shithub: tinygl

ref: 75e55346c70c831fe17df3f57379b280680e039e
dir: /src/light.c/

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#include "msghandling.h"
#include "zgl.h"

void glopMaterial(GLContext* c, GLParam* p) {
	GLint mode = p[1].i;
	GLint type = p[2].i;
	GLfloat v[4];
	v[0] = p[3].f;
	v[1] = p[4].f;
	v[2] = p[5].f;
	v[3] = p[6].f;
	GLint i;
	GLMaterial* m;

	if (mode == GL_FRONT_AND_BACK) {
		p[1].i = GL_FRONT;
		glopMaterial(c, p);
		mode = GL_BACK;
	}
	if (mode == GL_FRONT)
		m = &c->materials[0];
	else
		m = &c->materials[1];

	switch (type) {
	case GL_EMISSION:
		for (i = 0; i < 4; i++)
			m->emission.v[i] = v[i];
		break;
	case GL_AMBIENT:
		for (i = 0; i < 4; i++)
			m->ambient.v[i] = v[i];
		// c->current_color.X=v[0];
		// c->current_color.Y=v[1];
		// c->current_color.Z=v[2];
		// c->current_color.W=v[3];
		break;
	case GL_DIFFUSE:
		for (i = 0; i < 4; i++)
			m->diffuse.v[i] = v[i];

		// c->current_color.X=v[0];
		// c->current_color.Y=v[1];
		// c->current_color.Z=v[2];
		// c->current_color.W=v[3];
		break;
	case GL_SPECULAR:
		for (i = 0; i < 4; i++)
			m->specular.v[i] = v[i];
		break;
	case GL_SHININESS:
		m->shininess = v[0];
		m->shininess_i = (v[0] / 128.0f) * SPECULAR_BUFFER_SIZE;
		break;
	case GL_AMBIENT_AND_DIFFUSE:
		// printf("\nRECEIVED AMBIENT AND DIFFUSE COLOR %f, %f, %f, %f", v[0], v[1], v[2], v[3]);
		for (i = 0; i < 4; i++)
			m->diffuse.v[i] = v[i];
		// c->current_color.X=v[0];
		// c->current_color.Y=v[1];
		// c->current_color.Z=v[2];
		// c->current_color.W=v[3];

		for (i = 0; i < 4; i++)
			m->ambient.v[i] = v[i];
		break;
	default:
		c->current_color.X = v[0];
		c->current_color.Y = v[1];
		c->current_color.Z = v[2];
		c->current_color.W = v[3];
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#else
	//assert(0);
#endif
	}
}

void glopColorMaterial(GLContext* c, GLParam* p) {
	GLint mode = p[1].i;
	GLint type = p[2].i;

	c->current_color_material_mode = mode;
	c->current_color_material_type = type;
}

void glopLight(GLContext* c, GLParam* p) {
	GLint light = p[1].i;
	GLint type = p[2].i;
	V4 v;
	GLLight* l;
	GLint i;

	//assert(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS);

#if TGL_FEATURE_ERROR_CHECK == 1
	if(!(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS))
#define ERROR_FLAG GL_INVALID_OPERATION
#include "error_check.h"
#else
	//assert(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS);
#endif

	l = &c->lights[light - GL_LIGHT0];

	for (i = 0; i < 4; i++)
		v.v[i] = p[3 + i].f;

	switch (type) {
	case GL_AMBIENT:
		l->ambient = v;
		break;
	case GL_DIFFUSE:
		l->diffuse = v;
		break;
	case GL_SPECULAR:
		l->specular = v;
		break;
	case GL_POSITION: {
		V4 pos;
		gl_M4_MulV4(&pos, c->matrix_stack_ptr[0], &v);

		l->position = pos;

		if (l->position.v[3] == 0) {
			l->norm_position.X = pos.X;
			l->norm_position.Y = pos.Y;
			l->norm_position.Z = pos.Z;
			//gl_V3_Norm(&l->norm_position);
			gl_V3_Norm_Fast(&l->norm_position);
		}
	} break;
	case GL_SPOT_DIRECTION:
		for (i = 0; i < 3; i++) {
			l->spot_direction.v[i] = v.v[i];
			l->norm_spot_direction.v[i] = v.v[i];
		}
		gl_V3_Norm_Fast(&l->norm_spot_direction);
		break;
	case GL_SPOT_EXPONENT:
		l->spot_exponent = v.v[0];
		break;
	case GL_SPOT_CUTOFF: {
		GLfloat a = v.v[0];

#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_VALUE
#include "error_check.h"
#else
	//assert(a == 180 || (a >= 0 && a <= 90));
#endif

		l->spot_cutoff = a;
		if (a != 180)
			l->cos_spot_cutoff = cos(a * M_PI / 180.0);
	} break;
	case GL_CONSTANT_ATTENUATION:
		l->attenuation[0] = v.v[0];
		break;
	case GL_LINEAR_ATTENUATION:
		l->attenuation[1] = v.v[0];
		break;
	case GL_QUADRATIC_ATTENUATION:
		l->attenuation[2] = v.v[0];
		break;
	default:
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#endif
		return;
	}
}

void glopLightModel(GLContext* c, GLParam* p) {
	GLint pname = p[1].i;
	GLfloat* v = &p[2].f;
	GLint i;

	switch (pname) {
	case GL_LIGHT_MODEL_AMBIENT:
		for (i = 0; i < 4; i++)
			c->ambient_light_model.v[i] = p[2 + i].f;
		break;
	case GL_LIGHT_MODEL_LOCAL_VIEWER:
		c->local_light_model = (GLint)v[0];
		break;
	case GL_LIGHT_MODEL_TWO_SIDE:
		c->light_model_two_side = (GLint)v[0];
		break;
	default:
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#endif
//		tgl_warning("glopLightModel: illegal pname: 0x%x\n", pname);
		// assert(0);
		break;
	}
}

static inline GLfloat clampf(GLfloat a, GLfloat min, GLfloat max) {
	if (a < min)
		return min;
	else if (a > max)
		return max;
	else
		return a;
}

void gl_enable_disable_light(GLContext* c, GLint light, GLint v) {
	GLLight* l = &c->lights[light];
	if (v && !l->enabled) {
		l->enabled = 1;
		l->next = c->first_light;
		c->first_light = l;
		l->prev = NULL;
	} else if (!v && l->enabled) {
		l->enabled = 0;
		if (l->prev == NULL)
			c->first_light = l->next;
		else
			l->prev->next = l->next;
		if (l->next != NULL)
			l->next->prev = l->prev;
	}
}

// FEATURES
int zEnableSpecular = 1; // Enable specular lighting
void glSetEnableSpecular(GLint s) { 
#include "error_check_no_context.h"
	zEnableSpecular = s; 
}
/* non optimized lightening model */
void gl_shade_vertex(GLContext* c, GLVertex* v) {
	GLfloat R, G, B, A;
	GLMaterial* m;
	GLLight* l;
	V3 n, s, d;
	GLfloat dist, tmp, att, dot, dot_spot, dot_spec;
	GLint twoside = c->light_model_two_side;

	m = &c->materials[0];

	n.X = v->normal.X;
	n.Y = v->normal.Y;
	n.Z = v->normal.Z;

	R = m->emission.v[0] + m->ambient.v[0] * c->ambient_light_model.v[0];
	G = m->emission.v[1] + m->ambient.v[1] * c->ambient_light_model.v[1];
	B = m->emission.v[2] + m->ambient.v[2] * c->ambient_light_model.v[2];
	A = clampf(m->diffuse.v[3], 0, 1);

	for (l = c->first_light; l != NULL; l = l->next) {
		GLfloat lR, lB, lG;

		/* ambient */
		lR = l->ambient.v[0] * m->ambient.v[0];
		lG = l->ambient.v[1] * m->ambient.v[1];
		lB = l->ambient.v[2] * m->ambient.v[2];

		if (l->position.v[3] == 0) {
			/* light at infinity */
			// Fixed by Gek, it used to use the unnormalized position?
			d.X = l->norm_position.v[0];
			d.Y = l->norm_position.v[1];
			d.Z = l->norm_position.v[2];
			att = 1;
		} else {
			/* distance attenuation */
			d.X = l->position.v[0] - v->ec.v[0];
			d.Y = l->position.v[1] - v->ec.v[1];
			d.Z = l->position.v[2] - v->ec.v[2];
#if TGL_FEATURE_FISR == 1
			tmp = fastInvSqrt(d.X * d.X + d.Y * d.Y + d.Z * d.Z); //FISR IMPL, MATCHED!
			dist = 1.0f/tmp;
			if (dist > 1E-3) {
				d.X *= tmp;
				d.Y *= tmp;
				d.Z *= tmp;
			}
#else
			dist = sqrt(d.X * d.X + d.Y * d.Y + d.Z * d.Z);
			//dist = 1.0f/tmp;
			if (dist > 1E-3) {
				tmp = 1 / dist;
				d.X *= tmp;
				d.Y *= tmp;
				d.Z *= tmp;
			}
#endif
			att = 1.0f / (l->attenuation[0] + dist * (l->attenuation[1] + dist * l->attenuation[2]));
		}
		dot = d.X * n.X + d.Y * n.Y + d.Z * n.Z;
		if (twoside && dot < 0)
			dot = -dot;
		if (dot > 0) {
			/* diffuse light */
			lR += dot * l->diffuse.v[0] * m->diffuse.v[0];
			lG += dot * l->diffuse.v[1] * m->diffuse.v[1];
			lB += dot * l->diffuse.v[2] * m->diffuse.v[2];

			/* spot light */
			if (l->spot_cutoff != 180) {
				dot_spot = -(d.X * l->norm_spot_direction.v[0] + d.Y * l->norm_spot_direction.v[1] + d.Z * l->norm_spot_direction.v[2]);
				if (twoside && dot_spot < 0)
					dot_spot = -dot_spot;
				if (dot_spot < l->cos_spot_cutoff) {
					/* no contribution */
					continue;
				} else {
					/* TODO: optimize */
					if (l->spot_exponent > 0) {
						att = att * pow(dot_spot, l->spot_exponent);
					}
				}
				// GEK SAYS TO REMOVE THIS
				// printf("\nThis should not be being called.");
			}

			/* specular light */
			if (zEnableSpecular) {
				if (c->local_light_model) {
					V3 vcoord;
					vcoord.X = v->ec.X;
					vcoord.Y = v->ec.Y;
					vcoord.Z = v->ec.Z;
					//gl_V3_Norm(&vcoord);
					gl_V3_Norm_Fast(&vcoord);
					s.X = d.X - vcoord.X;
					s.Y = d.Y - vcoord.X;
					s.Z = d.Z - vcoord.X;
				} else {
					s.X = d.X;
					s.Y = d.Y;
					s.Z = d.Z + 1.0;
				}
				dot_spec = n.X * s.X + n.Y * s.Y + n.Z * s.Z;
				if (twoside && dot_spec < 0)
					dot_spec = -dot_spec;
				if (dot_spec > 0) {
					GLSpecBuf* specbuf;
					GLint idx;
#if TGL_FEATURE_FISR == 1
					tmp = fastInvSqrt(s.X * s.X + s.Y * s.Y + s.Z * s.Z); //FISR IMPL, MATCHED!
					if (tmp < 1E+3) {
						dot_spec = dot_spec * tmp;
					} else dot_spec = 0;
#else
				//reference implementation.
					tmp=sqrt(s.X*s.X+s.Y*s.Y+s.Z*s.Z);
			        if (tmp > 1E-3) {
			          dot_spec=dot_spec / tmp;
			        } else dot_spec = 0;
#endif
					

					/* TODO: optimize */
					/* testing specular buffer code */
					/* dot_spec= pow(dot_spec,m->shininess);*/
					specbuf = specbuf_get_buffer(c, m->shininess_i, m->shininess);
#if TGL_FEATURE_ERROR_CHECK == 1
//The GL_OUT_OF_MEMORY flag will already be set.
#include "error_check.h"
#else
				//As it turns out, this is actually handled inside of specbuf_get_buffer!
					//if(!specbuf)
					//	gl_fatal_error("BAD SPECBUF_GET_BUFFER");
#endif

					idx = (GLint)(dot_spec * SPECULAR_BUFFER_SIZE);
					if (idx > SPECULAR_BUFFER_SIZE)
						idx = SPECULAR_BUFFER_SIZE; //NOTE by GEK: this is poorly written, it's actually 1 larger.
					dot_spec = specbuf->buf[idx];
					lR += dot_spec * l->specular.v[0] * m->specular.v[0];
					lG += dot_spec * l->specular.v[1] * m->specular.v[1];
					lB += dot_spec * l->specular.v[2] * m->specular.v[2];
				} // EOF if dot_spec>0
			}	 // EOF zEnableSpecular
		}		  // EOF if dot > 0

		R += att * lR;
		G += att * lG;
		B += att * lB;
	} // End of light loop.

	v->color.v[0] = clampf(R, 0, 1);
	v->color.v[1] = clampf(G, 0, 1);
	v->color.v[2] = clampf(B, 0, 1);
	v->color.v[3] = A;
}