113 lines
2.5 KiB
C
113 lines
2.5 KiB
C
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#include <string.h>
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#include <cc65.h>
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#include "vec3d.h"
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const Matrix IDENTITY = {{{127,0,0},{0,127,0},{0,0,127}}};
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void mat_identity(Matrix* m) {
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*m = IDENTITY;
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}
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void vec_mat_transform(Vector16* dest, const Vector8* v, const Matrix* m) {
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byte i;
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int* result = &dest->x;
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const sbyte* mval = &m->m[0][0];
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for (i=0; i<3; i++) {
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*result++ = imul8x8r16(*mval++, v->x)
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+ imul8x8r16(*mval++, v->y)
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+ imul8x8r16(*mval++, v->z);
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}
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}
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/*
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void vec_mat_transform2(Vector16* dest, const Vector8* v, const Matrix* m) {
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dest->x = v->x*m->m[0][0] + v->y*m->m[0][1] + v->z*m->m[0][2];
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dest->y = v->x*m->m[1][0] + v->y*m->m[1][1] + v->z*m->m[1][2];
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dest->z = v->x*m->m[2][0] + v->y*m->m[2][1] + v->z*m->m[2][2];
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}
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*/
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const sbyte sintbl[64] = {
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0, 3, 6, 9, 12, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43, 46,
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49, 51, 54, 57, 60, 63, 65, 68, 71, 73, 76, 78, 81, 83, 85, 88,
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90, 92, 94, 96, 98, 100, 102, 104, 106, 107, 109, 111, 112, 113, 115, 116,
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117, 118, 120, 121, 122, 122, 123, 124, 125, 125, 126, 126, 126, 127, 127, 127,
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};
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sbyte isin(byte x0) {
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byte x = x0;
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if (x0 & 0x40) x = 127-x;
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if (x0 & 0x80) {
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return -sintbl[x-128];
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} else {
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return sintbl[x];
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}
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}
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sbyte icos(byte x) {
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return isin(x+64);
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}
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void mat_rotate(Matrix* m, byte axis, byte angle) {
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sbyte sin = -isin(angle);
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sbyte cos = icos(angle);
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mat_identity(m);
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switch (axis) {
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case 0:
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m->m[1][1] = cos;
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m->m[2][1] = sin;
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m->m[1][2] = -sin;
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m->m[2][2] = cos;
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break;
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case 1:
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m->m[2][2] = cos;
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m->m[0][2] = sin;
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m->m[2][0] = -sin;
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m->m[0][0] = cos;
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break;
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case 2:
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m->m[0][0] = cos;
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m->m[1][0] = sin;
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m->m[0][1] = -sin;
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m->m[1][1] = cos;
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break;
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}
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}
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void xform_vertices(Vector16* dest, const Vector8* src, const Matrix* m, byte nv) {
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byte i;
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for (i=0; i<nv; i++) {
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vec_mat_transform(dest++, src++, m);
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}
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}
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void draw_wireframe(const Wireframe* wf, Vector16* scrnverts) {
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const sbyte* e = wf->edges;
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byte bright = 0;
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int x1 = 0;
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int y1 = 0;
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do {
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sbyte i = *e++;
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if (i == -1)
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bright = 0;
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else if (i == -2)
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break;
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else {
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int x2 = scrnverts[i].x>>8;
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int y2 = scrnverts[i].y>>8;
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VCTR(x2-x1, y2-y1, bright);
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x1 = x2;
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y1 = y2;
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}
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bright = 2;
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} while (1);
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}
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void draw_wireframe_ortho(const Wireframe* wf, const Matrix* m) {
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Vector16 scrnverts[16];
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xform_vertices(scrnverts, wf->verts, m, wf->numverts);
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draw_wireframe(wf, scrnverts);
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}
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