/*
* 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 "c99_math.h"
#include "main/glheader.h"
#include "main/feedback.h"
#include "main/light.h"
#include "main/macros.h"
#include "util/simple_list.h"
#include "main/mtypes.h"
#include "main/viewport.h"
#include "math/m_matrix.h"
#include "tnl/tnl.h"
/**
* Clip a point against the view volume.
*
* \param v vertex vector describing the point to clip.
*
* \return zero if outside view volume, or one if inside.
*/
static GLuint
viewclip_point_xy( const GLfloat v[] )
{
if ( v[0] > v[3] || v[0] < -v[3]
|| v[1] > v[3] || v[1] < -v[3] ) {
return 0;
}
else {
return 1;
}
}
/**
* Clip a point against the far/near Z clipping planes.
*
* \param v vertex vector describing the point to clip.
*
* \return zero if outside view volume, or one if inside.
*/
static GLuint
viewclip_point_z( const GLfloat v[] )
{
if (v[2] > v[3] || v[2] < -v[3] ) {
return 0;
}
else {
return 1;
}
}
/**
* Clip a point against the user clipping planes.
*
* \param ctx GL context.
* \param v vertex vector describing the point to clip.
*
* \return zero if the point was clipped, or one otherwise.
*/
static GLuint
userclip_point( struct gl_context *ctx, const GLfloat v[] )
{
GLuint p;
for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
+ v[1] * ctx->Transform._ClipUserPlane[p][1]
+ v[2] * ctx->Transform._ClipUserPlane[p][2]
+ v[3] * ctx->Transform._ClipUserPlane[p][3];
if (dot < 0.0F) {
return 0;
}
}
}
return 1;
}
/**
* Compute lighting for the raster position. RGB modes computed.
* \param ctx the context
* \param vertex vertex location
* \param normal normal vector
* \param Rcolor returned color
* \param Rspec returned specular color (if separate specular enabled)
*/
static void
shade_rastpos(struct gl_context *ctx,
const GLfloat vertex[4],
const GLfloat normal[3],
GLfloat Rcolor[4],
GLfloat Rspec[4])
{
/*const*/ GLfloat (*base)[3] = ctx->Light._BaseColor;
const struct gl_light *light;
GLfloat diffuseColor[4], specularColor[4]; /* for RGB mode only */
COPY_3V(diffuseColor, base[0]);
diffuseColor[3] = CLAMP(
ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3], 0.0F, 1.0F );
ASSIGN_4V(specularColor, 0.0, 0.0, 0.0, 1.0);
foreach (light, &ctx->Light.EnabledList) {
GLfloat attenuation = 1.0;
GLfloat VP[3]; /* vector from vertex to light pos */
GLfloat n_dot_VP;
GLfloat diffuseContrib[3], specularContrib[3];
if (!(light->_Flags & LIGHT_POSITIONAL)) {
/* light at infinity */
COPY_3V(VP, light->_VP_inf_norm);
attenuation = light->_VP_inf_spot_attenuation;
}
else {
/* local/positional light */
GLfloat d;
/* VP = vector from vertex pos to light[i].pos */
SUB_3V(VP, light->_Position, vertex);
/* d = length(VP) */
d = (GLfloat) LEN_3FV( VP );
if (d > 1.0e-6) {
/* normalize VP */
GLfloat invd = 1.0F / d;
SELF_SCALE_SCALAR_3V(VP, invd);
}
/* atti */
attenuation = 1.0F / (light->ConstantAttenuation + d *
(light->LinearAttenuation + d *
light->QuadraticAttenuation));
if (light->_Flags & LIGHT_SPOT) {
GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
if (PV_dot_dir<light->_CosCutoff) {
continue;
}
else {
GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
attenuation *= spot;
}
}
}
if (attenuation < 1e-3)
continue;
n_dot_VP = DOT3( normal, VP );
if (n_dot_VP < 0.0F) {
ACC_SCALE_SCALAR_3V(diffuseColor, attenuation, light->_MatAmbient[0]);
continue;
}
/* Ambient + diffuse */
COPY_3V(diffuseContrib, light->_MatAmbient[0]);
ACC_SCALE_SCALAR_3V(diffuseContrib, n_dot_VP, light->_MatDiffuse[0]);
/* Specular */
{
const GLfloat *h;
GLfloat n_dot_h;
ASSIGN_3V(specularContrib, 0.0, 0.0, 0.0);
if (ctx->Light.Model.LocalViewer) {
GLfloat v[3];
COPY_3V(v, vertex);
NORMALIZE_3FV(v);
SUB_3V(VP, VP, v);
NORMALIZE_3FV(VP);
h = VP;
}
else if (light->_Flags & LIGHT_POSITIONAL) {
ACC_3V(VP, ctx->_EyeZDir);
NORMALIZE_3FV(VP);
h = VP;
}
else {
h = light->_h_inf_norm;
}
n_dot_h = DOT3(normal, h);
if (n_dot_h > 0.0F) {
GLfloat shine;
GLfloat spec_coef;
shine = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
spec_coef = powf(n_dot_h, shine);
if (spec_coef > 1.0e-10) {
if (ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR) {
ACC_SCALE_SCALAR_3V( specularContrib, spec_coef,
light->_MatSpecular[0]);
}
else {
ACC_SCALE_SCALAR_3V( diffuseContrib, spec_coef,
light->_MatSpecular[0]);
}
}
}
}
ACC_SCALE_SCALAR_3V( diffuseColor, attenuation, diffuseContrib );
ACC_SCALE_SCALAR_3V( specularColor, attenuation, specularContrib );
}
Rcolor[0] = CLAMP(diffuseColor[0], 0.0F, 1.0F);
Rcolor[1] = CLAMP(diffuseColor[1], 0.0F, 1.0F);
Rcolor[2] = CLAMP(diffuseColor[2], 0.0F, 1.0F);
Rcolor[3] = CLAMP(diffuseColor[3], 0.0F, 1.0F);
Rspec[0] = CLAMP(specularColor[0], 0.0F, 1.0F);
Rspec[1] = CLAMP(specularColor[1], 0.0F, 1.0F);
Rspec[2] = CLAMP(specularColor[2], 0.0F, 1.0F);
Rspec[3] = CLAMP(specularColor[3], 0.0F, 1.0F);
}
/**
* Do texgen needed for glRasterPos.
* \param ctx rendering context
* \param vObj object-space vertex coordinate
* \param vEye eye-space vertex coordinate
* \param normal vertex normal
* \param unit texture unit number
* \param texcoord incoming texcoord and resulting texcoord
*/
static void
compute_texgen(struct gl_context *ctx, const GLfloat vObj[4], const GLfloat vEye[4],
const GLfloat normal[3], GLuint unit, GLfloat texcoord[4])
{
const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
/* always compute sphere map terms, just in case */
GLfloat u[3], two_nu, rx, ry, rz, m, mInv;
COPY_3V(u, vEye);
NORMALIZE_3FV(u);
two_nu = 2.0F * DOT3(normal, u);
rx = u[0] - normal[0] * two_nu;
ry = u[1] - normal[1] * two_nu;
rz = u[2] - normal[2] * two_nu;
m = rx * rx + ry * ry + (rz + 1.0F) * (rz + 1.0F);
if (m > 0.0F)
mInv = 0.5F * (1.0f / sqrtf(m));
else
mInv = 0.0F;
if (texUnit->TexGenEnabled & S_BIT) {
switch (texUnit->GenS.Mode) {
case GL_OBJECT_LINEAR:
texcoord[0] = DOT4(vObj, texUnit->GenS.ObjectPlane);
break;
case GL_EYE_LINEAR:
texcoord[0] = DOT4(vEye, texUnit->GenS.EyePlane);
break;
case GL_SPHERE_MAP:
texcoord[0] = rx * mInv + 0.5F;
break;
case GL_REFLECTION_MAP:
texcoord[0] = rx;
break;
case GL_NORMAL_MAP:
texcoord[0] = normal[0];
break;
default:
_mesa_problem(ctx, "Bad S texgen in compute_texgen()");
return;
}
}
if (texUnit->TexGenEnabled & T_BIT) {
switch (texUnit->GenT.Mode) {
case GL_OBJECT_LINEAR:
texcoord[1] = DOT4(vObj, texUnit->GenT.ObjectPlane);
break;
case GL_EYE_LINEAR:
texcoord[1] = DOT4(vEye, texUnit->GenT.EyePlane);
break;
case GL_SPHERE_MAP:
texcoord[1] = ry * mInv + 0.5F;
break;
case GL_REFLECTION_MAP:
texcoord[1] = ry;
break;
case GL_NORMAL_MAP:
texcoord[1] = normal[1];
break;
default:
_mesa_problem(ctx, "Bad T texgen in compute_texgen()");
return;
}
}
if (texUnit->TexGenEnabled & R_BIT) {
switch (texUnit->GenR.Mode) {
case GL_OBJECT_LINEAR:
texcoord[2] = DOT4(vObj, texUnit->GenR.ObjectPlane);
break;
case GL_EYE_LINEAR:
texcoord[2] = DOT4(vEye, texUnit->GenR.EyePlane);
break;
case GL_REFLECTION_MAP:
texcoord[2] = rz;
break;
case GL_NORMAL_MAP:
texcoord[2] = normal[2];
break;
default:
_mesa_problem(ctx, "Bad R texgen in compute_texgen()");
return;
}
}
if (texUnit->TexGenEnabled & Q_BIT) {
switch (texUnit->GenQ.Mode) {
case GL_OBJECT_LINEAR:
texcoord[3] = DOT4(vObj, texUnit->GenQ.ObjectPlane);
break;
case GL_EYE_LINEAR:
texcoord[3] = DOT4(vEye, texUnit->GenQ.EyePlane);
break;
default:
_mesa_problem(ctx, "Bad Q texgen in compute_texgen()");
return;
}
}
}
/**
* glRasterPos transformation. Typically called via ctx->Driver.RasterPos().
* XXX some of this code (such as viewport xform, clip testing and setting
* of ctx->Current.Raster* fields) could get lifted up into the
* main/rasterpos.c code.
*
* \param vObj vertex position in object space
*/
void
_tnl_RasterPos(struct gl_context *ctx, const GLfloat vObj[4])
{
if (ctx->VertexProgram._Enabled) {
/* XXX implement this */
_mesa_problem(ctx, "Vertex programs not implemented for glRasterPos");
return;
}
else {
GLfloat eye[4], clip[4], ndc[3], d;
GLfloat *norm, eyenorm[3];
GLfloat *objnorm = ctx->Current.Attrib[VERT_ATTRIB_NORMAL];
double scale[3], translate[3];
/* apply modelview matrix: eye = MV * obj */
TRANSFORM_POINT( eye, ctx->ModelviewMatrixStack.Top->m, vObj );
/* apply projection matrix: clip = Proj * eye */
TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
/* clip to view volume. */
if (!ctx->Transform.DepthClamp) {
if (viewclip_point_z(clip) == 0) {
ctx->Current.RasterPosValid = GL_FALSE;
return;
}
}
if (!ctx->Transform.RasterPositionUnclipped) {
if (viewclip_point_xy(clip) == 0) {
ctx->Current.RasterPosValid = GL_FALSE;
return;
}
}
/* clip to user clipping planes */
if (ctx->Transform.ClipPlanesEnabled && !userclip_point(ctx, clip)) {
ctx->Current.RasterPosValid = GL_FALSE;
return;
}
/* ndc = clip / W */
d = (clip[3] == 0.0F) ? 1.0F : 1.0F / clip[3];
ndc[0] = clip[0] * d;
ndc[1] = clip[1] * d;
ndc[2] = clip[2] * d;
/* wincoord = viewport_mapping(ndc) */
_mesa_get_viewport_xform(ctx, 0, scale, translate);
ctx->Current.RasterPos[0] = ndc[0] * scale[0] + translate[0];
ctx->Current.RasterPos[1] = ndc[1] * scale[1] + translate[1];
ctx->Current.RasterPos[2] = ndc[2] * scale[2] + translate[2];
ctx->Current.RasterPos[3] = clip[3];
if (ctx->Transform.DepthClamp) {
ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
ctx->ViewportArray[0].Near,
ctx->ViewportArray[0].Far);
}
/* compute raster distance */
if (ctx->Fog.FogCoordinateSource == GL_FOG_COORDINATE_EXT)
ctx->Current.RasterDistance = ctx->Current.Attrib[VERT_ATTRIB_FOG][0];
else
ctx->Current.RasterDistance =
sqrtf( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
/* compute transformed normal vector (for lighting or texgen) */
if (ctx->_NeedEyeCoords) {
const GLfloat *inv = ctx->ModelviewMatrixStack.Top->inv;
TRANSFORM_NORMAL( eyenorm, objnorm, inv );
norm = eyenorm;
}
else {
norm = objnorm;
}
/* update raster color */
if (ctx->Light.Enabled) {
/* lighting */
shade_rastpos( ctx, vObj, norm,
ctx->Current.RasterColor,
ctx->Current.RasterSecondaryColor );
}
else {
/* use current color */
COPY_4FV(ctx->Current.RasterColor,
ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
COPY_4FV(ctx->Current.RasterSecondaryColor,
ctx->Current.Attrib[VERT_ATTRIB_COLOR1]);
}
/* texture coords */
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
GLfloat tc[4];
COPY_4V(tc, ctx->Current.Attrib[VERT_ATTRIB_TEX0 + u]);
if (ctx->Texture.Unit[u].TexGenEnabled) {
compute_texgen(ctx, vObj, eye, norm, u, tc);
}
TRANSFORM_POINT(ctx->Current.RasterTexCoords[u],
ctx->TextureMatrixStack[u].Top->m, tc);
}
}
ctx->Current.RasterPosValid = GL_TRUE;
}
if (ctx->RenderMode == GL_SELECT) {
_mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
}
}