light.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  7.0
 *
 * 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.
 */


#include "glheader.h"
#include "imports.h"
#include "context.h"
#include "enums.h"
#include "light.h"
#include "macros.h"
#include "simple_list.h"
#include "mtypes.h"
#include "math/m_matrix.h"


void GLAPIENTRY
_mesa_ShadeModel( GLenum mode )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(ctx, "glShadeModel %s\n", _mesa_lookup_enum_by_nr(mode));

   if (mode != GL_FLAT && mode != GL_SMOOTH) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glShadeModel");
      return;
   }

   if (ctx->Light.ShadeModel == mode)
      return;

   FLUSH_VERTICES(ctx, _NEW_LIGHT);
   ctx->Light.ShadeModel = mode;
   if (mode == GL_FLAT)
      ctx->_TriangleCaps |= DD_FLATSHADE;
   else
      ctx->_TriangleCaps &= ~DD_FLATSHADE;

   if (ctx->Driver.ShadeModel)
      ctx->Driver.ShadeModel( ctx, mode );
}


/**
 * Helper function called by _mesa_Lightfv and _mesa_PopAttrib to set
 * per-light state.
 * For GL_POSITION and GL_SPOT_DIRECTION the params position/direction
 * will have already been transformed by the modelview matrix!
 * Also, all error checking should have already been done.
 */
void
_mesa_light(GLcontext *ctx, GLuint lnum, GLenum pname, const GLfloat *params)
{
   struct gl_light *light;

   ASSERT(lnum < MAX_LIGHTS);
   light = &ctx->Light.Light[lnum];

   switch (pname) {
   case GL_AMBIENT:
      if (TEST_EQ_4V(light->Ambient, params))
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Ambient, params );
      break;
   case GL_DIFFUSE:
      if (TEST_EQ_4V(light->Diffuse, params))
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Diffuse, params );
      break;
   case GL_SPECULAR:
      if (TEST_EQ_4V(light->Specular, params))
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V( light->Specular, params );
      break;
   case GL_POSITION:
      /* NOTE: position has already been transformed by ModelView! */
      if (TEST_EQ_4V(light->EyePosition, params))
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_4V(light->EyePosition, params);
      if (light->EyePosition[3] != 0.0F)
	 light->_Flags |= LIGHT_POSITIONAL;
      else
	 light->_Flags &= ~LIGHT_POSITIONAL;
      break;
   case GL_SPOT_DIRECTION:
      /* NOTE: Direction already transformed by inverse ModelView! */
      if (TEST_EQ_3V(light->EyeDirection, params))
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      COPY_3V(light->EyeDirection, params);
      break;
   case GL_SPOT_EXPONENT:
      ASSERT(params[0] >= 0.0);
      ASSERT(params[0] <= ctx->Const.MaxSpotExponent);
      if (light->SpotExponent == params[0])
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->SpotExponent = params[0];
      _mesa_invalidate_spot_exp_table(light);
      break;
   case GL_SPOT_CUTOFF:
      ASSERT(params[0] == 180.0 || (params[0] >= 0.0 && params[0] <= 90.0));
      if (light->SpotCutoff == params[0])
         return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->SpotCutoff = params[0];
      light->_CosCutoffNeg = (GLfloat) (_mesa_cos(light->SpotCutoff * DEG2RAD));
      if (light->_CosCutoffNeg < 0)
         light->_CosCutoff = 0;
      else
         light->_CosCutoff = light->_CosCutoffNeg;
      if (light->SpotCutoff != 180.0F)
         light->_Flags |= LIGHT_SPOT;
      else
         light->_Flags &= ~LIGHT_SPOT;
      break;
   case GL_CONSTANT_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->ConstantAttenuation == params[0])
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->ConstantAttenuation = params[0];
      break;
   case GL_LINEAR_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->LinearAttenuation == params[0])
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->LinearAttenuation = params[0];
      break;
   case GL_QUADRATIC_ATTENUATION:
      ASSERT(params[0] >= 0.0);
      if (light->QuadraticAttenuation == params[0])
	 return;
      FLUSH_VERTICES(ctx, _NEW_LIGHT);
      light->QuadraticAttenuation = params[0];
      break;
   default:
      _mesa_problem(ctx, "Unexpected pname in _mesa_light()");
      return;
   }

   if (ctx->Driver.Lightfv)
      ctx->Driver.Lightfv( ctx, GL_LIGHT0 + lnum, pname, params );
}


void GLAPIENTRY
_mesa_Lightf( GLenum light, GLenum pname, GLfloat param )
{
   _mesa_Lightfv( light, pname, &param );
}


void GLAPIENTRY
_mesa_Lightfv( GLenum light, GLenum pname, const GLfloat *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint i = (GLint) (light - GL_LIGHT0);
   GLfloat temp[4];
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (i < 0 || i >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glLight(light=0x%x)", light );
      return;
   }

   /* do particular error checks, transformations */
   switch (pname) {
   case GL_AMBIENT:
   case GL_DIFFUSE:
   case GL_SPECULAR:
      /* nothing */
      break;
   case GL_POSITION:
      /* transform position by ModelView matrix */
      TRANSFORM_POINT(temp, ctx->ModelviewMatrixStack.Top->m, params);
      params = temp;
      break;
   case GL_SPOT_DIRECTION:
      /* transform direction by inverse modelview */
      if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top)) {
	 _math_matrix_analyse(ctx->ModelviewMatrixStack.Top);
      }
      TRANSFORM_NORMAL(temp, params, ctx->ModelviewMatrixStack.Top->inv);
      params = temp;
      break;
   case GL_SPOT_EXPONENT:
      if (params[0] < 0.0 || params[0] > ctx->Const.MaxSpotExponent) {
	 _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
	 return;
      }
      break;
   case GL_SPOT_CUTOFF:
      if ((params[0] < 0.0 || params[0] > 90.0) && params[0] != 180.0) {
	 _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
	 return;
      }
      break;
   case GL_CONSTANT_ATTENUATION:
      if (params[0] < 0.0) {
	 _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
	 return;
      }
      break;
   case GL_LINEAR_ATTENUATION:
      if (params[0] < 0.0) {
	 _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
	 return;
      }
      break;
   case GL_QUADRATIC_ATTENUATION:
      if (params[0] < 0.0) {
	 _mesa_error(ctx, GL_INVALID_VALUE, "glLight");
	 return;
      }
      break;
   default:
      _mesa_error(ctx, GL_INVALID_ENUM, "glLight(pname=0x%x)", pname);
      return;
   }

   _mesa_light(ctx, i, pname, params);
}


void GLAPIENTRY
_mesa_Lighti( GLenum light, GLenum pname, GLint param )
{
   _mesa_Lightiv( light, pname, &param );
}


void GLAPIENTRY
_mesa_Lightiv( GLenum light, GLenum pname, const GLint *params )
{
   GLfloat fparam[4];

   switch (pname) {
      case GL_AMBIENT:
      case GL_DIFFUSE:
      case GL_SPECULAR:
         fparam[0] = INT_TO_FLOAT( params[0] );
         fparam[1] = INT_TO_FLOAT( params[1] );
         fparam[2] = INT_TO_FLOAT( params[2] );
         fparam[3] = INT_TO_FLOAT( params[3] );
         break;
      case GL_POSITION:
         fparam[0] = (GLfloat) params[0];
         fparam[1] = (GLfloat) params[1];
         fparam[2] = (GLfloat) params[2];
         fparam[3] = (GLfloat) params[3];
         break;
      case GL_SPOT_DIRECTION:
         fparam[0] = (GLfloat) params[0];
         fparam[1] = (GLfloat) params[1];
         fparam[2] = (GLfloat) params[2];
         break;
      case GL_SPOT_EXPONENT:
      case GL_SPOT_CUTOFF:
      case GL_CONSTANT_ATTENUATION:
      case GL_LINEAR_ATTENUATION:
      case GL_QUADRATIC_ATTENUATION:
         fparam[0] = (GLfloat) params[0];
         break;
      default:
         /* error will be caught later in gl_Lightfv */
         ;
   }

   _mesa_Lightfv( light, pname, fparam );
}



void GLAPIENTRY
_mesa_GetLightfv( GLenum light, GLenum pname, GLfloat *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint l = (GLint) (light - GL_LIGHT0);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
      return;
   }

   switch (pname) {
      case GL_AMBIENT:
         COPY_4V( params, ctx->Light.Light[l].Ambient );
         break;
      case GL_DIFFUSE:
         COPY_4V( params, ctx->Light.Light[l].Diffuse );
         break;
      case GL_SPECULAR:
         COPY_4V( params, ctx->Light.Light[l].Specular );
         break;
      case GL_POSITION:
         COPY_4V( params, ctx->Light.Light[l].EyePosition );
         break;
      case GL_SPOT_DIRECTION:
         COPY_3V( params, ctx->Light.Light[l].EyeDirection );
         break;
      case GL_SPOT_EXPONENT:
         params[0] = ctx->Light.Light[l].SpotExponent;
         break;
      case GL_SPOT_CUTOFF:
         params[0] = ctx->Light.Light[l].SpotCutoff;
         break;
      case GL_CONSTANT_ATTENUATION:
         params[0] = ctx->Light.Light[l].ConstantAttenuation;
         break;
      case GL_LINEAR_ATTENUATION:
         params[0] = ctx->Light.Light[l].LinearAttenuation;
         break;
      case GL_QUADRATIC_ATTENUATION:
         params[0] = ctx->Light.Light[l].QuadraticAttenuation;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
         break;
   }
}


void GLAPIENTRY
_mesa_GetLightiv( GLenum light, GLenum pname, GLint *params )
{
   GET_CURRENT_CONTEXT(ctx);
   GLint l = (GLint) (light - GL_LIGHT0);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
      return;
   }

   switch (pname) {
      case GL_AMBIENT:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[3]);
         break;
      case GL_DIFFUSE:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[3]);
         break;
      case GL_SPECULAR:
         params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[0]);
         params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[1]);
         params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[2]);
         params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[3]);
         break;
      case GL_POSITION:
         params[0] = (GLint) ctx->Light.Light[l].EyePosition[0];
         params[1] = (GLint) ctx->Light.Light[l].EyePosition[1];
         params[2] = (GLint) ctx->Light.Light[l].EyePosition[2];
         params[3] = (GLint) ctx->Light.Light[l].EyePosition[3];
         break;
      case GL_SPOT_DIRECTION:
         params[0] = (GLint) ctx->Light.Light[l].EyeDirection[0];
         params[1] = (GLint) ctx->Light.Light[l].EyeDirection[1];
         params[2] = (GLint) ctx->Light.Light[l].EyeDirection[2];
         break;
      case GL_SPOT_EXPONENT:
         params[0] = (GLint) ctx->Light.Light[l].SpotExponent;
         break;
      case GL_SPOT_CUTOFF:
         params[0] = (GLint) ctx->Light.Light[l].SpotCutoff;
         break;
      case GL_CONSTANT_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].ConstantAttenuation;
         break;
      case GL_LINEAR_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].LinearAttenuation;
         break;
      case GL_QUADRATIC_ATTENUATION:
         params[0] = (GLint) ctx->Light.Light[l].QuadraticAttenuation;
         break;
      default:
         _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
         break;
   }
}



/**********************************************************************/
/***                        Light Model                             ***/
/**********************************************************************/


void GLAPIENTRY
_mesa_LightModelfv( GLenum pname, const GLfloat *params )
{
   GLenum newenum;
   GLboolean newbool;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   switch (pname) {
      case GL_LIGHT_MODEL_AMBIENT:
         if (TEST_EQ_4V( ctx->Light.Model.Ambient, params ))
	    return;
	 FLUSH_VERTICES(ctx, _NEW_LIGHT);
         COPY_4V( ctx->Light.Model.Ambient, params );
         break;
      case GL_LIGHT_MODEL_LOCAL_VIEWER:
         newbool = (params[0]!=0.0);
	 if (ctx->Light.Model.LocalViewer == newbool)
	    return;
	 FLUSH_VERTICES(ctx, _NEW_LIGHT);
	 ctx->Light.Model.LocalViewer = newbool;
         break;
      case GL_LIGHT_MODEL_TWO_SIDE:
         newbool = (params[0]!=0.0);
	 if (ctx->Light.Model.TwoSide == newbool)
	    return;
	 FLUSH_VERTICES(ctx, _NEW_LIGHT);
	 ctx->Light.Model.TwoSide = newbool;
         if (ctx->Light.Enabled && ctx->Light.Model.TwoSide)
            ctx->_TriangleCaps |= DD_TRI_LIGHT_TWOSIDE;
         else
            ctx->_TriangleCaps &= ~DD_TRI_LIGHT_TWOSIDE;
         break;
      case GL_LIGHT_MODEL_COLOR_CONTROL:
         if (params[0] == (GLfloat) GL_SINGLE_COLOR)
	    newenum = GL_SINGLE_COLOR;
         else if (params[0] == (GLfloat) GL_SEPARATE_SPECULAR_COLOR)
	    newenum = GL_SEPARATE_SPECULAR_COLOR;
	 else {
            _mesa_error( ctx, GL_INVALID_ENUM, "glLightModel(param=0x0%x)",
                         (GLint) params[0] );
	    return;