/*
* 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.
*/
#include "main/framebuffer.h"
#include "main/glheader.h"
#include "main/macros.h"
#include "s_context.h"
#include "s_feedback.h"
#include "s_points.h"
#include "s_span.h"
/**
* Used to cull points with invalid coords
*/
#define CULL_INVALID(V) \
do { \
float tmp = (V)->attrib[VARYING_SLOT_POS][0] \
+ (V)->attrib[VARYING_SLOT_POS][1]; \
if (IS_INF_OR_NAN(tmp)) \
return; \
} while(0)
/**
* Get/compute the point size.
* The size may come from a vertex shader, or computed with attentuation
* or just the glPointSize value.
* Must also clamp to user-defined range and implmentation limits.
*/
static inline GLfloat
get_size(const struct gl_context *ctx, const SWvertex *vert, GLboolean smoothed)
{
GLfloat size;
if (ctx->Point._Attenuated || ctx->VertexProgram.PointSizeEnabled) {
/* use vertex's point size */
size = vert->pointSize;
}
else {
/* use constant point size */
size = ctx->Point.Size;
}
/* always clamp to user-specified limits */
size = CLAMP(size, ctx->Point.MinSize, ctx->Point.MaxSize);
/* clamp to implementation limits */
if (smoothed)
size = CLAMP(size, ctx->Const.MinPointSizeAA, ctx->Const.MaxPointSizeAA);
else
size = CLAMP(size, ctx->Const.MinPointSize, ctx->Const.MaxPointSize);
return size;
}
/**
* Draw a point sprite
*/
static void
sprite_point(struct gl_context *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
SWspan span;
GLfloat size;
GLuint tCoords[MAX_TEXTURE_COORD_UNITS + 1];
GLuint numTcoords = 0;
GLfloat t0, dtdy;
CULL_INVALID(vert);
/* z coord */
if (ctx->DrawBuffer->Visual.depthBits <= 16)
span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
span.zStep = 0;
size = get_size(ctx, vert, GL_FALSE);
/* span init */
INIT_SPAN(span, GL_POINT);
span.interpMask = SPAN_Z | SPAN_RGBA;
span.facing = swrast->PointLineFacing;
span.red = ChanToFixed(vert->color[0]);
span.green = ChanToFixed(vert->color[1]);
span.blue = ChanToFixed(vert->color[2]);
span.alpha = ChanToFixed(vert->color[3]);
span.redStep = 0;
span.greenStep = 0;
span.blueStep = 0;
span.alphaStep = 0;
/* need these for fragment programs */
span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
{
GLfloat s, r, dsdx;
/* texcoord / pointcoord interpolants */
s = 0.0F;
dsdx = 1.0F / size;
if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) {
dtdy = 1.0F / size;
t0 = 0.5F * dtdy;
}
else {
/* GL_UPPER_LEFT */
dtdy = -1.0F / size;
t0 = 1.0F + 0.5F * dtdy;
}
ATTRIB_LOOP_BEGIN
if (attr >= VARYING_SLOT_TEX0 && attr <= VARYING_SLOT_TEX7) {
/* a texcoord attribute */
const GLuint u = attr - VARYING_SLOT_TEX0;
assert(u < MAX_TEXTURE_COORD_UNITS);
if (ctx->Point.CoordReplace & (1u << u)) {
tCoords[numTcoords++] = attr;
if (ctx->Point.SpriteRMode == GL_ZERO)
r = 0.0F;
else if (ctx->Point.SpriteRMode == GL_S)
r = vert->attrib[attr][0];
else /* GL_R */
r = vert->attrib[attr][2];
span.attrStart[attr][0] = s;
span.attrStart[attr][1] = 0.0; /* overwritten below */
span.attrStart[attr][2] = r;
span.attrStart[attr][3] = 1.0;
span.attrStepX[attr][0] = dsdx;
span.attrStepX[attr][1] = 0.0;
span.attrStepX[attr][2] = 0.0;
span.attrStepX[attr][3] = 0.0;
span.attrStepY[attr][0] = 0.0;
span.attrStepY[attr][1] = dtdy;
span.attrStepY[attr][2] = 0.0;
span.attrStepY[attr][3] = 0.0;
continue;
}
}
else if (attr == VARYING_SLOT_PNTC) {
/* GLSL gl_PointCoord.xy (.zw undefined) */
span.attrStart[VARYING_SLOT_PNTC][0] = 0.0;
span.attrStart[VARYING_SLOT_PNTC][1] = 0.0; /* t0 set below */
span.attrStepX[VARYING_SLOT_PNTC][0] = dsdx;
span.attrStepX[VARYING_SLOT_PNTC][1] = 0.0;
span.attrStepY[VARYING_SLOT_PNTC][0] = 0.0;
span.attrStepY[VARYING_SLOT_PNTC][1] = dtdy;
tCoords[numTcoords++] = VARYING_SLOT_PNTC;
continue;
}
/* use vertex's texcoord/attrib */
COPY_4V(span.attrStart[attr], vert->attrib[attr]);
ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
ATTRIB_LOOP_END;
}
/* compute pos, bounds and render */
{
const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
GLint iSize = (GLint) (size + 0.5F);
GLint xmin, xmax, ymin, ymax, iy;
GLint iRadius;
GLfloat tcoord = t0;
iSize = MAX2(1, iSize);
iRadius = iSize / 2;
if (iSize & 1) {
/* odd size */
xmin = (GLint) (x - iRadius);
xmax = (GLint) (x + iRadius);
ymin = (GLint) (y - iRadius);
ymax = (GLint) (y + iRadius);
}
else {
/* even size */
/* 0.501 factor allows conformance to pass */
xmin = (GLint) (x + 0.501F) - iRadius;
xmax = xmin + iSize - 1;
ymin = (GLint) (y + 0.501F) - iRadius;
ymax = ymin + iSize - 1;
}
/* render spans */
for (iy = ymin; iy <= ymax; iy++) {
GLuint i;
/* setup texcoord T for this row */
for (i = 0; i < numTcoords; i++) {
span.attrStart[tCoords[i]][1] = tcoord;
}
/* these might get changed by span clipping */
span.x = xmin;
span.y = iy;
span.end = xmax - xmin + 1;
_swrast_write_rgba_span(ctx, &span);
tcoord += dtdy;
}
}
}
/**
* Draw smooth/antialiased point. RGB or CI mode.
*/
static void
smooth_point(struct gl_context *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
SWspan span;
GLfloat size, alphaAtten;
CULL_INVALID(vert);
/* z coord */
if (ctx->DrawBuffer->Visual.depthBits <= 16)
span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
span.zStep = 0;
size = get_size(ctx, vert, GL_TRUE);
/* alpha attenuation / fade factor */
if (_mesa_is_multisample_enabled(ctx)) {
if (vert->pointSize >= ctx->Point.Threshold) {
alphaAtten = 1.0F;
}
else {
GLfloat dsize = vert->pointSize / ctx->Point.Threshold;
alphaAtten = dsize * dsize;
}
}
else {
alphaAtten = 1.0;
}
(void) alphaAtten; /* not used */
/* span init */
INIT_SPAN(span, GL_POINT);
span.interpMask = SPAN_Z | SPAN_RGBA;
span.arrayMask = SPAN_COVERAGE | SPAN_MASK;
span.facing = swrast->PointLineFacing;
span.red = ChanToFixed(vert->color[0]);
span.green = ChanToFixed(vert->color[1]);
span.blue = ChanToFixed(vert->color[2]);
span.alpha = ChanToFixed(vert->color[3]);
span.redStep = 0;
span.greenStep = 0;
span.blueStep = 0;
span.alphaStep = 0;
/* need these for fragment programs */
span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
ATTRIB_LOOP_BEGIN
COPY_4V(span.attrStart[attr], vert->attrib[attr]);
ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
ATTRIB_LOOP_END
/* compute pos, bounds and render */
{
const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
const GLfloat radius = 0.5F * size;
const GLfloat rmin = radius - 0.7071F; /* 0.7071 = sqrt(2)/2 */
const GLfloat rmax = radius + 0.7071F;
const GLfloat rmin2 = MAX2(0.0F, rmin * rmin);
const GLfloat rmax2 = rmax * rmax;
const GLfloat cscale = 1.0F / (rmax2 - rmin2);
const GLint xmin = (GLint) (x - radius);
const GLint xmax = (GLint) (x + radius);
const GLint ymin = (GLint) (y - radius);
const GLint ymax = (GLint) (y + radius);
GLint ix, iy;
for (iy = ymin; iy <= ymax; iy++) {
/* these might get changed by span clipping */
span.x = xmin;
span.y = iy;
span.end = xmax - xmin + 1;
/* compute coverage for each pixel in span */
for (ix = xmin; ix <= xmax; ix++) {
const GLfloat dx = ix - x + 0.5F;
const GLfloat dy = iy - y + 0.5F;
const GLfloat dist2 = dx * dx + dy * dy;
GLfloat coverage;
if (dist2 < rmax2) {
if (dist2 >= rmin2) {
/* compute partial coverage */
coverage = 1.0F - (dist2 - rmin2) * cscale;
}
else {
/* full coverage */
coverage = 1.0F;
}
span.array->mask[ix - xmin] = 1;
}
else {
/* zero coverage - fragment outside the radius */
coverage = 0.0;
span.array->mask[ix - xmin] = 0;
}
span.array->coverage[ix - xmin] = coverage;
}
/* render span */
_swrast_write_rgba_span(ctx, &span);
}
}
}
/**
* Draw large (size >= 1) non-AA point. RGB or CI mode.
*/
static void
large_point(struct gl_context *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
SWspan span;
GLfloat size;
CULL_INVALID(vert);
/* z coord */
if (ctx->DrawBuffer->Visual.depthBits <= 16)
span.z = FloatToFixed(vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
span.zStep = 0;
size = get_size(ctx, vert, GL_FALSE);
/* span init */
INIT_SPAN(span, GL_POINT);
span.arrayMask = SPAN_XY;
span.facing = swrast->PointLineFacing;
span.interpMask = SPAN_Z | SPAN_RGBA;
span.red = ChanToFixed(vert->color[0]);
span.green = ChanToFixed(vert->color[1]);
span.blue = ChanToFixed(vert->color[2]);
span.alpha = ChanToFixed(vert->color[3]);
span.redStep = 0;
span.greenStep = 0;
span.blueStep = 0;
span.alphaStep = 0;
/* need these for fragment programs */
span.attrStart[VARYING_SLOT_POS][3] = 1.0F;
span.attrStepX[VARYING_SLOT_POS][3] = 0.0F;
span.attrStepY[VARYING_SLOT_POS][3] = 0.0F;
ATTRIB_LOOP_BEGIN
COPY_4V(span.attrStart[attr], vert->attrib[attr]);
ASSIGN_4V(span.attrStepX[attr], 0, 0, 0, 0);
ASSIGN_4V(span.attrStepY[attr], 0, 0, 0, 0);
ATTRIB_LOOP_END
/* compute pos, bounds and render */
{
const GLfloat x = vert->attrib[VARYING_SLOT_POS][0];
const GLfloat y = vert->attrib[VARYING_SLOT_POS][1];
GLint iSize = (GLint) (size + 0.5F);
GLint xmin, xmax, ymin, ymax, ix, iy;
GLint iRadius;
iSize = MAX2(1, iSize);
iRadius = iSize / 2;
if (iSize & 1) {
/* odd size */
xmin = (GLint) (x - iRadius);
xmax = (GLint) (x + iRadius);
ymin = (GLint) (y - iRadius);
ymax = (GLint) (y + iRadius);
}
else {
/* even size */
/* 0.501 factor allows conformance to pass */
xmin = (GLint) (x + 0.501F) - iRadius;
xmax = xmin + iSize - 1;
ymin = (GLint) (y + 0.501F) - iRadius;
ymax = ymin + iSize - 1;
}
/* generate fragments */
span.end = 0;
for (iy = ymin; iy <= ymax; iy++) {
for (ix = xmin; ix <= xmax; ix++) {
span.array->x[span.end] = ix;
span.array->y[span.end] = iy;
span.end++;
}
}
assert(span.end <= SWRAST_MAX_WIDTH);
_swrast_write_rgba_span(ctx, &span);
}
}
/**
* Draw size=1, single-pixel point
*/
static void
pixel_point(struct gl_context *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
/*
* Note that unlike the other functions, we put single-pixel points
* into a special span array in order to render as many points as
* possible with a single _swrast_write_rgba_span() call.
*/
SWspan *span = &(swrast->PointSpan);
GLuint count;
CULL_INVALID(vert);
/* Span init */
span->interpMask = 0;
span->arrayMask = SPAN_XY | SPAN_Z;
span->arrayMask |= SPAN_RGBA;
/*span->arrayMask |= SPAN_LAMBDA;*/
span->arrayAttribs = swrast->_ActiveAttribMask; /* we'll produce these vals */
/* need these for fragment programs */
span->attrStart[VARYING_SLOT_POS][3] = 1.0F;
span->attrStepX[VARYING_SLOT_POS][3] = 0.0F;
span->attrStepY[VARYING_SLOT_POS][3] = 0.0F;
/* check if we need to flush */
if (span->end >= SWRAST_MAX_WIDTH ||
(swrast->_RasterMask & (BLEND_BIT | LOGIC_OP_BIT | MASKING_BIT)) ||
span->facing != swrast->PointLineFacing) {
if (span->end > 0) {
_swrast_write_rgba_span(ctx, span);
span->end = 0;
}
}
count = span->end;
span->facing = swrast->PointLineFacing;
/* fragment attributes */
span->array->rgba[count][RCOMP] = vert->color[0];
span->array->rgba[count][GCOMP] = vert->color[1];
span->array->rgba[count][BCOMP] = vert->color[2];
span->array->rgba[count][ACOMP] = vert->color[3];
ATTRIB_LOOP_BEGIN
COPY_4V(span->array->attribs[attr][count], vert->attrib[attr]);
ATTRIB_LOOP_END
/* fragment position */
span->array->x[count] = (GLint) vert->attrib[VARYING_SLOT_POS][0];
span->array->y[count] = (GLint) vert->attrib[VARYING_SLOT_POS][1];
span->array->z[count] = (GLint) (vert->attrib[VARYING_SLOT_POS][2] + 0.5F);
span->end = count + 1;
assert(span->end <= SWRAST_MAX_WIDTH);
}
/**
* Add specular color to primary color, draw point, restore original
* primary color.
*/
void
_swrast_add_spec_terms_point(struct gl_context *ctx, const SWvertex *v0)
{
SWvertex *ncv0 = (SWvertex *) v0; /* cast away const */
GLfloat rSum, gSum, bSum;
GLchan cSave[4];
/* save */
COPY_CHAN4(cSave, ncv0->color);
/* sum */
rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[VARYING_SLOT_COL1][0];
gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[VARYING_SLOT_COL1][1];
bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[VARYING_SLOT_COL1][2];
UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
/* draw */
SWRAST_CONTEXT(ctx)->SpecPoint(ctx, ncv0);
/* restore */
COPY_CHAN4(ncv0->color, cSave);
}
/**
* Examine current state to determine which point drawing function to use.
*/
void
_swrast_choose_point(struct gl_context *ctx)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
const GLfloat size = CLAMP(ctx->Point.Size,
ctx->Point.MinSize,
ctx->Point.MaxSize);
if (ctx->RenderMode == GL_RENDER) {
if (ctx->Point.PointSprite) {
swrast->Point = sprite_point;
}
else if (ctx->Point.SmoothFlag) {
swrast->Point = smooth_point;
}
else if (size > 1.0F ||
ctx->Point._Attenuated ||
ctx->VertexProgram.PointSizeEnabled) {
swrast->Point = large_point;
}
else {
swrast->Point = pixel_point;
}
}
else if (ctx->RenderMode == GL_FEEDBACK) {
swrast->Point = _swrast_feedback_point;
}
else {
/* GL_SELECT mode */
swrast->Point = _swrast_select_point;
}
}