOS][0], |
| vert0->attrib[FRAG_ATTRIB_WPOS][1], |
| vert0->attrib[FRAG_ATTRIB_WPOS][2], |
| vert1->attrib[FRAG_ATTRIB_WPOS][0], |
| vert1->attrib[FRAG_ATTRIB_WPOS][1], |
| vert1->attrib[FRAG_ATTRIB_WPOS][2]); |
| printf(" (%d, %d, %d) -> (%d, %d, %d)\n", |
| vert0->color[0], vert0->color[1], vert0->color[2], |
| vert1->color[0], vert1->color[1], vert1->color[2]); |
| printf(" (%d, %d, %d) -> (%d, %d, %d)\n", |
| vert0->specular[0], vert0->specular[1], vert0->specular[2], |
| vert1->specular[0], vert1->specular[1], vert1->specular[2]); |
| */ |
| |
| /* |
| * Despite being clipped to the view volume, the line's window coordinates |
| * may just lie outside the window bounds. That is, if the legal window |
| * coordinates are [0,W-1][0,H-1], it's possible for x==W and/or y==H. |
| * This quick and dirty code nudges the endpoints inside the window if |
| * necessary. |
| */ |
| #ifdef CLIP_HACK |
| { |
| GLint w = ctx->DrawBuffer->Width; |
| GLint h = ctx->DrawBuffer->Height; |
| if ((x0==w) | (x1==w)) { |
| if ((x0==w) & (x1==w)) |
| return; |
| x0 -= x0==w; |
| x1 -= x1==w; |
| } |
| if ((y0==h) | (y1==h)) { |
| if ((y0==h) & (y1==h)) |
| return; |
| y0 -= y0==h; |
| y1 -= y1==h; |
| } |
| } |
| #endif |
| |
| dx = x1 - x0; |
| dy = y1 - y0; |
| if (dx == 0 && dy == 0) |
| return; |
| |
| /* |
| printf("%s %d,%d %g %g %g %g %g %g %g %g\n", __FUNCTION__, dx, dy, |
| vert0->attrib[FRAG_ATTRIB_COL1][0], |
| vert0->attrib[FRAG_ATTRIB_COL1][1], |
| vert0->attrib[FRAG_ATTRIB_COL1][2], |
| vert0->attrib[FRAG_ATTRIB_COL1][3], |
| vert1->attrib[FRAG_ATTRIB_COL1][0], |
| vert1->attrib[FRAG_ATTRIB_COL1][1], |
| vert1->attrib[FRAG_ATTRIB_COL1][2], |
| vert1->attrib[FRAG_ATTRIB_COL1][3]); |
| */ |
| |
| #ifdef DEPTH_TYPE |
| zPtr = (DEPTH_TYPE *) zrb->GetPointer(ctx, zrb, x0, y0); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelPtr = (PIXEL_TYPE *) PIXEL_ADDRESS(x0,y0); |
| #endif |
| |
| if (dx<0) { |
| dx = -dx; /* make positive */ |
| xstep = -1; |
| #ifdef DEPTH_TYPE |
| zPtrXstep = -((GLint)sizeof(DEPTH_TYPE)); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelXstep = -((GLint)sizeof(PIXEL_TYPE)); |
| #endif |
| } |
| else { |
| xstep = 1; |
| #ifdef DEPTH_TYPE |
| zPtrXstep = ((GLint)sizeof(DEPTH_TYPE)); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelXstep = ((GLint)sizeof(PIXEL_TYPE)); |
| #endif |
| } |
| |
| if (dy<0) { |
| dy = -dy; /* make positive */ |
| ystep = -1; |
| #ifdef DEPTH_TYPE |
| zPtrYstep = -((GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE))); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelYstep = BYTES_PER_ROW; |
| #endif |
| } |
| else { |
| ystep = 1; |
| #ifdef DEPTH_TYPE |
| zPtrYstep = (GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE)); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelYstep = -(BYTES_PER_ROW); |
| #endif |
| } |
| |
| ASSERT(dx >= 0); |
| ASSERT(dy >= 0); |
| |
| numPixels = MAX2(dx, dy); |
| |
| /* |
| * Span setup: compute start and step values for all interpolated values. |
| */ |
| #ifdef INTERP_RGBA |
| interpFlags |= SPAN_RGBA; |
| if (ctx->Light.ShadeModel == GL_SMOOTH) { |
| span.red = ChanToFixed(vert0->color[0]); |
| span.green = ChanToFixed(vert0->color[1]); |
| span.blue = ChanToFixed(vert0->color[2]); |
| span.alpha = ChanToFixed(vert0->color[3]); |
| span.redStep = (ChanToFixed(vert1->color[0]) - span.red ) / numPixels; |
| span.greenStep = (ChanToFixed(vert1->color[1]) - span.green) / numPixels; |
| span.blueStep = (ChanToFixed(vert1->color[2]) - span.blue ) / numPixels; |
| span.alphaStep = (ChanToFixed(vert1->color[3]) - span.alpha) / numPixels; |
| } |
| else { |
| span.red = ChanToFixed(vert1->color[0]); |
| span.green = ChanToFixed(vert1->color[1]); |
| span.blue = ChanToFixed(vert1->color[2]); |
| span.alpha = ChanToFixed(vert1->color[3]); |
| span.redStep = 0; |
| span.greenStep = 0; |
| span.blueStep = 0; |
| span.alphaStep = 0; |
| } |
| #endif |
| #ifdef INTERP_INDEX |
| interpFlags |= SPAN_INDEX; |
| if (ctx->Light.ShadeModel == GL_SMOOTH) { |
| span.index = FloatToFixed(vert0->attrib[FRAG_ATTRIB_CI][0]); |
| span.indexStep = FloatToFixed( vert1->attrib[FRAG_ATTRIB_CI][0] |
| - vert0->attrib[FRAG_ATTRIB_CI][0]) / numPixels; |
| } |
| else { |
| span.index = FloatToFixed(vert1->attrib[FRAG_ATTRIB_CI][0]); |
| span.indexStep = 0; |
| } |
| #endif |
| #if defined(INTERP_Z) || defined(DEPTH_TYPE) |
| interpFlags |= SPAN_Z; |
| { |
| if (depthBits <= 16) { |
| span.z = FloatToFixed(vert0->attrib[FRAG_ATTRIB_WPOS][2]) + FIXED_HALF; |
| span.zStep = FloatToFixed( vert1->attrib[FRAG_ATTRIB_WPOS][2] |
| - vert0->attrib[FRAG_ATTRIB_WPOS][2]) / numPixels; |
| } |
| else { |
| /* don't use fixed point */ |
| span.z = (GLuint) vert0->attrib[FRAG_ATTRIB_WPOS][2]; |
| span.zStep = (GLint) (( vert1->attrib[FRAG_ATTRIB_WPOS][2] |
| - vert0->attrib[FRAG_ATTRIB_WPOS][2]) / numPixels); |
| } |
| } |
| #endif |
| #if defined(INTERP_ATTRIBS) |
| { |
| const GLfloat invLen = 1.0F / numPixels; |
| const GLfloat invw0 = vert0->attrib[FRAG_ATTRIB_WPOS][3]; |
| const GLfloat invw1 = vert1->attrib[FRAG_ATTRIB_WPOS][3]; |
| |
| span.attrStart[FRAG_ATTRIB_WPOS][3] = invw0; |
| span.attrStepX[FRAG_ATTRIB_WPOS][3] = (invw1 - invw0) * invLen; |
| span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0; |
| |
| ATTRIB_LOOP_BEGIN |
| if (swrast->_InterpMode[attr] == GL_FLAT) { |
| COPY_4V(span.attrStart[attr], vert1->attrib[attr]); |
| ASSIGN_4V(span.attrStepX[attr], 0.0, 0.0, 0.0, 0.0); |
| } |
| else { |
| GLuint c; |
| for (c = 0; c < 4; c++) { |
| float da; |
| span.attrStart[attr][c] = invw0 * vert0->attrib[attr][c]; |
| da = (invw1 * vert1->attrib[attr][c]) - span.attrStart[attr][c]; |
| span.attrStepX[attr][c] = da * invLen; |
| } |
| } |
| ASSIGN_4V(span.attrStepY[attr], 0.0, 0.0, 0.0, 0.0); |
| ATTRIB_LOOP_END |
| } |
| #endif |
| |
| INIT_SPAN(span, GL_LINE); |
| span.end = numPixels; |
| span.interpMask = interpFlags; |
| span.arrayMask = SPAN_XY; |
| |
| span.facing = swrast->PointLineFacing; |
| |
| |
| /* |
| * Draw |
| */ |
| |
| if (dx > dy) { |
| /*** X-major line ***/ |
| GLint i; |
| GLint errorInc = dy+dy; |
| GLint error = errorInc-dx; |
| GLint errorDec = error-dx; |
| |
| for (i = 0; i < dx; i++) { |
| #ifdef DEPTH_TYPE |
| GLuint Z = FixedToDepth(span.z); |
| #endif |
| #ifdef PLOT |
| PLOT( x0, y0 ); |
| #else |
| span.array->x[i] = x0; |
| span.array->y[i] = y0; |
| #endif |
| x0 += xstep; |
| #ifdef DEPTH_TYPE |
| zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); |
| span.z += span.zStep; |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); |
| #endif |
| if (error < 0) { |
| error += errorInc; |
| } |
| else { |
| error += errorDec; |
| y0 += ystep; |
| #ifdef DEPTH_TYPE |
| zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); |
| #endif |
| } |
| } |
| } |
| else { |
| /*** Y-major line ***/ |
| GLint i; |
| GLint errorInc = dx+dx; |
| GLint error = errorInc-dy; |
| GLint errorDec = error-dy; |
| |
| for (i=0;i<dy;i++) { |
| #ifdef DEPTH_TYPE |
| GLuint Z = FixedToDepth(span.z); |
| #endif |
| #ifdef PLOT |
| PLOT( x0, y0 ); |
| #else |
| span.array->x[i] = x0; |
| span.array->y[i] = y0; |
| #endif |
| y0 += ystep; |
| #ifdef DEPTH_TYPE |
| zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); |
| span.z += span.zStep; |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); |
| #endif |
| if (error<0) { |
| error += errorInc; |
| } |
| else { |
| error += errorDec; |
| x0 += xstep; |
| #ifdef DEPTH_TYPE |
| zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); |
| #endif |
| #ifdef PIXEL_ADDRESS |
| pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); |
| #endif |
| } |
| } |
| } |
| |
| #ifdef RENDER_SPAN |
| RENDER_SPAN( span ); |
| #endif |
| |
| (void)span; |
| |
| } |
| |
| |
| #undef NAME |
| #undef INTERP_Z |
| #undef INTERP_RGBA |
| #undef INTERP_ATTRIBS |
| #undef INTERP_INDEX |
| #undef PIXEL_ADDRESS |
| #undef PIXEL_TYPE |
| #undef DEPTH_TYPE |
| #undef BYTES_PER_ROW |
| #undef SETUP_CODE |
| #undef PLOT |
| #undef CLIP_HACK |
| #undef FixedToDepth |
| #undef RENDER_SPAN |
