+++ /dev/null
-/*
- * 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_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( struct gl_context *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;
-#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;
-
-#ifdef DEPTH_TYPE
- zPtr = (DEPTH_TYPE *) _swrast_pixel_address(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.
- */
- 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;
- }
-#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;
-
-
- /*
- * 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_ATTRIBS
-#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