ref: 3b961717be648d0810bb364e3cacbd4be8f7ce0b
dir: /src/matrix.c/
#include "zgl.h"
void gl_print_matrix( const GLfloat *m)
{
GLint i;
for (i=0;i<4;i++) {
fprintf(stderr,"%f %f %f %f\n", m[i], m[4+i], m[8+i], m[12+i] );
}
}
static inline void gl_matrix_update(GLContext *c)
{
c->matrix_model_projection_updated=(c->matrix_mode<=1);
}
void glopMatrixMode(GLContext *c,GLParam *p)
{
GLint mode=p[1].i;
switch(mode) {
case GL_MODELVIEW:
c->matrix_mode=0;
break;
case GL_PROJECTION:
c->matrix_mode=1;
break;
case GL_TEXTURE:
c->matrix_mode=2;
break;
default:
assert(0);
}
}
void glopLoadMatrix(GLContext *c,GLParam *p)
{
M4 *m;
GLint i;
GLParam *q;
m=c->matrix_stack_ptr[c->matrix_mode];
q=p+1;
for(i=0;i<4;i++) {
m->m[0][i]=q[0].f;
m->m[1][i]=q[1].f;
m->m[2][i]=q[2].f;
m->m[3][i]=q[3].f;
q+=4;
}
gl_matrix_update(c);
}
void glopLoadIdentity(GLContext *c,GLParam *p)
{
gl_M4_Id(c->matrix_stack_ptr[c->matrix_mode]);
gl_matrix_update(c);
}
void glopMultMatrix(GLContext *c,GLParam *p)
{
M4 m;
GLint i;
GLParam *q;
q=p+1;
for(i=0;i<4;i++) {
m.m[0][i]=q[0].f;
m.m[1][i]=q[1].f;
m.m[2][i]=q[2].f;
m.m[3][i]=q[3].f;
q+=4;
}
gl_M4_MulLeft(c->matrix_stack_ptr[c->matrix_mode],&m);
gl_matrix_update(c);
}
void glopPushMatrix(GLContext *c,GLParam *p)
{
GLint n=c->matrix_mode;
M4 *m;
assert( (c->matrix_stack_ptr[n] - c->matrix_stack[n] + 1 )
< c->matrix_stack_depth_max[n] );
m=++c->matrix_stack_ptr[n];
gl_M4_Move(&m[0],&m[-1]);
gl_matrix_update(c);
}
void glopPopMatrix(GLContext *c,GLParam *p)
{
GLint n=c->matrix_mode;
assert( c->matrix_stack_ptr[n] > c->matrix_stack[n] );
c->matrix_stack_ptr[n]--;
gl_matrix_update(c);
}
void glopRotate(GLContext *c,GLParam *p)
{
M4 m;
GLfloat u[3];
GLfloat angle;
GLint dir_code;
angle = p[1].f * M_PI / 180.0;
u[0]=p[2].f;
u[1]=p[3].f;
u[2]=p[4].f;
/* simple case detection */
dir_code = ((u[0] != 0)<<2) | ((u[1] != 0)<<1) | (u[2] != 0);
switch(dir_code) {
case 0:
gl_M4_Id(&m);
break;
case 4:
if (u[0] < 0) angle=-angle;
gl_M4_Rotate(&m,angle,0);
break;
case 2:
if (u[1] < 0) angle=-angle;
gl_M4_Rotate(&m,angle,1);
break;
case 1:
if (u[2] < 0) angle=-angle;
gl_M4_Rotate(&m,angle,2);
break;
default:
{
GLfloat cost, sint;
/* normalize vector */
GLfloat len = u[0]*u[0]+u[1]*u[1]+u[2]*u[2];
if (len == 0.0f) return;
len = 1.0f / sqrt(len);
u[0] *= len;
u[1] *= len;
u[2] *= len;
/* store cos and sin values */
cost=cos(angle);
sint=sin(angle);
/* fill in the values */
m.m[3][0]=m.m[3][1]=m.m[3][2]=
m.m[0][3]=m.m[1][3]=m.m[2][3]=0.0f;
m.m[3][3]=1.0f;
/* do the math */
m.m[0][0]=u[0]*u[0]+cost*(1-u[0]*u[0]);
m.m[1][0]=u[0]*u[1]*(1-cost)-u[2]*sint;
m.m[2][0]=u[2]*u[0]*(1-cost)+u[1]*sint;
m.m[0][1]=u[0]*u[1]*(1-cost)+u[2]*sint;
m.m[1][1]=u[1]*u[1]+cost*(1-u[1]*u[1]);
m.m[2][1]=u[1]*u[2]*(1-cost)-u[0]*sint;
m.m[0][2]=u[2]*u[0]*(1-cost)-u[1]*sint;
m.m[1][2]=u[1]*u[2]*(1-cost)+u[0]*sint;
m.m[2][2]=u[2]*u[2]+cost*(1-u[2]*u[2]);
}
}
gl_M4_MulLeft(c->matrix_stack_ptr[c->matrix_mode],&m);
gl_matrix_update(c);
}
void glopScale(GLContext *c,GLParam *p)
{
GLfloat *m;
GLfloat x=p[1].f,y=p[2].f,z=p[3].f;
m=&c->matrix_stack_ptr[c->matrix_mode]->m[0][0];
m[0] *= x; m[1] *= y; m[2] *= z;
m[4] *= x; m[5] *= y; m[6] *= z;
m[8] *= x; m[9] *= y; m[10] *= z;
m[12] *= x; m[13] *= y; m[14] *= z;
gl_matrix_update(c);
}
void glopTranslate(GLContext *c,GLParam *p)
{
GLfloat *m;
GLfloat x=p[1].f,y=p[2].f,z=p[3].f;
m=&c->matrix_stack_ptr[c->matrix_mode]->m[0][0];
m[3] = m[0] * x + m[1] * y + m[2] * z + m[3];
m[7] = m[4] * x + m[5] * y + m[6] * z + m[7];
m[11] = m[8] * x + m[9] * y + m[10] * z + m[11];
m[15] = m[12] * x + m[13] * y + m[14] * z + m[15];
gl_matrix_update(c);
}
void glopFrustum(GLContext *c,GLParam *p)
{
GLfloat *r;
M4 m;
GLfloat left=p[1].f;
GLfloat right=p[2].f;
GLfloat bottom=p[3].f;
GLfloat top=p[4].f;
GLfloat near=p[5].f;
GLfloat farp=p[6].f;
GLfloat x,y,A,B,C,D;
x = (2.0*near) / (right-left);
y = (2.0*near) / (top-bottom);
A = (right+left) / (right-left);
B = (top+bottom) / (top-bottom);
C = -(farp+near) / ( farp-near);
D = -(2.0*farp*near) / (farp-near);
r=&m.m[0][0];
r[0]= x; r[1]=0; r[2]=A; r[3]=0;
r[4]= 0; r[5]=y; r[6]=B; r[7]=0;
r[8]= 0; r[9]=0; r[10]=C; r[11]=D;
r[12]= 0; r[13]=0; r[14]=-1; r[15]=0;
gl_M4_MulLeft(c->matrix_stack_ptr[c->matrix_mode],&m);
gl_matrix_update(c);
}