0,0 → 1,492 |
/* |
* Mesa 3-D graphics library |
* Version: 6.5.3 |
* |
* 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. |
*/ |
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#include "main/glheader.h" |
#include "main/imports.h" |
#include "main/macros.h" |
#include "main/mtypes.h" |
#include "swrast/s_aaline.h" |
#include "swrast/s_context.h" |
#include "swrast/s_span.h" |
#include "swrast/swrast.h" |
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#define SUB_PIXEL 4 |
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/* |
* Info about the AA line we're rendering |
*/ |
struct LineInfo |
{ |
GLfloat x0, y0; /* start */ |
GLfloat x1, y1; /* end */ |
GLfloat dx, dy; /* direction vector */ |
GLfloat len; /* length */ |
GLfloat halfWidth; /* half of line width */ |
GLfloat xAdj, yAdj; /* X and Y adjustment for quad corners around line */ |
/* for coverage computation */ |
GLfloat qx0, qy0; /* quad vertices */ |
GLfloat qx1, qy1; |
GLfloat qx2, qy2; |
GLfloat qx3, qy3; |
GLfloat ex0, ey0; /* quad edge vectors */ |
GLfloat ex1, ey1; |
GLfloat ex2, ey2; |
GLfloat ex3, ey3; |
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/* DO_Z */ |
GLfloat zPlane[4]; |
/* DO_RGBA - always enabled */ |
GLfloat rPlane[4], gPlane[4], bPlane[4], aPlane[4]; |
/* DO_ATTRIBS */ |
GLfloat wPlane[4]; |
GLfloat attrPlane[FRAG_ATTRIB_MAX][4][4]; |
GLfloat lambda[FRAG_ATTRIB_MAX]; |
GLfloat texWidth[FRAG_ATTRIB_MAX]; |
GLfloat texHeight[FRAG_ATTRIB_MAX]; |
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SWspan span; |
}; |
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/* |
* Compute the equation of a plane used to interpolate line fragment data |
* such as color, Z, texture coords, etc. |
* Input: (x0, y0) and (x1,y1) are the endpoints of the line. |
* z0, and z1 are the end point values to interpolate. |
* Output: plane - the plane equation. |
* |
* Note: we don't really have enough parameters to specify a plane. |
* We take the endpoints of the line and compute a plane such that |
* the cross product of the line vector and the plane normal is |
* parallel to the projection plane. |
*/ |
static void |
compute_plane(GLfloat x0, GLfloat y0, GLfloat x1, GLfloat y1, |
GLfloat z0, GLfloat z1, GLfloat plane[4]) |
{ |
#if 0 |
/* original */ |
const GLfloat px = x1 - x0; |
const GLfloat py = y1 - y0; |
const GLfloat pz = z1 - z0; |
const GLfloat qx = -py; |
const GLfloat qy = px; |
const GLfloat qz = 0; |
const GLfloat a = py * qz - pz * qy; |
const GLfloat b = pz * qx - px * qz; |
const GLfloat c = px * qy - py * qx; |
const GLfloat d = -(a * x0 + b * y0 + c * z0); |
plane[0] = a; |
plane[1] = b; |
plane[2] = c; |
plane[3] = d; |
#else |
/* simplified */ |
const GLfloat px = x1 - x0; |
const GLfloat py = y1 - y0; |
const GLfloat pz = z0 - z1; |
const GLfloat a = pz * px; |
const GLfloat b = pz * py; |
const GLfloat c = px * px + py * py; |
const GLfloat d = -(a * x0 + b * y0 + c * z0); |
if (a == 0.0 && b == 0.0 && c == 0.0 && d == 0.0) { |
plane[0] = 0.0; |
plane[1] = 0.0; |
plane[2] = 1.0; |
plane[3] = 0.0; |
} |
else { |
plane[0] = a; |
plane[1] = b; |
plane[2] = c; |
plane[3] = d; |
} |
#endif |
} |
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static INLINE void |
constant_plane(GLfloat value, GLfloat plane[4]) |
{ |
plane[0] = 0.0; |
plane[1] = 0.0; |
plane[2] = -1.0; |
plane[3] = value; |
} |
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static INLINE GLfloat |
solve_plane(GLfloat x, GLfloat y, const GLfloat plane[4]) |
{ |
const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2]; |
return z; |
} |
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#define SOLVE_PLANE(X, Y, PLANE) \ |
((PLANE[3] + PLANE[0] * (X) + PLANE[1] * (Y)) / -PLANE[2]) |
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/* |
* Return 1 / solve_plane(). |
*/ |
static INLINE GLfloat |
solve_plane_recip(GLfloat x, GLfloat y, const GLfloat plane[4]) |
{ |
const GLfloat denom = plane[3] + plane[0] * x + plane[1] * y; |
if (denom == 0.0) |
return 0.0; |
else |
return -plane[2] / denom; |
} |
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/* |
* Solve plane and return clamped GLchan value. |
*/ |
static INLINE GLchan |
solve_plane_chan(GLfloat x, GLfloat y, const GLfloat plane[4]) |
{ |
const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2]; |
#if CHAN_TYPE == GL_FLOAT |
return CLAMP(z, 0.0F, CHAN_MAXF); |
#else |
if (z < 0) |
return 0; |
else if (z > CHAN_MAX) |
return CHAN_MAX; |
return (GLchan) IROUND_POS(z); |
#endif |
} |
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/* |
* Compute mipmap level of detail. |
*/ |
static INLINE GLfloat |
compute_lambda(const GLfloat sPlane[4], const GLfloat tPlane[4], |
GLfloat invQ, GLfloat width, GLfloat height) |
{ |
GLfloat dudx = sPlane[0] / sPlane[2] * invQ * width; |
GLfloat dudy = sPlane[1] / sPlane[2] * invQ * width; |
GLfloat dvdx = tPlane[0] / tPlane[2] * invQ * height; |
GLfloat dvdy = tPlane[1] / tPlane[2] * invQ * height; |
GLfloat r1 = dudx * dudx + dudy * dudy; |
GLfloat r2 = dvdx * dvdx + dvdy * dvdy; |
GLfloat rho2 = r1 + r2; |
/* return log base 2 of rho */ |
if (rho2 == 0.0F) |
return 0.0; |
else |
return (GLfloat) (LOGF(rho2) * 1.442695 * 0.5);/* 1.442695 = 1/log(2) */ |
} |
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/* |
* Fill in the samples[] array with the (x,y) subpixel positions of |
* xSamples * ySamples sample positions. |
* Note that the four corner samples are put into the first four |
* positions of the array. This allows us to optimize for the common |
* case of all samples being inside the polygon. |
*/ |
static void |
make_sample_table(GLint xSamples, GLint ySamples, GLfloat samples[][2]) |
{ |
const GLfloat dx = 1.0F / (GLfloat) xSamples; |
const GLfloat dy = 1.0F / (GLfloat) ySamples; |
GLint x, y; |
GLint i; |
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i = 4; |
for (x = 0; x < xSamples; x++) { |
for (y = 0; y < ySamples; y++) { |
GLint j; |
if (x == 0 && y == 0) { |
/* lower left */ |
j = 0; |
} |
else if (x == xSamples - 1 && y == 0) { |
/* lower right */ |
j = 1; |
} |
else if (x == 0 && y == ySamples - 1) { |
/* upper left */ |
j = 2; |
} |
else if (x == xSamples - 1 && y == ySamples - 1) { |
/* upper right */ |
j = 3; |
} |
else { |
j = i++; |
} |
samples[j][0] = x * dx + 0.5F * dx; |
samples[j][1] = y * dy + 0.5F * dy; |
} |
} |
} |
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/* |
* Compute how much of the given pixel's area is inside the rectangle |
* defined by vertices v0, v1, v2, v3. |
* Vertices MUST be specified in counter-clockwise order. |
* Return: coverage in [0, 1]. |
*/ |
static GLfloat |
compute_coveragef(const struct LineInfo *info, |
GLint winx, GLint winy) |
{ |
static GLfloat samples[SUB_PIXEL * SUB_PIXEL][2]; |
static GLboolean haveSamples = GL_FALSE; |
const GLfloat x = (GLfloat) winx; |
const GLfloat y = (GLfloat) winy; |
GLint stop = 4, i; |
GLfloat insideCount = SUB_PIXEL * SUB_PIXEL; |
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if (!haveSamples) { |
make_sample_table(SUB_PIXEL, SUB_PIXEL, samples); |
haveSamples = GL_TRUE; |
} |
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#if 0 /*DEBUG*/ |
{ |
const GLfloat area = dx0 * dy1 - dx1 * dy0; |
assert(area >= 0.0); |
} |
#endif |
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for (i = 0; i < stop; i++) { |
const GLfloat sx = x + samples[i][0]; |
const GLfloat sy = y + samples[i][1]; |
const GLfloat fx0 = sx - info->qx0; |
const GLfloat fy0 = sy - info->qy0; |
const GLfloat fx1 = sx - info->qx1; |
const GLfloat fy1 = sy - info->qy1; |
const GLfloat fx2 = sx - info->qx2; |
const GLfloat fy2 = sy - info->qy2; |
const GLfloat fx3 = sx - info->qx3; |
const GLfloat fy3 = sy - info->qy3; |
/* cross product determines if sample is inside or outside each edge */ |
GLfloat cross0 = (info->ex0 * fy0 - info->ey0 * fx0); |
GLfloat cross1 = (info->ex1 * fy1 - info->ey1 * fx1); |
GLfloat cross2 = (info->ex2 * fy2 - info->ey2 * fx2); |
GLfloat cross3 = (info->ex3 * fy3 - info->ey3 * fx3); |
/* Check if the sample is exactly on an edge. If so, let cross be a |
* positive or negative value depending on the direction of the edge. |
*/ |
if (cross0 == 0.0F) |
cross0 = info->ex0 + info->ey0; |
if (cross1 == 0.0F) |
cross1 = info->ex1 + info->ey1; |
if (cross2 == 0.0F) |
cross2 = info->ex2 + info->ey2; |
if (cross3 == 0.0F) |
cross3 = info->ex3 + info->ey3; |
if (cross0 < 0.0F || cross1 < 0.0F || cross2 < 0.0F || cross3 < 0.0F) { |
/* point is outside quadrilateral */ |
insideCount -= 1.0F; |
stop = SUB_PIXEL * SUB_PIXEL; |
} |
} |
if (stop == 4) |
return 1.0F; |
else |
return insideCount * (1.0F / (SUB_PIXEL * SUB_PIXEL)); |
} |
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typedef void (*plot_func)(struct gl_context *ctx, struct LineInfo *line, |
int ix, int iy); |
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/* |
* Draw an AA line segment (called many times per line when stippling) |
*/ |
static void |
segment(struct gl_context *ctx, |
struct LineInfo *line, |
plot_func plot, |
GLfloat t0, GLfloat t1) |
{ |
const GLfloat absDx = (line->dx < 0.0F) ? -line->dx : line->dx; |
const GLfloat absDy = (line->dy < 0.0F) ? -line->dy : line->dy; |
/* compute the actual segment's endpoints */ |
const GLfloat x0 = line->x0 + t0 * line->dx; |
const GLfloat y0 = line->y0 + t0 * line->dy; |
const GLfloat x1 = line->x0 + t1 * line->dx; |
const GLfloat y1 = line->y0 + t1 * line->dy; |
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/* compute vertices of the line-aligned quadrilateral */ |
line->qx0 = x0 - line->yAdj; |
line->qy0 = y0 + line->xAdj; |
line->qx1 = x0 + line->yAdj; |
line->qy1 = y0 - line->xAdj; |
line->qx2 = x1 + line->yAdj; |
line->qy2 = y1 - line->xAdj; |
line->qx3 = x1 - line->yAdj; |
line->qy3 = y1 + line->xAdj; |
/* compute the quad's edge vectors (for coverage calc) */ |
line->ex0 = line->qx1 - line->qx0; |
line->ey0 = line->qy1 - line->qy0; |
line->ex1 = line->qx2 - line->qx1; |
line->ey1 = line->qy2 - line->qy1; |
line->ex2 = line->qx3 - line->qx2; |
line->ey2 = line->qy3 - line->qy2; |
line->ex3 = line->qx0 - line->qx3; |
line->ey3 = line->qy0 - line->qy3; |
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if (absDx > absDy) { |
/* X-major line */ |
GLfloat dydx = line->dy / line->dx; |
GLfloat xLeft, xRight, yBot, yTop; |
GLint ix, ixRight; |
if (x0 < x1) { |
xLeft = x0 - line->halfWidth; |
xRight = x1 + line->halfWidth; |
if (line->dy >= 0.0) { |
yBot = y0 - 3.0F * line->halfWidth; |
yTop = y0 + line->halfWidth; |
} |
else { |
yBot = y0 - line->halfWidth; |
yTop = y0 + 3.0F * line->halfWidth; |
} |
} |
else { |
xLeft = x1 - line->halfWidth; |
xRight = x0 + line->halfWidth; |
if (line->dy <= 0.0) { |
yBot = y1 - 3.0F * line->halfWidth; |
yTop = y1 + line->halfWidth; |
} |
else { |
yBot = y1 - line->halfWidth; |
yTop = y1 + 3.0F * line->halfWidth; |
} |
} |
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/* scan along the line, left-to-right */ |
ixRight = (GLint) (xRight + 1.0F); |
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/*printf("avg span height: %g\n", yTop - yBot);*/ |
for (ix = (GLint) xLeft; ix < ixRight; ix++) { |
const GLint iyBot = (GLint) yBot; |
const GLint iyTop = (GLint) (yTop + 1.0F); |
GLint iy; |
/* scan across the line, bottom-to-top */ |
for (iy = iyBot; iy < iyTop; iy++) { |
(*plot)(ctx, line, ix, iy); |
} |
yBot += dydx; |
yTop += dydx; |
} |
} |
else { |
/* Y-major line */ |
GLfloat dxdy = line->dx / line->dy; |
GLfloat yBot, yTop, xLeft, xRight; |
GLint iy, iyTop; |
if (y0 < y1) { |
yBot = y0 - line->halfWidth; |
yTop = y1 + line->halfWidth; |
if (line->dx >= 0.0) { |
xLeft = x0 - 3.0F * line->halfWidth; |
xRight = x0 + line->halfWidth; |
} |
else { |
xLeft = x0 - line->halfWidth; |
xRight = x0 + 3.0F * line->halfWidth; |
} |
} |
else { |
yBot = y1 - line->halfWidth; |
yTop = y0 + line->halfWidth; |
if (line->dx <= 0.0) { |
xLeft = x1 - 3.0F * line->halfWidth; |
xRight = x1 + line->halfWidth; |
} |
else { |
xLeft = x1 - line->halfWidth; |
xRight = x1 + 3.0F * line->halfWidth; |
} |
} |
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/* scan along the line, bottom-to-top */ |
iyTop = (GLint) (yTop + 1.0F); |
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/*printf("avg span width: %g\n", xRight - xLeft);*/ |
for (iy = (GLint) yBot; iy < iyTop; iy++) { |
const GLint ixLeft = (GLint) xLeft; |
const GLint ixRight = (GLint) (xRight + 1.0F); |
GLint ix; |
/* scan across the line, left-to-right */ |
for (ix = ixLeft; ix < ixRight; ix++) { |
(*plot)(ctx, line, ix, iy); |
} |
xLeft += dxdy; |
xRight += dxdy; |
} |
} |
} |
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#define NAME(x) aa_rgba_##x |
#define DO_Z |
#include "s_aalinetemp.h" |
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#define NAME(x) aa_general_rgba_##x |
#define DO_Z |
#define DO_ATTRIBS |
#include "s_aalinetemp.h" |
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void |
_swrast_choose_aa_line_function(struct gl_context *ctx) |
{ |
SWcontext *swrast = SWRAST_CONTEXT(ctx); |
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ASSERT(ctx->Line.SmoothFlag); |
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if (ctx->Texture._EnabledCoordUnits != 0 |
|| ctx->FragmentProgram._Current |
|| (ctx->Light.Enabled && |
ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR) |
|| ctx->Fog.ColorSumEnabled |
|| swrast->_FogEnabled) { |
swrast->Line = aa_general_rgba_line; |
} |
else { |
swrast->Line = aa_rgba_line; |
} |
} |