0,0 → 1,402 |
/* |
* Mesa 3-D graphics library |
* |
* 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 |
* THE AUTHORS OR COPYRIGHT HOLDERS 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[VARYING_SLOT_POS][0]; |
GLint x1 = (GLint) vert1->attrib[VARYING_SLOT_POS][0]; |
GLint y0 = (GLint) vert0->attrib[VARYING_SLOT_POS][1]; |
GLint y1 = (GLint) vert1->attrib[VARYING_SLOT_POS][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[VARYING_SLOT_POS][0] + vert0->attrib[VARYING_SLOT_POS][1] |
+ vert1->attrib[VARYING_SLOT_POS][0] + vert1->attrib[VARYING_SLOT_POS][1]; |
if (IS_INF_OR_NAN(tmp)) |
return; |
} |
|
/* |
printf("%s():\n", __func__); |
printf(" (%f, %f, %f) -> (%f, %f, %f)\n", |
vert0->attrib[VARYING_SLOT_POS][0], |
vert0->attrib[VARYING_SLOT_POS][1], |
vert0->attrib[VARYING_SLOT_POS][2], |
vert1->attrib[VARYING_SLOT_POS][0], |
vert1->attrib[VARYING_SLOT_POS][1], |
vert1->attrib[VARYING_SLOT_POS][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", __func__, dx, dy, |
vert0->attrib[VARYING_SLOT_COL1][0], |
vert0->attrib[VARYING_SLOT_COL1][1], |
vert0->attrib[VARYING_SLOT_COL1][2], |
vert0->attrib[VARYING_SLOT_COL1][3], |
vert1->attrib[VARYING_SLOT_COL1][0], |
vert1->attrib[VARYING_SLOT_COL1][1], |
vert1->attrib[VARYING_SLOT_COL1][2], |
vert1->attrib[VARYING_SLOT_COL1][3]); |
*/ |
|
#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[VARYING_SLOT_POS][2]) + FIXED_HALF; |
span.zStep = FloatToFixed( vert1->attrib[VARYING_SLOT_POS][2] |
- vert0->attrib[VARYING_SLOT_POS][2]) / numPixels; |
} |
else { |
/* don't use fixed point */ |
span.z = (GLuint) vert0->attrib[VARYING_SLOT_POS][2]; |
span.zStep = (GLint) (( vert1->attrib[VARYING_SLOT_POS][2] |
- vert0->attrib[VARYING_SLOT_POS][2]) / numPixels); |
} |
} |
#endif |
#if defined(INTERP_ATTRIBS) |
{ |
const GLfloat invLen = 1.0F / numPixels; |
const GLfloat invw0 = vert0->attrib[VARYING_SLOT_POS][3]; |
const GLfloat invw1 = vert1->attrib[VARYING_SLOT_POS][3]; |
|
span.attrStart[VARYING_SLOT_POS][3] = invw0; |
span.attrStepX[VARYING_SLOT_POS][3] = (invw1 - invw0) * invLen; |
span.attrStepY[VARYING_SLOT_POS][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_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 |