1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/graphics/m3g/m3gcore11/src/m3g_fog.c Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,422 @@
1.4 +/*
1.5 +* Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies).
1.6 +* All rights reserved.
1.7 +* This component and the accompanying materials are made available
1.8 +* under the terms of the License "Eclipse Public License v1.0"
1.9 +* which accompanies this distribution, and is available
1.10 +* at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.11 +*
1.12 +* Initial Contributors:
1.13 +* Nokia Corporation - initial contribution.
1.14 +*
1.15 +* Contributors:
1.16 +*
1.17 +* Description: Fog implementation
1.18 +*
1.19 +*/
1.20 +
1.21 +
1.22 +/*!
1.23 + * \internal
1.24 + * \file
1.25 + * \brief Fog implementation
1.26 + */
1.27 +
1.28 +#ifndef M3G_CORE_INCLUDE
1.29 +# error included by m3g_core.c; do not compile separately.
1.30 +#endif
1.31 +
1.32 +#include "m3g_fog.h"
1.33 +#include "m3g_animationtrack.h"
1.34 +
1.35 +/*----------------------------------------------------------------------
1.36 + * Internal functions
1.37 + *--------------------------------------------------------------------*/
1.38 +
1.39 +/*!
1.40 + * \internal
1.41 + * \brief Destroys this Fog object.
1.42 + *
1.43 + * \param obj Fog object
1.44 + */
1.45 +static void m3gDestroyFog(Object *obj)
1.46 +{
1.47 + Fog *fog = (Fog *) obj;
1.48 + M3G_VALIDATE_OBJECT(fog);
1.49 +
1.50 + m3gDestroyObject(&fog->object);
1.51 +}
1.52 +
1.53 +/*!
1.54 + * \internal
1.55 + * \brief Overloaded Object3D method.
1.56 + *
1.57 + * \param property animation property
1.58 + * \retval M3G_TRUE property supported
1.59 + * \retval M3G_FALSE property not supported
1.60 + */
1.61 +static M3Gbool m3gFogIsCompatible(M3Gint property)
1.62 +{
1.63 + switch (property) {
1.64 + case M3G_ANIM_COLOR:
1.65 + case M3G_ANIM_DENSITY:
1.66 + case M3G_ANIM_FAR_DISTANCE:
1.67 + case M3G_ANIM_NEAR_DISTANCE:
1.68 + return M3G_TRUE;
1.69 + default:
1.70 + return m3gObjectIsCompatible(property);
1.71 + }
1.72 +}
1.73 +
1.74 +/*!
1.75 + * \internal
1.76 + * \brief Overloaded Object3D method.
1.77 + *
1.78 + * \param self Fog object
1.79 + * \param property animation property
1.80 + * \param valueSize size of value array
1.81 + * \param value value array
1.82 + */
1.83 +static void m3gFogUpdateProperty(Object *self,
1.84 + M3Gint property,
1.85 + M3Gint valueSize,
1.86 + const M3Gfloat *value)
1.87 +{
1.88 + Fog *fog = (Fog *)self;
1.89 + M3G_VALIDATE_OBJECT(fog);
1.90 + M3G_ASSERT_PTR(value);
1.91 +
1.92 + switch (property) {
1.93 + case M3G_ANIM_COLOR:
1.94 + M3G_ASSERT(valueSize >= 3);
1.95 + fog->color = m3gColor3f(value[0], value[1], value[2]) & M3G_RGB_MASK;
1.96 + break;
1.97 + case M3G_ANIM_DENSITY:
1.98 + M3G_ASSERT(valueSize >= 1);
1.99 + fog->density = (value[0] < 0.f) ? 0.f : value[0];
1.100 + break;
1.101 + case M3G_ANIM_FAR_DISTANCE:
1.102 + M3G_ASSERT(valueSize >= 1);
1.103 + fog->end = value[0];
1.104 + break;
1.105 + case M3G_ANIM_NEAR_DISTANCE:
1.106 + M3G_ASSERT(valueSize >= 1);
1.107 + fog->start = value[0];
1.108 + break;
1.109 + default:
1.110 + m3gObjectUpdateProperty(self, property, valueSize, value);
1.111 + }
1.112 +}
1.113 +
1.114 +/*!
1.115 + * \internal
1.116 + * \brief Overloaded Object3D method.
1.117 + *
1.118 + * \param originalObj original Fog object
1.119 + * \param cloneObj pointer to cloned Fog object
1.120 + * \param pairs array for all object-duplicate pairs
1.121 + * \param numPairs number of pairs
1.122 + */
1.123 +static M3Gbool m3gFogDuplicate(const Object *originalObj,
1.124 + Object **cloneObj,
1.125 + Object **pairs,
1.126 + M3Gint *numPairs)
1.127 +{
1.128 + Fog *original = (Fog *)originalObj;
1.129 + Fog *clone = (Fog *)m3gCreateFog(originalObj->interface);
1.130 + *cloneObj = (Object *)clone;
1.131 + if (*cloneObj == NULL) {
1.132 + return M3G_FALSE;
1.133 + }
1.134 +
1.135 + if(m3gObjectDuplicate(originalObj, cloneObj, pairs, numPairs)) {
1.136 + clone->color = original->color;
1.137 + clone->density = original->density;
1.138 + clone->start = original->start;
1.139 + clone->end = original->end;
1.140 + clone->mode = original->mode;
1.141 + return M3G_TRUE;
1.142 + }
1.143 + else {
1.144 + return M3G_FALSE;
1.145 + }
1.146 +}
1.147 +
1.148 +/*!
1.149 + * \internal
1.150 + * \brief Initializes a Fog object. See specification
1.151 + * for default values.
1.152 + *
1.153 + * \param m3g M3G interface
1.154 + * \param fog Fog object
1.155 + */
1.156 +static void m3gInitFog(Interface *m3g, Fog *fog)
1.157 +{
1.158 + /* Fog is derived from object */
1.159 + m3gInitObject(&fog->object, m3g, M3G_CLASS_FOG);
1.160 +
1.161 + fog->density = 1.0f;
1.162 + fog->start = 0.0f;
1.163 + fog->end = 1.0f;
1.164 + fog->mode = M3G_LINEAR_FOG;
1.165 +}
1.166 +
1.167 +/*!
1.168 + * \internal
1.169 + * \brief Applies fog to OpenGL. This is used for
1.170 + * all Mesh objects.
1.171 + *
1.172 + * \param self Fog object
1.173 + */
1.174 +static void m3gApplyFog(const Fog *self)
1.175 +{
1.176 + if (self != NULL) {
1.177 + GLfixed temp[4];
1.178 +
1.179 + m3gGLColor(self->color, temp);
1.180 +
1.181 + switch (self->mode) {
1.182 + case M3G_LINEAR_FOG:
1.183 + glEnable(GL_FOG);
1.184 + glFogf(GL_FOG_MODE, GL_LINEAR);
1.185 + glFogf(GL_FOG_START, self->start);
1.186 + glFogf(GL_FOG_END, self->end);
1.187 + glFogxv(GL_FOG_COLOR, temp);
1.188 + break;
1.189 + case M3G_EXPONENTIAL_FOG:
1.190 + glEnable(GL_FOG);
1.191 + glFogf(GL_FOG_MODE, GL_EXP);
1.192 + glFogf(GL_FOG_DENSITY, self->density);
1.193 + glFogxv(GL_FOG_COLOR, temp);
1.194 + break;
1.195 + }
1.196 + }
1.197 + else {
1.198 + glDisable(GL_FOG);
1.199 + }
1.200 + M3G_ASSERT_GL;
1.201 +}
1.202 +
1.203 +#ifdef M3G_USE_NGL_API
1.204 +/*!
1.205 + * \internal
1.206 + * \brief Applies fog to NGL. This is used for
1.207 + * Sprite3D objects only.
1.208 + *
1.209 + * \param self Fog object
1.210 + * \param eyeZ Eye space Z (e.g. after modelview)
1.211 + * \param finalZ Final Z (e.g. after modelview and projection)
1.212 + */
1.213 +static void m3gApplySpriteFog(const Fog *self, M3Gfloat eyeZ, M3Gfloat finalZ)
1.214 +{
1.215 + if(self != NULL) {
1.216 + M3Gint temp[4];
1.217 + M3Gfloat fogValue = 1;
1.218 +
1.219 + /* Calculate fog value and use OpenGL linear fog
1.220 + * to result in same value. Sprites are drawn with
1.221 + * identity MV and P and therefore the fog has to
1.222 + * be adjusted like this */
1.223 + switch (self->mode) {
1.224 + case M3G_LINEAR_FOG:
1.225 + fogValue = m3gDiv(m3gAdd(self->end, eyeZ), m3gSub(self->end, self->start));
1.226 + break;
1.227 + case M3G_EXPONENTIAL_FOG:
1.228 + fogValue = m3gExp(m3gMul(self->density, eyeZ));
1.229 + break;
1.230 + default:
1.231 + M3G_ASSERT(M3G_FALSE);
1.232 + break;
1.233 + }
1.234 +
1.235 + m3gGLColor(self->color, temp);
1.236 +
1.237 + glEnable(GL_FOG);
1.238 + glFogf(GL_FOG_MODE, GL_LINEAR);
1.239 +
1.240 + /* NGL works differently in fog calculation */
1.241 + glFogf(GL_FOG_START, -m3gDiv(finalZ, fogValue));
1.242 + glFogf(GL_FOG_END, 0.f);
1.243 + glFogxv(GL_FOG_COLOR, temp);
1.244 + }
1.245 + else {
1.246 + glDisable(GL_FOG);
1.247 + }
1.248 +}
1.249 +#endif
1.250 +/*----------------------------------------------------------------------
1.251 + * Virtual function table
1.252 + *--------------------------------------------------------------------*/
1.253 +
1.254 +static const ObjectVFTable m3gvf_Fog = {
1.255 + m3gObjectApplyAnimation,
1.256 + m3gFogIsCompatible,
1.257 + m3gFogUpdateProperty,
1.258 + m3gObjectDoGetReferences,
1.259 + m3gObjectFindID,
1.260 + m3gFogDuplicate,
1.261 + m3gDestroyFog
1.262 +};
1.263 +
1.264 +
1.265 +/*----------------------------------------------------------------------
1.266 + * Public API functions
1.267 + *--------------------------------------------------------------------*/
1.268 +
1.269 +/*!
1.270 + * \brief Creates a Fog object.
1.271 + *
1.272 + * \param interface M3G interface
1.273 + * \retval Fog new Fog object
1.274 + * \retval NULL Fog creating failed
1.275 + */
1.276 +M3G_API M3GFog m3gCreateFog(M3GInterface interface)
1.277 +{
1.278 + Interface *m3g = (Interface *) interface;
1.279 + M3G_VALIDATE_INTERFACE(m3g);
1.280 +
1.281 + {
1.282 + Fog *fog = m3gAllocZ(m3g, sizeof(Fog));
1.283 +
1.284 + if (fog != NULL) {
1.285 + m3gInitFog(m3g, fog);
1.286 + }
1.287 +
1.288 + return (M3GFog) fog;
1.289 + }
1.290 +}
1.291 +
1.292 +/*!
1.293 + * \brief Sets fog mode.
1.294 + *
1.295 + * \param handle Fog object
1.296 + * \param mode fog mode
1.297 + */
1.298 +M3G_API void m3gSetFogMode(M3GFog handle, M3Gint mode)
1.299 +{
1.300 + Fog *fog = (Fog *) handle;
1.301 + M3G_VALIDATE_OBJECT(fog);
1.302 +
1.303 + /* Check for errors */
1.304 + if(mode < M3G_EXPONENTIAL_FOG || mode > M3G_LINEAR_FOG) {
1.305 + m3gRaiseError(M3G_INTERFACE(fog), M3G_INVALID_VALUE);
1.306 + return;
1.307 + }
1.308 +
1.309 + fog->mode = mode;
1.310 +}
1.311 +
1.312 +/*!
1.313 + * \brief Gets fog mode.
1.314 + *
1.315 + * \param handle Fog object
1.316 + * \return fog mode
1.317 + */
1.318 +M3G_API M3Gint m3gGetFogMode(M3GFog handle)
1.319 +{
1.320 + Fog *fog = (Fog *) handle;
1.321 + M3G_VALIDATE_OBJECT(fog);
1.322 +
1.323 + return fog->mode;
1.324 +}
1.325 +
1.326 +/*!
1.327 + * \brief Sets linear fog parameters.
1.328 + *
1.329 + * \param handle Fog object
1.330 + * \param fogNear near distance
1.331 + * \param fogFar far distance
1.332 + */
1.333 +M3G_API void m3gSetFogLinear(M3GFog handle, M3Gfloat fogNear, M3Gfloat fogFar)
1.334 +{
1.335 + Fog *fog = (Fog *) handle;
1.336 + M3G_VALIDATE_OBJECT(fog);
1.337 +
1.338 + fog->start = fogNear;
1.339 + fog->end = fogFar;
1.340 +}
1.341 +
1.342 +/*!
1.343 + * \brief Gets linear fog parameters.
1.344 + *
1.345 + * \param handle Fog object
1.346 + * \param which which parameter to return
1.347 + * \arg M3G_GET_NEAR
1.348 + * \arg M3G_GET_FAR
1.349 + * \return near or far distance
1.350 + */
1.351 +M3G_API M3Gfloat m3gGetFogDistance(M3GFog handle, M3Gint which)
1.352 +{
1.353 + Fog *fog = (Fog *) handle;
1.354 + M3G_VALIDATE_OBJECT(fog);
1.355 +
1.356 + switch(which) {
1.357 + case M3G_GET_NEAR:
1.358 + return fog->start;
1.359 + case M3G_GET_FAR:
1.360 + default:
1.361 + return fog->end;
1.362 + }
1.363 +}
1.364 +
1.365 +/*!
1.366 + * \brief Sets exponential fog density.
1.367 + *
1.368 + * \param handle Fog object
1.369 + * \param density fog density
1.370 + */
1.371 +M3G_API void m3gSetFogDensity(M3GFog handle, M3Gfloat density)
1.372 +{
1.373 + Fog *fog = (Fog *) handle;
1.374 + M3G_VALIDATE_OBJECT(fog);
1.375 +
1.376 + if(density < 0.f) {
1.377 + m3gRaiseError(M3G_INTERFACE(fog), M3G_INVALID_VALUE);
1.378 + return;
1.379 + }
1.380 +
1.381 + fog->density = density;
1.382 +}
1.383 +
1.384 +/*!
1.385 + * \brief Gets exponential fog density.
1.386 + *
1.387 + * \param handle Fog object
1.388 + * \return fog density
1.389 + */
1.390 +M3G_API M3Gfloat m3gGetFogDensity(M3GFog handle)
1.391 +{
1.392 + Fog *fog = (Fog *) handle;
1.393 + M3G_VALIDATE_OBJECT(fog);
1.394 +
1.395 + return fog->density;
1.396 +}
1.397 +
1.398 +/*!
1.399 + * \brief Sets fog color as RGB.
1.400 + *
1.401 + * \param handle Fog object
1.402 + * \param rgb fog color as RGB
1.403 + */
1.404 +M3G_API void m3gSetFogColor(M3GFog handle, M3Guint rgb)
1.405 +{
1.406 + Fog *fog = (Fog *) handle;
1.407 + M3G_VALIDATE_OBJECT(fog);
1.408 +
1.409 + fog->color = rgb & M3G_RGB_MASK;
1.410 +}
1.411 +
1.412 +/*!
1.413 + * \brief Gets fog color as RGB.
1.414 + *
1.415 + * \param handle Fog object
1.416 + * \return fog color as RGB
1.417 + */
1.418 +M3G_API M3Guint m3gGetFogColor(M3GFog handle)
1.419 +{
1.420 + Fog *fog = (Fog *) handle;
1.421 + M3G_VALIDATE_OBJECT(fog);
1.422 +
1.423 + return fog->color;
1.424 +}
1.425 +