//sets the vtm to be the virw transfermation defined by the 2D View structure
void matrix_setView2D(Matrix *vtm, View2D *view){
matrix_identity(vtm);
matrix_translate2D(vtm, -view->vrp.val[0], -view->vrp.val[1]);
matrix_rotateZ(vtm, view->x.val[0], -view->x.val[1]);
matrix_scale2D(vtm, (view->screenx / view->dx), (-view->screenx / view->dx)); // S(C/ du, R/ dv) where dv = du*R/ C
matrix_translate2D(vtm, (view->screenx / 2.0), (view->screeny / 2.0));
}
void matrix_setView2D(Matrix *vtm, View2D *view){
if(NULL != vtm && NULL != view){
float dv = (view->dx*view->screeny)/view->screenx;
matrix_identity(vtm);
matrix_print(vtm, stdout);
matrix_translate2D(vtm, -view->vrp.val[0], -view->vrp.val[1]);
matrix_rotateZ(vtm, view->x.val[0], -view->x.val[1]);
matrix_scale2D(vtm, view->screenx/view->dx, -view->screeny/dv);
matrix_translate2D(vtm, view->screenx/2, view->screeny/2);
}
}
/*
* Matrix operand to add a rotation about the Z axis to the tail of the module’s list
*/
void module_rotateZ(Module *md, double cth, double sth){
if(!md){
printf("Null md passed to module_rotateZ\n");
return;
}
Element *e;
Matrix m;
matrix_identity(&m);
matrix_rotateZ(&m, cth, sth);
e = element_init(ObjMatrix, &m);
module_insert(md, e);
}
void view_rotate_circle(Polygon* poly_vrp, Point* center, int sides, double scale, double thetax, double thetay, double thetaz){
if(NULL != poly_vrp){
//make a unit circle of "sides" number fo sides and store the points in the poly_vrp
int i;
double x, z;
polygon_init(poly_vrp);
Point p[sides];
Matrix LTM;
matrix_identity(<M);
matrix_scale(<M, scale, scale, scale);
matrix_rotateX(<M, cos(thetax*M_PI/180), sin(thetax*M_PI/180));
matrix_rotateY(<M, cos(thetay*M_PI/180), sin(thetay*M_PI/180));
matrix_rotateZ(<M, cos(thetaz*M_PI/180), sin(thetaz*M_PI/180));
matrix_translate(<M, center->val[0], center->val[1], center->val[2]);
for(i=0; i<sides; i++){
x = cos( i * M_PI * 2.0 / sides );
z = sin( i * M_PI * 2.0 / sides );
point_set3D(&p[i], x, 0.1, z);
}
polygon_set(poly_vrp, sides, &p[0]);
matrix_xformPolygon(<M, poly_vrp);
}
}
int main(int argc, char *argv[]) {
Image *src;
const int rows = 600;
const int cols = 800;
const int Resolution = 50;
Color white;
Color Grey;
Color dkGrey;
Color Red;
Color Blue;
Point unitCircle[Resolution];
Point unitSquare[4];
Point pt[Resolution];
Point ptt[Resolution];
int i, j, index = 0;
Matrix VTM, GTM, LTM;
Polygon *ship[50];
Color shipColor[50];
double theta = 0.0;
double phaserAngle = 0.0;
int firePhase = 0;
color_set(&Grey, 180/255.0, 180/255.0, 183/255.0);
color_set(&dkGrey, 140/255.0, 140/255.0, 143/255.0);
color_set(&Red, 250/255.0, 40/255.0, 40/255.0);
color_set(&Blue, 30/255.0, 20/255.0, 250/255.0);
if(argc > 1) {
theta = atoi(argv[1]);
}
printf("Drawing ship with orientation %.2f degrees\n", theta);
if(argc > 2) {
phaserAngle = atoi(argv[2]);
firePhase = 1;
printf("Drawing phaser with angle %.2f degrees\n", phaserAngle);
}
srand(42);
src = image_create(rows, cols);
color_set(&white, 1.0, 1.0, 1.0);
for(i=0; i<rows; i++){
for(j=0; j<cols; j++){
if((rand()%50) == 13){
image_setColor(src, i, j, white);
}
}
}
// initialize the three matrices
matrix_identity(&VTM);
matrix_identity(>M);
matrix_identity(<M);
// Fix world coordinates as normal (x, y)
// give the view window an origin at -180m, -150m
// size is a 4x3 ratio
// VTM = T(0, rows-1)S(cols/vx, rows/vy)T(180, 150)
matrix_translate2D(&VTM, 120, 100);
matrix_scale2D(&VTM, cols/(4*60), -rows/(3*60));
matrix_translate2D(&VTM, 0, rows-1);
printf("VTM\n");
matrix_print(&VTM, stdout);
// make a space ship oriented along the positive X axis
// use the LTM to move simple primitives into place
// use the GTM to rotate the ship
// use the VTM to change the view
// make a list of points that form the unit circle
for(i=0;i<Resolution;i++) {
point_set2D(&(unitCircle[i]),
cos( i * 2.0 * M_PI / (float)Resolution),
sin( i * 2.0 * M_PI / (float)Resolution));
}
// set up the unit square
point_set2D(&(unitSquare[0]), 0, 0);
point_set2D(&(unitSquare[1]), 1, 0);
point_set2D(&(unitSquare[2]), 1, 1);
point_set2D(&(unitSquare[3]), 0, 1);
// build a set of polygons that form the ship in model space
// put the origin of the model between the engines
// outline for the main disk
matrix_identity(<M);
matrix_scale2D(<M, 31, 31);
// move it 20m along the X-axis
matrix_translate2D(<M, 60, 0);
// transform the circle points using LTM
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// add the polygon
matrix_print(<M, stdout);
ship[index] = polygon_createp(Resolution, pt);
shipColor[index++] = Red;
printf("Post-LTM\n");
polygon_print(ship[0], stdout);
// main disk
matrix_identity(<M);
matrix_scale2D(<M, 30, 30);
// move it 20m along the X-axis
matrix_translate2D(<M, 60, 0);
// transform the circle points using LTM
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// add the polygon
matrix_print(<M, stdout);
ship[index] = polygon_createp(Resolution, pt);
shipColor[index++] = Grey;
// central bridge disk
matrix_identity(<M);
matrix_scale2D(<M, 10, 10);
// move it 20m along the X-axis
matrix_translate2D(<M, 60, 0);
// transform the circle points using LTM
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// add the polygon
matrix_print(<M, stdout);
ship[index] = polygon_createp(Resolution, pt);
shipColor[index++] = dkGrey;
// make the body disk elongated along the X axis
matrix_identity(<M);
matrix_scale2D(<M, 30, 12);
matrix_translate2D(<M, 2.5, 0);
// transform the circle points using LTM
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// add the polygon
matrix_print(<M, stdout);
ship[index] = polygon_createp(Resolution, pt);
shipColor[index++] = Grey;
// make a trapezoidal strut out of the unit square
matrix_identity(<M);
matrix_translate2D(<M, -0.5, 0.0);
matrix_scale2D(<M, 10, 10);
matrix_shear2D(<M, .2, 0.0);
for(i=0;i<4;i++) {
matrix_xformPoint(<M, &(unitSquare[i]), &(pt[i]));
}
// move the strut out from the origin along the Y axis
matrix_identity(<M);
matrix_translate2D(<M, 0, 12);
for(i=0;i<4;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
matrix_print(<M, stdout);
ship[index] = polygon_createp(4, ptt);
shipColor[index++] = Grey;
// place the second strut
matrix_identity(<M);
matrix_scale2D(<M, 1, -1);
matrix_translate2D(<M, 0, -12);
for(i=0;i<4;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
ship[index] = polygon_createp(4, ptt);
shipColor[index++] = Grey;
// create an engine outline from the unit circle
matrix_identity(<M);
matrix_scale2D(<M, 31, 6);
// make the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// send one engine to the right location
matrix_identity(<M);
matrix_translate2D(<M, -5, 27);
// move the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
ship[index] = polygon_createp(Resolution, ptt);
shipColor[index++] = Blue;
// send the other engine to the right location
matrix_identity(<M);
matrix_translate2D(<M, -5, -27);
// move the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
ship[index] = polygon_createp(Resolution, ptt);
shipColor[index++] = Blue;
// create an engine
matrix_identity(<M);
matrix_scale2D(<M, 30, 5);
// make the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(unitCircle[i]), &(pt[i]));
}
// send one engine to the right location
matrix_identity(<M);
matrix_translate2D(<M, -5, 27);
// move the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
ship[index] = polygon_createp(Resolution, ptt);
shipColor[index++] = Grey;
// send the other engine to the right location
matrix_identity(<M);
matrix_translate2D(<M, -5, -27);
// move the engine
for(i=0;i<Resolution;i++) {
matrix_xformPoint(<M, &(pt[i]), &(ptt[i]));
}
// add the polygon
ship[index] = polygon_createp(Resolution, ptt);
shipColor[index++] = Grey;
// set up the phaser
if(firePhase) {
matrix_identity(<M);
matrix_scale2D(<M, 100, 2);
// orient the phaser
matrix_rotateZ(<M, cos(phaserAngle*M_PI/180.0), sin(phaserAngle*M_PI/180.0));
// translate it to the center of the disk and out
matrix_translate2D(<M,
60 + 30 * cos(phaserAngle*M_PI/180.0),
30 * sin(phaserAngle*M_PI/180.0) );
// use the unit square
for(i=0;i<4;i++) {
matrix_xformPoint(<M, &(unitSquare[i]), &(pt[i]));
}
// add the polygon
ship[index] = polygon_createp(4, pt);
shipColor[index++] = Red;
}
matrix_rotateZ(>M, cos(theta*M_PI/180.0), sin(theta*M_PI/180.0));
printf("GTM:\n");
matrix_print(>M, stdout);
printf("Pre-GTM/VTM\n");
polygon_print(ship[0], stdout);
for(i=0;i<index;i++) {
// multiply the polygon by the global transform matrix
matrix_xformPolygon(>M, ship[i]);
if(i==0) {
printf("Pre-VTM\n");
polygon_print(ship[i], stdout);
}
// multiply the polygon by the view transformation matrix
matrix_xformPolygon(&VTM, ship[i]);
if(i==0) {
printf("Pre-draw\n");
polygon_print(ship[i], stdout);
}
// draw the polygon
polygon_drawFill(ship[i], src, shipColor[i]);
}
image_write(src, "space.ppm");
image_free(src);
return(0);
}