OpenSource_hlworldviewer_zryfixed/src/camera.c

#include "camera.h"

void cameraRecompute(struct Camera *cam) {
	cam->dir = aVec3fNormalize(cam->dir);
	const struct AVec3f
			z = aVec3fNeg(cam->dir),
			x = aVec3fNormalize(aVec3fCross(cam->up, z)),
			y = aVec3fCross(z, x);
	cam->axes = aMat3fv(x, y, z);
	cam->orientation = aMat3fTranspose(cam->axes);
	cam->view_projection = aMat4fMul(cam->projection,
		aMat4f3(cam->orientation, aVec3fMulMat(cam->orientation, aVec3fNeg(cam->pos))));
}

void cameraProjection(struct Camera *cam, float znear, float zfar, float horizfov, float aspect) {
	const float w = 2.f * znear * tanf(horizfov / 2.f), h = w / aspect;
	cam->z_far = zfar;
	cam->z_near = znear;
	//aAppDebugPrintf("%f %f %f %f -> %f %f", near, far, horizfov, aspect, w, h);
	cam->projection = aMat4fPerspective(znear, zfar, w, h);
}

void cameraLookAt(struct Camera *cam, struct AVec3f pos, struct AVec3f at, struct AVec3f up) {
	cam->pos = pos;
	cam->dir = aVec3fNormalize(aVec3fSub(at, pos));
	cam->up = up;
	cameraRecompute(cam);
}

void cameraMove(struct Camera *cam, struct AVec3f v) {
	cam->pos = aVec3fAdd(cam->pos, aVec3fMulf(cam->axes.X, v.x));
	cam->pos = aVec3fAdd(cam->pos, aVec3fMulf(cam->axes.Y, v.y));
	cam->pos = aVec3fAdd(cam->pos, aVec3fMulf(cam->axes.Z, v.z));
}

void cameraRotateYaw(struct Camera *cam, float yaw) {
	const struct AMat3f rot = aMat3fRotateAxis(cam->up, yaw);
	cam->dir = aVec3fMulMat(rot, cam->dir);
}

void cameraRotatePitch(struct Camera *cam, float pitch) {
	/* TODO limit pitch */
	const struct AMat3f rot = aMat3fRotateAxis(cam->axes.X, pitch);
	cam->dir = aVec3fMulMat(rot, cam->dir);
}