GLdc/GL/lighting.c
2019-08-01 20:21:13 +01:00

429 lines
13 KiB
C

#include <stdio.h>
#include <string.h>
#include <dc/vec3f.h>
#include "private.h"
static GLfloat SCENE_AMBIENT [] = {0.2, 0.2, 0.2, 1.0};
static GLboolean VIEWER_IN_EYE_COORDINATES = GL_TRUE;
static GLenum COLOR_CONTROL = GL_SINGLE_COLOR;
static GLboolean TWO_SIDED_LIGHTING = GL_FALSE;
static GLenum COLOR_MATERIAL_MODE = GL_AMBIENT_AND_DIFFUSE;
static LightSource LIGHTS[MAX_LIGHTS];
static Material MATERIAL;
void _glInitLights() {
static GLfloat ONE [] = {1.0f, 1.0f, 1.0f, 1.0f};
static GLfloat ZERO [] = {0.0f, 0.0f, 0.0f, 1.0f};
static GLfloat PARTIAL [] = {0.2f, 0.2f, 0.2f, 1.0f};
static GLfloat MOSTLY [] = {0.8f, 0.8f, 0.8f, 1.0f};
memcpy(MATERIAL.ambient, PARTIAL, sizeof(GLfloat) * 4);
memcpy(MATERIAL.diffuse, MOSTLY, sizeof(GLfloat) * 4);
memcpy(MATERIAL.specular, ZERO, sizeof(GLfloat) * 4);
memcpy(MATERIAL.emissive, ZERO, sizeof(GLfloat) * 4);
MATERIAL.exponent = 0.0f;
GLubyte i;
for(i = 0; i < MAX_LIGHTS; ++i) {
memcpy(LIGHTS[i].ambient, ZERO, sizeof(GLfloat) * 4);
memcpy(LIGHTS[i].diffuse, ONE, sizeof(GLfloat) * 4);
memcpy(LIGHTS[i].specular, ONE, sizeof(GLfloat) * 4);
if(i > 0) {
memcpy(LIGHTS[i].diffuse, ZERO, sizeof(GLfloat) * 4);
memcpy(LIGHTS[i].specular, ZERO, sizeof(GLfloat) * 4);
}
LIGHTS[i].position[0] = LIGHTS[i].position[1] = LIGHTS[i].position[3] = 0.0f;
LIGHTS[i].position[2] = 1.0f;
LIGHTS[i].spot_direction[0] = LIGHTS[i].spot_direction[1] = 0.0f;
LIGHTS[i].spot_direction[2] = -1.0f;
LIGHTS[i].spot_exponent = 0.0f;
LIGHTS[i].spot_cutoff = 180.0f;
LIGHTS[i].constant_attenuation = 1.0f;
LIGHTS[i].linear_attenuation = 0.0f;
LIGHTS[i].quadratic_attenuation = 0.0f;
LIGHTS[i].is_directional = GL_FALSE;
}
}
void APIENTRY glLightModelf(GLenum pname, const GLfloat param) {
glLightModelfv(pname, &param);
}
void APIENTRY glLightModeli(GLenum pname, const GLint param) {
glLightModeliv(pname, &param);
}
void APIENTRY glLightModelfv(GLenum pname, const GLfloat *params) {
switch(pname) {
case GL_LIGHT_MODEL_AMBIENT:
memcpy(SCENE_AMBIENT, params, sizeof(GLfloat) * 4);
break;
case GL_LIGHT_MODEL_LOCAL_VIEWER:
VIEWER_IN_EYE_COORDINATES = (*params) ? GL_TRUE : GL_FALSE;
break;
case GL_LIGHT_MODEL_TWO_SIDE:
/* Not implemented */
default:
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
}
}
void APIENTRY glLightModeliv(GLenum pname, const GLint* params) {
switch(pname) {
case GL_LIGHT_MODEL_COLOR_CONTROL:
COLOR_CONTROL = *params;
break;
case GL_LIGHT_MODEL_LOCAL_VIEWER:
VIEWER_IN_EYE_COORDINATES = (*params) ? GL_TRUE : GL_FALSE;
break;
default:
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
}
}
void APIENTRY glLightfv(GLenum light, GLenum pname, const GLfloat *params) {
GLubyte idx = light & 0xF;
if(idx >= MAX_LIGHTS) {
return;
}
switch(pname) {
case GL_AMBIENT:
memcpy(LIGHTS[idx].ambient, params, sizeof(GLfloat) * 4);
break;
case GL_DIFFUSE:
memcpy(LIGHTS[idx].diffuse, params, sizeof(GLfloat) * 4);
break;
case GL_SPECULAR:
memcpy(LIGHTS[idx].specular, params, sizeof(GLfloat) * 4);
break;
case GL_POSITION: {
_glMatrixLoadModelView();
memcpy(LIGHTS[idx].position, params, sizeof(GLfloat) * 4);
LIGHTS[idx].is_directional = (params[3] == 0.0f) ? GL_TRUE : GL_FALSE;
if(LIGHTS[idx].is_directional) {
//FIXME: Do we need to rotate directional lights?
} else {
mat_trans_single4(
LIGHTS[idx].position[0],
LIGHTS[idx].position[1],
LIGHTS[idx].position[2],
LIGHTS[idx].position[3]
);
}
}
break;
case GL_SPOT_DIRECTION: {
LIGHTS[idx].spot_direction[0] = params[0];
LIGHTS[idx].spot_direction[1] = params[1];
LIGHTS[idx].spot_direction[2] = params[2];
} break;
case GL_CONSTANT_ATTENUATION:
case GL_LINEAR_ATTENUATION:
case GL_QUADRATIC_ATTENUATION:
case GL_SPOT_CUTOFF:
case GL_SPOT_EXPONENT:
glLightf(light, pname, *params);
break;
default:
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
}
}
void APIENTRY glLightf(GLenum light, GLenum pname, GLfloat param) {
GLubyte idx = light & 0xF;
if(idx >= MAX_LIGHTS) {
return;
}
switch(pname) {
case GL_CONSTANT_ATTENUATION:
LIGHTS[idx].constant_attenuation = param;
break;
case GL_LINEAR_ATTENUATION:
LIGHTS[idx].linear_attenuation = param;
break;
case GL_QUADRATIC_ATTENUATION:
LIGHTS[idx].quadratic_attenuation = param;
break;
case GL_SPOT_EXPONENT:
LIGHTS[idx].spot_exponent = param;
break;
case GL_SPOT_CUTOFF:
LIGHTS[idx].spot_cutoff = param;
break;
default:
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
}
}
void APIENTRY glMaterialf(GLenum face, GLenum pname, const GLfloat param) {
if(face == GL_BACK || pname != GL_SHININESS) {
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
return;
}
MATERIAL.exponent = param;
}
void APIENTRY glMateriali(GLenum face, GLenum pname, const GLint param) {
glMaterialf(face, pname, param);
}
void APIENTRY glMaterialfv(GLenum face, GLenum pname, const GLfloat *params) {
if(pname == GL_SHININESS) {
glMaterialf(face, pname, *params);
return;
}
if(face == GL_BACK) {
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
return;
}
switch(pname) {
case GL_AMBIENT:
memcpy(MATERIAL.ambient, params, sizeof(GLfloat) * 4);
break;
case GL_DIFFUSE:
memcpy(MATERIAL.diffuse, params, sizeof(GLfloat) * 4);
break;
case GL_SPECULAR:
memcpy(MATERIAL.specular, params, sizeof(GLfloat) * 4);
break;
case GL_EMISSION:
memcpy(MATERIAL.specular, params, sizeof(GLfloat) * 4);
break;
case GL_AMBIENT_AND_DIFFUSE: {
glMaterialfv(face, GL_AMBIENT, params);
glMaterialfv(face, GL_DIFFUSE, params);
} break;
case GL_COLOR_INDEXES:
default: {
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
}
}
}
void APIENTRY glColorMaterial(GLenum face, GLenum mode) {
if(face != GL_FRONT_AND_BACK) {
_glKosThrowError(GL_INVALID_ENUM, __func__);
_glKosPrintError();
return;
}
GLint validModes[] = {GL_AMBIENT, GL_DIFFUSE, GL_AMBIENT_AND_DIFFUSE, GL_EMISSION, GL_SPECULAR, 0};
if(_glCheckValidEnum(mode, validModes, __func__) != 0) {
return;
}
COLOR_MATERIAL_MODE = mode;
}
static inline GLboolean isDiffuseColorMaterial() {
return (COLOR_MATERIAL_MODE == GL_DIFFUSE || COLOR_MATERIAL_MODE == GL_AMBIENT_AND_DIFFUSE);
}
static inline GLboolean isAmbientColorMaterial() {
return (COLOR_MATERIAL_MODE == GL_AMBIENT || COLOR_MATERIAL_MODE == GL_AMBIENT_AND_DIFFUSE);
}
static inline GLboolean isSpecularColorMaterial() {
return (COLOR_MATERIAL_MODE == GL_SPECULAR);
}
static inline void initVec3(struct vec3f* v, const GLfloat* src) {
memcpy(v, src, sizeof(GLfloat) * 3);
}
/* Fast POW Implementation - Less accurate, but much faster than math.h */
#define EXP_A 184
#define EXP_C 16249
static inline float FEXP(float y) {
union {
float d;
struct {
short j, i;
} n;
} eco;
eco.n.i = EXP_A * (y) + (EXP_C);
eco.n.j = 0;
return eco.d;
}
static inline float FLOG(float y) {
int *nTemp = (int *)&y;
y = (*nTemp) >> 16;
return (y - EXP_C) / EXP_A;
}
static inline float FPOW(float b, float p) {
return FEXP(FLOG(b) * p);
}
void _glCalculateLighting(EyeSpaceData* ES, Vertex* vertex) {
/* Before we begin, lets fiddle some pointers if COLOR_MATERIAL
* is enabled */
const GLboolean colorMaterial = _glIsColorMaterialEnabled();
const GLboolean isDiffuseCM = isDiffuseColorMaterial();
const GLboolean isAmbientCM = isAmbientColorMaterial();
const GLboolean isSpecularCM = isSpecularColorMaterial();
static GLfloat CM[4];
if(colorMaterial) {
CM[0] = ((GLfloat) vertex->bgra[R8IDX]) / 255.0f;
CM[1] = ((GLfloat) vertex->bgra[G8IDX]) / 255.0f;
CM[2] = ((GLfloat) vertex->bgra[B8IDX]) / 255.0f;
CM[3] = ((GLfloat) vertex->bgra[A8IDX]) / 255.0f;
}
const GLfloat* MD = (colorMaterial && isDiffuseCM) ? CM : MATERIAL.diffuse;
const GLfloat* MA = (colorMaterial && isAmbientCM) ? CM : MATERIAL.ambient;
const GLfloat* MS = (colorMaterial && isSpecularCM) ? CM : MATERIAL.specular;
/* Right..
*
* global propertie:
*
* acs - Global Ambient
*
* vertex-specific properties:
*
* ecm - Material Emission
* acm - Material Ambient
* dcm - Material Diffuse
* n - Normal
* V - Vertex Position
* VPe - Vector from V to eye point (0, 0, 0, -1) basically negative V
*
* light-specifc properties:
*
* att - Attenution
* acli - Light Ambient
* Ppli - Light Position
* dcli - Light Diffuse
* fi - 1/0 facing light or not
* VPpli - Vector from V to Ppli
* ndotPpli - Dot product between n and Ppli
* hi -
* PpliV - vector from Ppli to V
*/
/* Each colour component is calculated in its own scope
* so that the SH4 float registers don't get flooded */
#define LIGHT_COMPONENT(C) { \
const GLfloat acm = MA[C]; \
const GLfloat dcm = MD[C]; \
const GLfloat scm = MS[C]; \
const GLfloat scli = light->specular[C]; \
const GLfloat dcli = light->diffuse[C]; \
const GLfloat acli = light->ambient[C]; \
const GLfloat srm = MATERIAL.exponent; \
\
final[C] += (att * spot * ( \
(acm * acli) + (ndotVPpli * dcm * dcli) + \
(FPOW((fi * ndothi), srm) * scm * scli) \
)); \
}
const GLfloat* n = ES->n;
const GLfloat* V = ES->xyz;
GLfloat Vpe [] = {-V[0], -V[1], -V[2]};
GLfloat VpeL;
vec3f_length(Vpe[0], Vpe[1], Vpe[2], VpeL);
Vpe[0] /= VpeL;
Vpe[1] /= VpeL;
Vpe[2] /= VpeL;
GLfloat final[4] = {
MATERIAL.emissive[0] + (MA[0] * SCENE_AMBIENT[0]),
MATERIAL.emissive[1] + (MA[1] * SCENE_AMBIENT[1]),
MATERIAL.emissive[2] + (MA[2] * SCENE_AMBIENT[2]),
MD[3] // GL spec says alpha is always from the diffuse
};
GLubyte i;
for(i = 0; i < MAX_LIGHTS; ++i) {
if(!_glIsLightEnabled(i)) continue;
const LightSource* light = &LIGHTS[i];
const GLfloat* Ppli = light->position;
GLfloat VPpli [] = {
Ppli[0] - V[0],
Ppli[1] - V[1],
Ppli[2] - V[2]
};
GLfloat VPpliL;
vec3f_length(VPpli[0], VPpli[1], VPpli[2], VPpliL);
VPpli[0] /= VPpliL;
VPpli[1] /= VPpliL;
VPpli[2] /= VPpliL;
GLfloat ndotVPpli;
vec3f_dot(n[0], n[1], n[2], VPpli[0], VPpli[1], VPpli[2], ndotVPpli);
const GLfloat k0 = light->constant_attenuation;
const GLfloat k1 = light->linear_attenuation;
const GLfloat k2 = light->quadratic_attenuation;
const GLfloat att = (light->position[3] == 0) ? 1.0f : 1.0f / k0 + (k1 * VPpliL) + (k2 * VPpliL * VPpliL);
const GLfloat spot = 1.0f; // FIXME: Spotlights
const GLfloat fi = (ndotVPpli == 0) ? 0 : 1;
GLfloat hi [3];
if(!VIEWER_IN_EYE_COORDINATES) {
// FIXME: Docs show power of T or something?
hi[0] = VPpli[0] + 0;
hi[1] = VPpli[1] + 0;
hi[2] = VPpli[2] + 1;
} else {
hi[0] = VPpli[0] + Vpe[0];
hi[1] = VPpli[1] + Vpe[1];
hi[2] = VPpli[2] + Vpe[2];
}
GLfloat ndothi;
vec3f_dot(n[0], n[1], n[2], hi[0], hi[1], hi[2], ndothi);
LIGHT_COMPONENT(0);
LIGHT_COMPONENT(1);
LIGHT_COMPONENT(2);
}
#undef LIGHT_COMPONENT
vertex->bgra[R8IDX] = (GLubyte)(fminf(final[0] * 255.0f, 255.0f));
vertex->bgra[G8IDX] = (GLubyte)(fminf(final[1] * 255.0f, 255.0f));
vertex->bgra[B8IDX] = (GLubyte)(fminf(final[2] * 255.0f, 255.0f));
vertex->bgra[A8IDX] = (GLubyte)(fminf(final[3] * 255.0f, 255.0f));
}