Fred Barnes / gfx3d

Basic 3D graphics for the MBED application-shield on-board LCD (initial/incomplete).

Dependents:   co657_lcdplay

gfx3d.cpp@2:f62652cae975, 2015-10-27 (annotated)

Committer:
co657_frmb
Date:
Tue Oct 27 10:28:53 2015 +0000
Revision:
2:f62652cae975
Parent:
1:f346d04ccbad
Child:
3:2d8982c06eee
Minor updates, very much under construction still.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
co657_frmb 0:215c9308dc52 1 /*
co657_frmb 0:215c9308dc52 2 * gfx3d.cpp -- 3D stuff for MBED (just playing!)
co657_frmb 0:215c9308dc52 3 * Copyright (C) 2015 Fred Barnes, University of Kent <frmb@kent.ac.uk>
co657_frmb 0:215c9308dc52 4 */
co657_frmb 0:215c9308dc52 5
co657_frmb 0:215c9308dc52 6 /** gfx3d library
co657_frmb 0:215c9308dc52 7 *
co657_frmb 0:215c9308dc52 8 * This is a library for primitive 3D graphics. No classes, just C functions.
co657_frmb 0:215c9308dc52 9 */
co657_frmb 0:215c9308dc52 10
co657_frmb 0:215c9308dc52 11
co657_frmb 0:215c9308dc52 12 #include "mbed.h"
co657_frmb 0:215c9308dc52 13 #include "C12832.h"
co657_frmb 0:215c9308dc52 14 #include "gfx3d.h"
co657_frmb 0:215c9308dc52 15
co657_frmb 0:215c9308dc52 16
co657_frmb 1:f346d04ccbad 17 /** rotates a base set of points into a new set (demoscene style)
co657_frmb 1:f346d04ccbad 18 *
co657_frmb 1:f346d04ccbad 19 * @param src Source points.
co657_frmb 1:f346d04ccbad 20 * @param dst Destination points.
co657_frmb 1:f346d04ccbad 21 * @param npnts Number of points.
co657_frmb 1:f346d04ccbad 22 * @param a Angle to rotate by (0-255).
co657_frmb 0:215c9308dc52 23 */
co657_frmb 0:215c9308dc52 24 void gfx3d_rotate_demo (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const angle_t a)
co657_frmb 0:215c9308dc52 25 {
co657_frmb 0:215c9308dc52 26 float sinval = gfx3d_sin (a);
co657_frmb 0:215c9308dc52 27 float cosval = gfx3d_cos (a);
co657_frmb 0:215c9308dc52 28 int i;
co657_frmb 0:215c9308dc52 29
co657_frmb 0:215c9308dc52 30 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 31 float x1 = (src[i].x * cosval) + (src[i].y * sinval);
co657_frmb 0:215c9308dc52 32 float y1 = (src[i].y * cosval) - (src[i].x * sinval);
co657_frmb 0:215c9308dc52 33 float z1 = (src[i].z * cosval) - (x1 * sinval);
co657_frmb 0:215c9308dc52 34 float t;
co657_frmb 0:215c9308dc52 35
co657_frmb 0:215c9308dc52 36 dst[i].x = (x1 * cosval) + (src[i].z * sinval);
co657_frmb 0:215c9308dc52 37 t = (y1 * cosval) + (z1 * sinval);
co657_frmb 0:215c9308dc52 38 dst[i].z = (z1 * cosval) - (y1 * sinval);
co657_frmb 0:215c9308dc52 39 dst[i].y = t;
co657_frmb 0:215c9308dc52 40 }
co657_frmb 0:215c9308dc52 41
co657_frmb 0:215c9308dc52 42 }
co657_frmb 0:215c9308dc52 43
co657_frmb 0:215c9308dc52 44
co657_frmb 0:215c9308dc52 45 /*
co657_frmb 0:215c9308dc52 46 * translates a set of 3D points. 'src' and 'dst' can be the same
co657_frmb 0:215c9308dc52 47 */
co657_frmb 0:215c9308dc52 48 void gfx3d_translate (const g3d_p3_t *src, g3d_p3_t *dst, const int npnts, const g3d_p3_t tx)
co657_frmb 0:215c9308dc52 49 {
co657_frmb 0:215c9308dc52 50 int i;
co657_frmb 0:215c9308dc52 51
co657_frmb 0:215c9308dc52 52 if (tx.x != 0.0f) {
co657_frmb 0:215c9308dc52 53 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 54 dst[i].x = src[i].x + tx.x;
co657_frmb 0:215c9308dc52 55 }
co657_frmb 0:215c9308dc52 56 } else if (src != dst) {
co657_frmb 0:215c9308dc52 57 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 58 dst[i].x = src[i].x;
co657_frmb 0:215c9308dc52 59 }
co657_frmb 0:215c9308dc52 60 }
co657_frmb 0:215c9308dc52 61 if (tx.y != 0.0f) {
co657_frmb 0:215c9308dc52 62 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 63 dst[i].y = src[i].y + tx.y;
co657_frmb 0:215c9308dc52 64 }
co657_frmb 0:215c9308dc52 65 } else if (src != dst) {
co657_frmb 0:215c9308dc52 66 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 67 dst[i].y = src[i].y;
co657_frmb 0:215c9308dc52 68 }
co657_frmb 0:215c9308dc52 69 }
co657_frmb 0:215c9308dc52 70 if (tx.z != 0.0f) {
co657_frmb 0:215c9308dc52 71 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 72 dst[i].z = src[i].z + tx.z;
co657_frmb 0:215c9308dc52 73 }
co657_frmb 0:215c9308dc52 74 } else if (src != dst) {
co657_frmb 0:215c9308dc52 75 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 76 dst[i].z = src[i].z;
co657_frmb 0:215c9308dc52 77 }
co657_frmb 0:215c9308dc52 78 }
co657_frmb 0:215c9308dc52 79 }
co657_frmb 0:215c9308dc52 80
co657_frmb 0:215c9308dc52 81
co657_frmb 0:215c9308dc52 82 /*
co657_frmb 0:215c9308dc52 83 * projects a set of 3D points into a 2D space (pretty crude)
co657_frmb 0:215c9308dc52 84 */
co657_frmb 0:215c9308dc52 85 void gfx3d_project (const g3d_p3_t *src, g3d_2p3_t *dst, const int npnts)
co657_frmb 0:215c9308dc52 86 {
co657_frmb 0:215c9308dc52 87 int i;
co657_frmb 0:215c9308dc52 88
co657_frmb 0:215c9308dc52 89 for (i=0; i<npnts; i++) {
co657_frmb 0:215c9308dc52 90 float ez = src[i].z;
co657_frmb 0:215c9308dc52 91
co657_frmb 0:215c9308dc52 92 dst[i].z = (int)(ez * G3D_ZBSCALE) + G3D_ZBADD;
co657_frmb 0:215c9308dc52 93 ez += G3D_Z_DEPTH;
co657_frmb 0:215c9308dc52 94 dst[i].x = (int)((src[i].x / ez) * G3D_X_SCALE) + G3D_X2_SHIFT;
co657_frmb 0:215c9308dc52 95 dst[i].y = (int)((src[i].y / ez) * G3D_Y_SCALE) + G3D_Y2_SHIFT;
co657_frmb 0:215c9308dc52 96 }
co657_frmb 0:215c9308dc52 97 }
co657_frmb 0:215c9308dc52 98
co657_frmb 0:215c9308dc52 99
co657_frmb 0:215c9308dc52 100 /*
co657_frmb 0:215c9308dc52 101 * takes a set of 8 projected points and draws a wireframe cube on the given LCD. FIXME: only interested in the buffer ops..
co657_frmb 0:215c9308dc52 102 */
co657_frmb 0:215c9308dc52 103 void gfx3d_wirecube (const g3d_2p3_t *src, C12832 &lcd)
co657_frmb 0:215c9308dc52 104 {
co657_frmb 0:215c9308dc52 105 lcd.line (src[0].x, src[0].y, src[1].x, src[1].y, 1);
co657_frmb 0:215c9308dc52 106 lcd.line (src[1].x, src[1].y, src[2].x, src[2].y, 1);
co657_frmb 0:215c9308dc52 107 lcd.line (src[2].x, src[2].y, src[3].x, src[3].y, 1);
co657_frmb 0:215c9308dc52 108 lcd.line (src[3].x, src[3].y, src[0].x, src[0].y, 1);
co657_frmb 0:215c9308dc52 109
co657_frmb 0:215c9308dc52 110 lcd.line (src[4].x, src[4].y, src[5].x, src[5].y, 1);
co657_frmb 0:215c9308dc52 111 lcd.line (src[5].x, src[5].y, src[6].x, src[6].y, 1);
co657_frmb 0:215c9308dc52 112 lcd.line (src[6].x, src[6].y, src[7].x, src[7].y, 1);
co657_frmb 0:215c9308dc52 113 lcd.line (src[7].x, src[7].y, src[4].x, src[4].y, 1);
co657_frmb 0:215c9308dc52 114
co657_frmb 0:215c9308dc52 115 lcd.line (src[0].x, src[0].y, src[4].x, src[4].y, 1);
co657_frmb 0:215c9308dc52 116 lcd.line (src[1].x, src[1].y, src[5].x, src[5].y, 1);
co657_frmb 0:215c9308dc52 117 lcd.line (src[2].x, src[2].y, src[6].x, src[6].y, 1);
co657_frmb 0:215c9308dc52 118 lcd.line (src[3].x, src[3].y, src[7].x, src[7].y, 1);
co657_frmb 0:215c9308dc52 119 }