Added files

1 files changed, 112 insertions, 0 deletions

diff --git a/src/vertex.h b/src/vertex.h
new file mode 100644
index 0000000..7880495
--- /dev/null
+++ b/src/vertex.h
@@ -0,0 +1,112 @@
+#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