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#include "defs.h"
#include "fixed.h"
#include "pt.h"
#include <math.h>
#ifndef VERTEX_H
#define VERTEX_H
typedef struct VERTEX {
FIXED x;
FIXED y;
FIXED z;
} VERTEX;
static inline POINT viewportToScreen (POINT *point) {
// Convert a viewport coordinate to screen x, y
return createPoint(fixed_multiply(point->x, fixed_divide(WINDOW_WIDTH << FIX_SHIFT, viewport_width << FIX_SHIFT)),
fixed_multiply(point->y, fixed_divide(WINDOW_HEIGHT << FIX_SHIFT, viewport_height << FIX_SHIFT))
);
}
static inline POINT projectVertex(VERTEX *vertex) {
// Project a vertex to a point
POINT temp;
if (vertex->z != 0) {
// Make sure we don't divide by zero
temp = createPoint(fixed_multiply(vertex->x, fixed_divide(ZPlane << FIX_SHIFT, vertex->z)),
fixed_multiply(vertex->y, fixed_divide(ZPlane << FIX_SHIFT, vertex->z))
);
}
else {
temp = createPoint(0, 0);
}
temp = viewportToScreen(&temp);
return temp;
}
static inline VERTEX createVertex(FIXED x, FIXED y, FIXED z) {
// Create a vertex from data
VERTEX temp;
temp.x = x;
temp.y = y;
temp.z = z;
return temp;
}
static inline VERTEX addVertices(VERTEX *a, VERTEX *b) {
// Add two vertices together
VERTEX temp = createVertex(a->x + b->x, a->y + b->y, a->z + b->z);
return temp;
}
static inline void applyXRotation(VERTEX *vertex, FIXED xRotation) {
// Apply rotation to vertex on x-axis
FIXED sinTheta = float_to_fixed(sin(fixed_to_float(xRotation) * (3.14159 / 180)));
FIXED cosTheta = float_to_fixed(cos(fixed_to_float(xRotation) * (3.14159 / 180)));
FIXED y = vertex->y;
FIXED z = vertex->z;
vertex->y = fixed_multiply(y, cosTheta) - fixed_multiply(z, sinTheta);
vertex->z = fixed_multiply(z, cosTheta) + fixed_multiply(y, sinTheta);
}
static inline void applyYRotation(VERTEX *vertex, FIXED yRotation) {
// Apply rotation to vertex on y-axis
FIXED sinTheta = float_to_fixed(sin(fixed_to_float(yRotation) * (3.14159 / 180)));
FIXED cosTheta = float_to_fixed(cos(fixed_to_float(yRotation) * (3.14159 / 180)));
FIXED x = vertex->x;
FIXED z = vertex->z;
vertex->x = fixed_multiply(x, cosTheta) + fixed_multiply(z, sinTheta);
vertex->z = fixed_multiply(z, cosTheta) - fixed_multiply(x, sinTheta);
}
static inline void applyZRotation(VERTEX *vertex, FIXED zRotation) {
// Apply rotation to vertex on z-axis
FIXED sinTheta = float_to_fixed(sin(fixed_to_float(zRotation) * (3.14159 / 180)));
FIXED cosTheta = float_to_fixed(cos(fixed_to_float(zRotation) * (3.14159 / 180)));
FIXED x = vertex->x;
FIXED y = vertex->y;
vertex->x = fixed_multiply(x, cosTheta) - fixed_multiply(y, sinTheta);
vertex->y = fixed_multiply(y, cosTheta) + fixed_multiply(x, sinTheta);
}
static inline VERTEX crossProduct(VERTEX *a, VERTEX *b) {
// Calculate the cross product of two vertices
return createVertex(
fixed_multiply(a->y, b->z) - fixed_multiply(a->z, b->y),
fixed_multiply(a->z, b->x) - fixed_multiply(a->x, b->z),
fixed_multiply(a->x, b->y) - fixed_multiply(a->y, b->x)
);
}
static inline FIXED dotProduct(VERTEX *a, VERTEX *b) {
// Dot two vertices
FIXED product = fixed_multiply(a->x, b->x) +
fixed_multiply(a->y, b->y) +
fixed_multiply(a->z, b->z);
return product;
}
static inline void normalizeVertex(VERTEX *vertex) {
// Normalize (magnitude = 1) a vertex
float x = fixed_to_float(vertex->x);
float y = fixed_to_float(vertex->y);
float z = fixed_to_float(vertex->z);
float d = sqrtf(x*x + y*y + z*z);
vertex->x = float_to_fixed(fixed_to_float(vertex->x) / d);
vertex->y = float_to_fixed(fixed_to_float(vertex->y) / d);
vertex->z = float_to_fixed(fixed_to_float(vertex->z) / d);
}
#endif // VERTEX_H
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