/**
* 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[FRAG_ATTRIB_WPOS][3] = 1.0F;
span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
/* check if we need to flush */
if (span->end >= 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[FRAG_ATTRIB_WPOS][0];
span->array->y[count] = (GLint) vert->attrib[FRAG_ATTRIB_WPOS][1];
span->array->z[count] = (GLint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
span->end = count + 1;
ASSERT(span->end <= MAX_WIDTH);
}
/**
* Draw a point sprite
*/
static void
sprite_point(GLcontext *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[FRAG_ATTRIB_WPOS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][3] = 1.0F;
span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
{
GLfloat s, r, dsdx;
/* texcoord / pointcoord interpolants */
s = 0.0;
dsdx = 1.0 / size;
if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) {
dtdy = 1.0 / size;
t0 = 0.5 * dtdy;
}
else {
/* GL_UPPER_LEFT */
dtdy = -1.0 / size;
t0 = 1.0 + 0.5 * dtdy;
}
ATTRIB_LOOP_BEGIN
if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) {
const GLuint u = attr - FRAG_ATTRIB_TEX0;
/* a texcoord */
if (ctx->Point.CoordReplace[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 == FRAG_ATTRIB_FOGC) {
/* GLSL gl_PointCoord is stored in fog.zw */
span.attrStart[FRAG_ATTRIB_FOGC][2] = 0.0;
span.attrStart[FRAG_ATTRIB_FOGC][3] = 0.0; /* t0 set below */
span.attrStepX[FRAG_ATTRIB_FOGC][2] = dsdx;
span.attrStepX[FRAG_ATTRIB_FOGC][3] = 0.0;
span.attrStepY[FRAG_ATTRIB_FOGC][2] = 0.0;
span.attrStepY[FRAG_ATTRIB_FOGC][3] = dtdy;
tCoords[numTcoords++] = FRAG_ATTRIB_FOGC;
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[FRAG_ATTRIB_WPOS][0];
const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][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 + 0.501) - iRadius;
xmax = xmin + iSize - 1;
ymin = (GLint) (y + 0.501) - 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++) {
if (tCoords[i] == FRAG_ATTRIB_FOGC)
span.attrStart[FRAG_ATTRIB_FOGC][3] = tcoord;
else
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 large (size >= 1) non-AA point. RGB or CI mode.
*/
static void
large_point(GLcontext *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
const GLboolean ciMode = !ctx->Visual.rgbMode;
SWspan span;
GLfloat size;
CULL_INVALID(vert);
/* z coord */
if (ctx->DrawBuffer->Visual.depthBits <= 16)
span.z = FloatToFixed(vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][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;
if (ciMode) {
span.interpMask = SPAN_Z | SPAN_INDEX;
span.index = FloatToFixed(vert->attrib[FRAG_ATTRIB_CI][0]);
span.indexStep = 0;
}
else {
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[FRAG_ATTRIB_WPOS][3] = 1.0F;
span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
span.attrStepY[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][0];
const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][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 + 0.501) - iRadius;
xmax = xmin + iSize - 1;
ymin = (GLint) (y + 0.501) - 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 <= MAX_WIDTH);
_swrast_write_rgba_span(ctx, &span);
}
}
/**
* Draw smooth/antialiased point. RGB or CI mode.
*/
static void
smooth_point(GLcontext *ctx, const SWvertex *vert)
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
const GLboolean ciMode = !ctx->Visual.rgbMode;
SWspan span;
GLfloat size, alphaAtten;
CULL_INVALID(vert);
/* z coord */
if (ctx->DrawBuffer->Visual.depthBits <= 16)
span.z = FloatToFixed(vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
else
span.z = (GLuint) (vert->attrib[FRAG_ATTRIB_WPOS][2] + 0.5F);
span.zStep = 0;
size = get_size(ctx, vert, GL_TRUE);
/* alpha attenuation / fade factor */
if (ctx->Multisample._Enabled) {
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[FRAG_ATTRIB_WPOS][3] = 1.0F;
span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
span.attrStepY[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][0];
const GLfloat y = vert->attrib[FRAG_ATTRIB_WPOS][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;
if (ciMode) {
/* coverage in [0,15] */
coverage *= 15.0;
}
}
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);
}
}
}